**6.4 Adverse pathways**

Livestock can also have an effect on food security by spreading diseases to people via carriers such as biting flies and contaminated animal source foods; these diseases reduce people's productivity by limiting their capacity to produce food or labour to earn money to buy food. With 13 major zoonotic illnesses killing 2.2 million people per year, mostly in low- and middle-income countries [53], livestock has a considerable impact on human nutrition and health. Livestock keeping may

also increase the probability of zoonotic disease or indirectly affect human health through contamination of water bodies which are the negative influences. Some of the most common diseases in humans, such as measles, influenza, and diphtheria, have always been transferred by the animals they owned, a phenomenon is known as the 'fatal gift of livestock' [54]. Environmental enteric dysfunction (EED)—an important risk factor for stunting—is associated with chronic inflammation in the intestines of young children and asymptomatic infections by diverse enteric pathogens including those present in livestock manure [55].

In developed and developing countries alike, antimicrobial-resistant pathogens, often associated with the intensification of production systems, are commonly found in animals, animal food products, and agro-food environments [56]. Additionally, women are more at risk of zoonotic diseases because they are more likely to be exposed and maybe particularly vulnerable [57]. Much of the existing burden and danger may indeed be reduced if better disease control technology and institutions were used, as well as investments in zoonosis control innovations. Increased consumption of animal-derived foods, on the other hand, may increase the risk of food-borne illness or the emergence of chronic diseases, both of which would have a detrimental influence on human nutrition. Overconsumption of foods of animal origin can have a negative influence on human health and well-being, affecting both entire societies and households. Overeating fatty red meats and hard cheeses, which contain more saturated fats, can cause cardiovascular disease, while excessive eating of processed meats like bacon and ham has been linked to several cancers [58]. Increased intake of highenergy meat, milk, and eggs contributes to global obesity as well. The physical activity in livestock rearing is much higher causing higher energy expenditure and ultimately affecting nutrition and health. Other than this competition of natural resources like land, water, and other agricultural products are other factors that can negatively influence nutrition. Recently the lack of sustainability of livestock production systems is also been widely discussed considering the ill effects on the environment. But facts need to be checked before de-promoting livestock production and consumption of ASF based on the sustainability criteria. This is discussed in the below section.


Data from the mortality and leaf-feeding laboratory bioassays showed significant (P<0.05) insecticide effects in that both imidacloprid and thiamethoxam, applied at planting with the seed piece, were significantly (P<0.05) more effective in reducing foliage consumption by CPB larvae from planting (23 Apr) through 7 Jul under both the low and high rainfall regimens compared with plants that were treated with dinotefuran or plants that received no insecticide. The interaction showed that plants treated with dinotefuran, under the low rainfall regimen, were significantly more effective in reducing leaf-feeding damage than plants that received no insecticide only from planting through 7 Jun; dinotefuran was ineffective in reducing foliage consumption under the high rainfall regimen for all dates observed as compared with plants that received no insecticide. Similarly, leaves from plants treated with either imidacloprid or thiamethoxam at planting resulted in significantly higher CPB mortality from May through mid-July under the low rainfall regimen and through mid-June under the high rainfall regimen as compared with CPB mortality on plants treated with dinotefuran or on plants that received no insecticide. As observed with the leaf-feeding bioassay, CPB mortality was significantly higher on plants treated with

production.

imidacloprid or thiamethoxam.

Leafhopper (Homoptera: Cicadellidae) with At-Plant Applications of Imidacloprid, Thiamethoxam or … 195

**Figure 5.** Effect of two levels of simulated rainfall on damage caused by potato leafhopper on potatoes treated with neonicotinoids at planting, Bridgeton, NJ. 2007.

#### **4. Discussion**

The CPB mortality bioassay showed that imidacloprid and thiamethoxam were more toxic to CPB larvae than dinotefuran during May and early June, but mortality of CPB larvae for all treatments declined over time (Fig. 1). It is likely that the continual simulated rainfall was partially responsible for this decrease in efficacy since dinotefuran, the most soluble material, was effective against CPB larvae early with the low amount of simulated rainfall, but was not effective at any time with the high amount of rainfall, suggesting that the material was leached from the soil before the potato plants had enough root matter to absorb the insecticide. Mortality would also decline over time because the material is no

**Figure 5.** Effect of two levels of simulated rainfall on damage caused by potato leafhopper on potatoes

23-Jun 25-Jun 27-Jun 29-Jun 1-Jul 3-Jul 5-Jul 7-Jul 9-Jul

a a

23-Jun 25-Jun 27-Jun 29-Jun 1-Jul 3-Jul 5-Jul 7-Jul 9-Jul

**High rainfall** c

a a

**Low rainfall** c

Venom Admire Platinum Ck

> a a

Venom Admire Platinum Ck

> b b

The CPB mortality bioassay showed that imidacloprid and thiamethoxam were more toxic to CPB larvae than dinotefuran during May and early June, but mortality of CPB larvae for all treatments declined over time (Fig. 1). It is likely that the continual simulated rainfall was partially responsible for this decrease in efficacy since dinotefuran, the most soluble material, was effective against CPB larvae early with the low amount of simulated rainfall, but was not effective at any time with the high amount of rainfall, suggesting that the material was leached from the soil before the potato plants had enough root matter to absorb the insecticide. Mortality would also decline over time because the material is no

treated with neonicotinoids at planting, Bridgeton, NJ. 2007.

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

**LH dam. rating (0-5)**

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

c

a

a

c

b

a

**LH dam. rating (0-5)**

**4. Discussion**

longer available in the foliage when the CPB were placed on the leaves in the petri dish, as the bioassay was conducted from 37 to 70 days after the in-furrow treatment applications. It is also possible that CPB mortality within all treatments declined over time because the laboratory test larvae were field-harvested from an untreated potato nursery, and only large larvae (3rd and 4th instars) were available in late June whereas only small larvae (1st and 2nd instars) were available in late May and early June, and only adults were available in July. Large CPB larvae and adults are generally more difficult to intoxicate than small larvae [24,25,26]. Further, mortality of CPB on leaves from plants treated with thiamethoxam was significantly (P=0.05) higher than that of all other treatments, including imidacloprid, under the low rainfall regimen on 28 Jun and 5 Jul, the last two test dates, suggesting that thiamethoxam remains more active in the plant over a longer period of time. Plants from soybean seeds that had been treated with with thiamethoxam resulted in significantly fewer aphid numbers than did imidacloprid-treated plants after 3 weeks, likely due to faster imidacloprid metabolism in the plant, which would result in reduced insecticide activity over a shorter time [27]. However, the difference between imidacloprid and thiamethoxam observed in the laboratory trials was not observed in the field trial, possibly because the final CPB larval field count was conducted on 25 June. Also, the effect of high amounts of simulated rainfall may be more pronounced in the greenhouse pots than under actual field production.

Similarly, the percentage leaf tissue consumed by larvae was significantly (P<0.05) higher with dinotefuran and the untreated than with imidacloprid or thiamethoxam on all dates recorded. However, dinotefuran resulted in significantly less leaf tissue consumption than was observed with plants that received no insecticide in late May and early June (Fig. 2) only under the low rainfall regimen; there were no significant differences between dinotefuran and plants that received no insecticide under the high rainfall regimen, again indicating that rainfall level impacted the effectivess of dinotefuran more so than that of imidacloprid or thiamethoxam.

Data from the mortality and leaf-feeding laboratory bioassays showed significant (P<0.05) insecticide effects in that both imidacloprid and thiamethoxam, applied at planting with the seed piece, were significantly (P<0.05) more effective in reducing foliage consumption by CPB larvae from planting (23 Apr) through 7 Jul under both the low and high rainfall regimens compared with plants that were treated with dinotefuran or plants that received no insecticide. The interaction showed that plants treated with dinotefuran, under the low rainfall regimen, were significantly more effective in reducing leaf-feeding damage than plants that received no insecticide only from planting through 7 Jun; dinotefuran was ineffective in reducing foliage consumption under the high rainfall regimen for all dates observed as compared with plants that received no insecticide. Similarly, leaves from plants treated with either imidacloprid or thiamethoxam at planting resulted in significantly higher CPB mortality from May through mid-July under the low rainfall regimen and through mid-June under the high rainfall regimen as compared with CPB mortality on plants treated with dinotefuran or on plants that received no insecticide. As observed with the leaf-feeding bioassay, CPB mortality was significantly higher on plants treated with dinotefuran under the low rainfall regimen only through early June, as compared with plants that received no insecticide; CPB mortality on plants treated with dinotefuran under the high rainfall regimen were not significantly different than the untreated on all dates observed. A highly water-soluble systemic insecticide may not provide long-term control or regulation compared with a less water-soluble systemic insecticide [28]. Mortality of CPB gradually on foliage treated with imidacloprid or thiamethoxam declined over time from May through July for both rainfall regimens, and mortality declined more quickly with dinotefuran for the low rainfall regimen as compared with imidacloprid or thiamethoxam.

Effect of Simulated Rainfall on the Control of Colorado Potato Beetle (Coleoptera: Chrysomelidae) and Potato

Overall, the effectiveness of dinotefuran against CPB and PLH was influenced by the amount of rainfall significantly more than either imidacloprid or thiamethoxam. Under a high rainfall regimen, plots that received a treatment of dinotefuran were not significantly different from plots that received no insecticide for either CPB mortality or for CPB leaf consumption, and under a low rainfall regimen the effectiveness of dinotefuran against CPB was significantly shorter over time than either imidacloprid or thiamethoxam. It has to be mentioned that our findings reflect the worst-case scenarios for rainfall (maximum rainfall total of 60.96 cm [24"] laboratory and 50.8 cm [20"] field) and that under practical conditions lower amounts of rainfall would likely naturally occur. These high rainfall amounts likely caused exaggerated leaching of all of the neonicotinoids, especially the highly soluble

Results of the present study show that rainfall has an impact on effectiveness of soil-applied imidacloprid, dinotefuran and thiamethoxam for both CPB and PLH control in white potatoes. However, growers should not rotate imidacloprid or dinotefuran with thiamethoxam as part of their resistance management program. Alyokhin et al. (31) showed that the correlation for LC50 values for imidacloprid and thiamethoxam was highly significant using diet incorporation bioassays, and that there was substantial crossresistance among three neonicotinoid insecticides. Further, Mota-Sanchez et al. (32) reported that cross-resistance was observed with all 10 different neonicotinoids in a bioassay using topical applications. They concluded that the rotation of imidacloprid with other neonicotinoids may not be an effective long-term resistance management strategy. For effective insecticide resistance management, control of CPB should not depend exclusively on the neonicotinoid class of insecticides. It is important to use all available effective pest management tools, including crop rotation, border treatments, and non-neonicotinoid

*Rutgers- the State University, Department of Entomology, New Brunswick, NJ, USA*

*Rutgers- the State University, Department of Plant Biology and Pathology, New Brunswick, NJ,*

[1] Capinera, J.L. 2001a. Handbook of Vegetable Pests. Academic Press, New York, NY. pg.

dinotefuran, resulting in reduced control of the CPB and PLH.

(different class) insecticides.

*Syngenta Crop Protection, Elmer, NJ, USA*

**Author details**

Gerald M. Ghidiu

Erin M. Hitchner

**5. References**

96-98.

*USA*

Melvin R. Henninger

Leafhopper (Homoptera: Cicadellidae) with At-Plant Applications of Imidacloprid, Thiamethoxam or … 197

Data from the field trials for CPB mortality are similar to the CPB mortality trials in the laboratory bioassay, with significant insecticide effects in that plots treated with either Admire or Platinum at planting resulting in significantly fewer CPB/3 hills through late June under both the low and high rainfall regimens. Plots treated with dinotefuran had significantly fewer CPB/3 hills than did plots that received no insecticide only on 2 Jun and only under the low rainfall regimen; there were no significant differences for CPB/3 hills between plots treated with dinotefuran and the no-insecticide plots on all dates observed under the high rainfall regimen. As was recorded with the CPB larval counts in the field and the laboratory trials, dinotefuran was less effective than either imidacloprid or thiamethoxam under the low rainfall regimen, and dinotefuran was ineffective under the high rainfall regimen. Further, both imidacloprid and thiamethoxam remained effective for a greater time period after planting than did dinotefuran, possibly due to the lower solubility of imidacloprid and thiamethoxam. Field data for the percentage defoliation caused by CPB feeding were similar to that observed for CPB mortality. Significant insecticide effects were observed as defoliation increased over time. Defoliation in plots treated with either imidacloprid or thiamethoxam remained low through all observation dates, but defoliation in plots treated with dinotefuran was not significantly different than plots that received no insecticide on any observation date. These data agree with [29], who reported that potatoes treated with dinotefuran had significantly greater percentage defoliation than either imidacloprid or thiamethoxam in white potatoes with in-furrow treatments.

The PLH data show significant insecticide and significant rainfall effects. Under the low rainfall regimen, all insecticides resulted in significantly less PLH damage through the season (mid- June through mid-July) as compared with the plots that received no insecticide; no significant effects among the three insecticides were observed for either observation date. However, under the high rainfall regimen, plots treated with either imidacloprid or thiamethoxam resulted in significantly less (P<0.05) PLH damage early in the season (25 Jun) than did all other treatments, but only plots treated with thiamethoxam had significantly (P<0.05) less PLH damage than all other treatments on 7 July. Our data agrees with that of [30], who reported that thiamethoxam provided longer and more consistent protection of snap beans from PLH than did imidacloprid when applied as a seed treatment. They concluded that thiamethoxam had greater physiological activity against PLH than did imidacloprid.

Overall, the effectiveness of dinotefuran against CPB and PLH was influenced by the amount of rainfall significantly more than either imidacloprid or thiamethoxam. Under a high rainfall regimen, plots that received a treatment of dinotefuran were not significantly different from plots that received no insecticide for either CPB mortality or for CPB leaf consumption, and under a low rainfall regimen the effectiveness of dinotefuran against CPB was significantly shorter over time than either imidacloprid or thiamethoxam. It has to be mentioned that our findings reflect the worst-case scenarios for rainfall (maximum rainfall total of 60.96 cm [24"] laboratory and 50.8 cm [20"] field) and that under practical conditions lower amounts of rainfall would likely naturally occur. These high rainfall amounts likely caused exaggerated leaching of all of the neonicotinoids, especially the highly soluble dinotefuran, resulting in reduced control of the CPB and PLH.

Results of the present study show that rainfall has an impact on effectiveness of soil-applied imidacloprid, dinotefuran and thiamethoxam for both CPB and PLH control in white potatoes. However, growers should not rotate imidacloprid or dinotefuran with thiamethoxam as part of their resistance management program. Alyokhin et al. (31) showed that the correlation for LC50 values for imidacloprid and thiamethoxam was highly significant using diet incorporation bioassays, and that there was substantial crossresistance among three neonicotinoid insecticides. Further, Mota-Sanchez et al. (32) reported that cross-resistance was observed with all 10 different neonicotinoids in a bioassay using topical applications. They concluded that the rotation of imidacloprid with other neonicotinoids may not be an effective long-term resistance management strategy. For effective insecticide resistance management, control of CPB should not depend exclusively on the neonicotinoid class of insecticides. It is important to use all available effective pest management tools, including crop rotation, border treatments, and non-neonicotinoid (different class) insecticides.

#### **Author details**

196 Agricultural Chemistry

treatments.

PLH than did imidacloprid.

dinotefuran under the low rainfall regimen only through early June, as compared with plants that received no insecticide; CPB mortality on plants treated with dinotefuran under the high rainfall regimen were not significantly different than the untreated on all dates observed. A highly water-soluble systemic insecticide may not provide long-term control or regulation compared with a less water-soluble systemic insecticide [28]. Mortality of CPB gradually on foliage treated with imidacloprid or thiamethoxam declined over time from May through July for both rainfall regimens, and mortality declined more quickly with dinotefuran for the low rainfall regimen as compared with imidacloprid or thiamethoxam.

Data from the field trials for CPB mortality are similar to the CPB mortality trials in the laboratory bioassay, with significant insecticide effects in that plots treated with either Admire or Platinum at planting resulting in significantly fewer CPB/3 hills through late June under both the low and high rainfall regimens. Plots treated with dinotefuran had significantly fewer CPB/3 hills than did plots that received no insecticide only on 2 Jun and only under the low rainfall regimen; there were no significant differences for CPB/3 hills between plots treated with dinotefuran and the no-insecticide plots on all dates observed under the high rainfall regimen. As was recorded with the CPB larval counts in the field and the laboratory trials, dinotefuran was less effective than either imidacloprid or thiamethoxam under the low rainfall regimen, and dinotefuran was ineffective under the high rainfall regimen. Further, both imidacloprid and thiamethoxam remained effective for a greater time period after planting than did dinotefuran, possibly due to the lower solubility of imidacloprid and thiamethoxam. Field data for the percentage defoliation caused by CPB feeding were similar to that observed for CPB mortality. Significant insecticide effects were observed as defoliation increased over time. Defoliation in plots treated with either imidacloprid or thiamethoxam remained low through all observation dates, but defoliation in plots treated with dinotefuran was not significantly different than plots that received no insecticide on any observation date. These data agree with [29], who reported that potatoes treated with dinotefuran had significantly greater percentage defoliation than either imidacloprid or thiamethoxam in white potatoes with in-furrow

The PLH data show significant insecticide and significant rainfall effects. Under the low rainfall regimen, all insecticides resulted in significantly less PLH damage through the season (mid- June through mid-July) as compared with the plots that received no insecticide; no significant effects among the three insecticides were observed for either observation date. However, under the high rainfall regimen, plots treated with either imidacloprid or thiamethoxam resulted in significantly less (P<0.05) PLH damage early in the season (25 Jun) than did all other treatments, but only plots treated with thiamethoxam had significantly (P<0.05) less PLH damage than all other treatments on 7 July. Our data agrees with that of [30], who reported that thiamethoxam provided longer and more consistent protection of snap beans from PLH than did imidacloprid when applied as a seed treatment. They concluded that thiamethoxam had greater physiological activity against Gerald M. Ghidiu *Rutgers- the State University, Department of Entomology, New Brunswick, NJ, USA*

Erin M. Hitchner *Syngenta Crop Protection, Elmer, NJ, USA*

Melvin R. Henninger *Rutgers- the State University, Department of Plant Biology and Pathology, New Brunswick, NJ, USA*

#### **5. References**

[1] Capinera, J.L. 2001a. Handbook of Vegetable Pests. Academic Press, New York, NY. pg. 96-98.

[2] Hare, J.D. 1980. Impact of defoliation by the Colorado potato beetle on potato yields. J. Econ. Entomol. 73: 369-373.

Effect of Simulated Rainfall on the Control of Colorado Potato Beetle (Coleoptera: Chrysomelidae) and Potato

[17] Harris, C.R. and B.T. Bowman. 1981. The relationship of insecticide solubility in water

[18] Cloyd, R.A., K.A. Williams, F.J. Byrne and K.E. Kemp. 2012. Interactions of light intensity, insecticide concentration, and time on the efficacy of systemic insecticides in suppressing populations of the sweetpotato whitefly (Hemiptera: Aleyrodidae) and the

[20] Miles. 1993. Environmental fate of imidacloprid. Miles Report No. 105008 to

[21] Wakita, T., N. Yasui, E. Yamada and D. Kishi. 2005. Development of a novel insecticide,

[22] Brockman, F.E., W.B. Duke and J.F. Hunt. 1975. A rainfall simulator for pesticide

[24] Ferro, D.N., Q. Yuan, A. Slocombe and A.F. Tuttle. 1993. Residual activity of insecticides under field conditions for controlling the Colorado potato beetle (Coleoptera:

[25] Zehnder, G. 1986. Timing of insecticides for control of Colorado potato beetle (Coleoptera: Chrysomelidae) in eastern Virginia based on differential susceptibility of

[26] Lu, W., X. Shi, W. Guo, W. Jiang, Z. Xia, W. Fu and G. Li. 2011. Susceptibilities of *Leptinotarsa decemlineata* (Say) in the north Xinjiang Uygur autonomous region in China to two biopesticides and three conventional insecticides. J. Agric. Urban Entomol. 27:

[27] Magalhaes, L.C., T.E. Hunt and B.D. Siegfried. 2009. Efficacy of neonicotinoid seed treatments to reduce soybean aphid populations under field and controlled conditions

[28] Cloyd, R.A. 2010.  Western Nursery Landscape Association e-Newsletter, 1 Feb 2010.

[29] Kuhar, T.P., H.B. Doughty, E. Hitchner and M. Cassell. 2007. Control of wireworms and other pests of potatoes with soil insecticides. *In*: Arthropod pest management research

[30] Nault, B.A., A.G. Taylor, M. Urwiler, T. Rabasey and W.D. Hutchison. 2003. Neonicotinoid seed treatments for managing potato leafhopper infestations in snap

on vegetables in Virginia. VPI&SU Eastern Shore AREC Report #306: 19.

citrus mealybug (Hemiptera: Pseudococcidae). J. Econ. Entomol. 105: 505-517. [19] Gupta, S., V.T. Gajbhinge and R.K. Gupta. 2008. Soil dissipation and leaching behavior of a neonicotinoid insecticide thiamethoxam. Bull. Environ. Contam. and Tox. 80: 431-

Department of Environmental Protection, Sacramento, CA. Miles, Inc. 8 pp.

[23] SAS Institute. 1989. User's guide: statistics. SAS Institute, Cary, NC.

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to toxicity in soil. J. Econ. Entomol. 74: 210-212.

dinotefuran. J. Pestic. Sci. 30: 122-123.

leaching studies. Weed Sci. 23: 533-525.

Chrysomelidae). J. Econ. Entomol. 86: 511-516.

life stages. J. Econ. Entomol. 79: 851-856.

in Nebraska. J. Econ. Entomol. 102: 187-195.

www.wnla.org/news\_list.php?artic\_idx=883

bean. Crop Protection 23: 147-154.

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338-340.

pp. 3-15.

10.1002/ps365

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Entomol. Soc. 57: 588-591.

University, Ithaca, NY.

[2] Hare, J.D. 1980. Impact of defoliation by the Colorado potato beetle on potato yields. J.

[3] Alyokhin, A., M. Baker, D. Mota-Sanchez, G. Dively and E. Grafius. 2008. Colorado

[4] Capinera, J.L. 2001b. Handbook of Vegetable Pests. Academic Press, New York, NY. pg.

[5] Peterson, A.G. and A.A. Granovsky. 1950. Relation of *Empoasca fabae* to hopperburn and

[6] Pienkowski, T.L. and R.T. Medler. 1964. Synoptic weather conditions associated with long-range movement of the potato leafhopper, *Empoasca fabae*, into Wisconsin. Ann.

[7] Taylor, P.S. 1993. Phenology of *Empoasca fabae* (Harris) (Homoptera: Cicadellidae) and development of spring-time migrant source populations. Ph.D. dissertation. Cornell

[8] Dively, G.P., P.A. Follett, J.J. Linduska and C.K. Roderick. 1998. Use of imidaclopridtreated row mixtures for Colorado Potato Beetle (Coleoptera: Chrysomelidae)

[9] Prabhaker, N., S.J. Castle, S.E. Naranjo, N.C. Toscano and J.G. Morse. 2011. Compatibility of two systemic neonicotinoids, imidacloprid and thiamethoxam, with

[10] Elbert, A., M. Haas, B. Springer, W. Thielert and R. Nauen. 2008. Applied aspects of

[11] Cassida, J.E. and G.B. Quistad. 1997. Safer and more effective insecticides for the future. *In:* D. Rosen [ed], Modern Agriculture and the Environment, Kluwer Academic, UK.,

[12] Maienfisch, P., M. Angst, F. Brandl, W. Fischer, D. Hofer, H. Kayser, W. Kobel, A. Rindlisbacher, R. Senn, A. Steinemann and J. Widmer. 2001. Chemistry and biology of thiamethoxam: a second generation neonicotinoid. Pest. Manag. Sci. 57: 906-913. doi:

[13] Sur, R. and A. Stork. 2003. Uptake, translocation and metabolism of imidacloprid in

[14] Gawlik, B.M., N. Sotiriou, E.A. Feicht, S. Schulte-Hostede and A. Kettrup. 1997. Alternatives for the determination of the soil adsorption coefficient Koc, of non-ionic

[15] Walker, A. 2000. A simple centrifugation technique for the extraction of soil solution to permit direct measurement of aqueous phase concentrations of pesticide. *In:* J. Cornejo and P. Jamet [ed.], Pesticide/soil interactions – some current research methods. Institute

[16] Toscano, N.C., B. Drake, F.J. Byrne, C. Gispert and E. Weber. 2007. Laboratory and field evaluations of neonicotinoid insecticides against the glassy-winged sharpshooter. *In:*

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[31] Alyokhin, A., G. Dively, M. Patterson, C. Castaldo, D. Rogers, M. Mahoney and J. Wollam. 2007. Resistance and cross-resistance to imidacloprid and thiamethoxam in the Colorado potato beetle, *Leptinotarsa decimlieata* (Say). Pest Manag. Sci 63: 32-41.

**Chapter 10**

© 2013 Echem and Kabari, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2013 Echem and Kabari, licensee InTech. This is a paper distributed under the terms of the Creative Commons

**Heavy Metal Content in Bitter Leaf**

Ogbonda G. Echem and L. G. Kabari

http://dx.doi.org/10.5772/55604

**1. Introduction**

physical malaise.

(Radwan and Salama, 2006).

Additional information is available at the end of the chapter

presence of vitamins and mineral salts (Sobukola et al., 2007).

**(***Vernonia amygdalina***) Grown Along**

**Heavy Traffic Routes in Port Harcourt**

The herb known as bitter leaf *(Vernonia amygdalina)* is a shrub or small tree that can reach 23 feet in height when fully grown. Bitter leaf has a grey or brown coloured bark, which has a rough texture and is flaked. The herb is an indigenous African plant; which grows in most parts of sub-Saharan Africa. The East African country of Tanzania is traditionally linked to this plant and can be found growing wild along the edges of agricultural fields. It is a medicinal plant and fresh bitter leaf is of great importance in human diet because of the

It is a very important protective food and useful for the maintenance of health and prevention and treatment of various diseases. Some principal chemical constituents found in bitter leaf herb are a class of compounds called steroid glycosides- type vernonioside B1 – these chemical substances possess a potent anti-parasitic, anti-tumour, and bactericidal effect. The bitter leaf is mainly employed as an agent in treating schistsomiasis, which is a disease caused by parasitic worms. It is also useful in the treatment of diarrhoea and general

Remedies made from bitter leaf are used in treating 25 common ailments in sub- Saharan African, these include common problems such as fever, and different kinds of intestine complaints, as well as parasite-induced diseases like malaria. Bitter leaf also helps to cleanse such vital organs of the body like the liver and the kidney. Bitter leaf is also used in the treatment of skin infections such as ringworm, rashes and eczema. However, bitter leaf and other vegetables contain both essential and toxic metals over a wide range of concentrations

[32] Mota-Sanchez, D., R. Hollingworth, E.J. Grafius and D.D. Moyer. 2006. Resistance and cross-resistance to neonicotinoid insecticides and spinosad in the Colorado potato beetle, *Leptinotarsa decemliata* (Say) (Coleoptera: Chrysomelidae). Pest Manag. Sci. 62: 30- 37.

## **Heavy Metal Content in Bitter Leaf (***Vernonia amygdalina***) Grown Along Heavy Traffic Routes in Port Harcourt**

Ogbonda G. Echem and L. G. Kabari

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/55604

#### **1. Introduction**

200 Agricultural Chemistry

37.

[31] Alyokhin, A., G. Dively, M. Patterson, C. Castaldo, D. Rogers, M. Mahoney and J. Wollam. 2007. Resistance and cross-resistance to imidacloprid and thiamethoxam in the

Colorado potato beetle, *Leptinotarsa decimlieata* (Say). Pest Manag. Sci 63: 32-41. [32] Mota-Sanchez, D., R. Hollingworth, E.J. Grafius and D.D. Moyer. 2006. Resistance and cross-resistance to neonicotinoid insecticides and spinosad in the Colorado potato beetle, *Leptinotarsa decemliata* (Say) (Coleoptera: Chrysomelidae). Pest Manag. Sci. 62: 30-

> The herb known as bitter leaf *(Vernonia amygdalina)* is a shrub or small tree that can reach 23 feet in height when fully grown. Bitter leaf has a grey or brown coloured bark, which has a rough texture and is flaked. The herb is an indigenous African plant; which grows in most parts of sub-Saharan Africa. The East African country of Tanzania is traditionally linked to this plant and can be found growing wild along the edges of agricultural fields. It is a medicinal plant and fresh bitter leaf is of great importance in human diet because of the presence of vitamins and mineral salts (Sobukola et al., 2007).

> It is a very important protective food and useful for the maintenance of health and prevention and treatment of various diseases. Some principal chemical constituents found in bitter leaf herb are a class of compounds called steroid glycosides- type vernonioside B1 – these chemical substances possess a potent anti-parasitic, anti-tumour, and bactericidal effect. The bitter leaf is mainly employed as an agent in treating schistsomiasis, which is a disease caused by parasitic worms. It is also useful in the treatment of diarrhoea and general physical malaise.

> Remedies made from bitter leaf are used in treating 25 common ailments in sub- Saharan African, these include common problems such as fever, and different kinds of intestine complaints, as well as parasite-induced diseases like malaria. Bitter leaf also helps to cleanse such vital organs of the body like the liver and the kidney. Bitter leaf is also used in the treatment of skin infections such as ringworm, rashes and eczema. However, bitter leaf and other vegetables contain both essential and toxic metals over a wide range of concentrations (Radwan and Salama, 2006).

© 2013 Echem and Kabari, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 Echem and Kabari, licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

#### **2. Heavy metal**

This is a member of an ill-defined subset of an element that exhibit metallic properties, which would mainly include the transition metals, some metalloids, lanthanides and actinides. Many different definitions have been proposed - some based on density, some based on atomic number or atomic weight and some on chemical properties or toxicity (Purseglove, 1977)

Heavy Metal Content in Bitter Leaf (*Vernonia amygdalina*)

catalytic functions and is important for both man and plants health and growth (Jeffery, 1992). The zinc content of normal plants tissues varies according to plant species, but it is

Generally vegetables appear to have the highest and lowest amount of heavy metals accumulated in their leaves and seed respectively e.g. beans, peppers, tomatoes, melons and peas show very low intake of heavy metals in their seed. Plant intake of heavy metals varies with soil PH. A study by Echem (2010) on cassava cultivated on oil polluted soil showed that

Heavy metals are associated with myriad adverse health effects, including allergic reaction, nephrotoxicity, and cancer. Humans are often exposed to heavy metals in various ways mainly through the inhalation of metals in the workplace or polluted neighbourhoods, or through the ingestion of food that contains high levels of heavy metals or paint chips that

The three heavy metals commonly cited as being of the greatest public health concern are cadmium, lead and mercury. There is no biological need for any of these three heavy metals. Exposure to cadmium can result in emphysema, renal failure, cardiovascular disease and perhaps cancer. The primary adverse health effect from exposure to lead is neurological impairment (particularly in children). Other adverse health effects associated with lead

Heavy metals have been reported to play positive and negative roles in human life (Slavesk et al., 1998; Divrikli et al., 2003; Dundar and Saglam, 2004). Some heavy metals like cadmium, lead and mercury are major contaminants of food supply and may be considered as very harmful to the environment since they do not biodegrade while others like iron, zinc and copper are essential for biochemical reactions in the body (Zaidi et al., 2005). Jarup (2003) and Sathawera et al., (2004) have reported that, most heavy metals are not biodegradable, have long biological half-lives and have the potential for accumulation in the different body organs leading to unwanted side effects. There is a strong link between micronutrient of plants, animals and humans, and the uptake and impact of contaminants in

Research findings by Divrikli et al. (2006) had shown that the concentration of essential elements in plants is conditional; it is affected by the characteristics of the soil and the ability of plants to selectively accumulate some metals. Sources of heavy metals for plants include rainfall in atmospheric polluted areas, heavy traffic as a result of high discharge of exhaust effluents- indiscriminate disposal of oil or fossil fuels by road side mechanics, - plant protection chemicals and fertilizers which could be absorbed through leaf blades

The aim of this research is to ascertain the level of heavy metals ingested by bitter leaf grown along heavy traffic routes. It is a well established fact that diesel, gasoline, lubricants, vehicle parts such as carburettors among others, contain heavy metals. The routes chosen for this study record the highest traffic density for heavy duty vehicles, lorries, buses and cars

usually within the range of 5 – 300mg/kg dry matter (Walsh, 1971).

soil contaminated with heavy metals cause contamination of foodstuffs.

contain lead Ifon, (1977).

include sterility in males and nephrotoxicity.

these organisms (Yuzbas, et al., 2003; Yaman et al., 2005).

(Kovacheva et al., 2000; Lozak et al., 2002; Sobukola et al., 2006).

Grown Along Heavy Traffic Routes in Port Harcourt 203

The primary anthropogenic sources of heavy metals are point sources such as mines, foundries, smelters, coal-burning power plants, and other sources such as combustion of wastes, and vehicle emissions. Some investigations carried out have shown that heavy metal accumulation in vegetables may pose a direct threat to human health.

Vegetables ingest metals by absorbing them from contaminated soil as well from deposits on different parts of the vegetable exposed to the metal from polluted environments. Many heavy metals act as biological poisons even at parts per billion (ppb) levels.

The distribution of heavy metals (such as iron, copper, manganese, lead, chromium and zinc) in leaves, stems and roots of fluted pumpkin (*Telfeiria occidentalis*) were investigated at three different street roads in Cross River State of Nigeria (Edem et al., 2009). The streets were Afokang, Anantigha and Eneobong. The result showed that, the concentrations of Fe, Mn, Pb and Cr were highest in the leaves.

Also, Afokang Street with the heaviest vehicular traffic out of the three streets recorded the highest concentration of Pb in the leaves of the plants. This may be attributed to the high level of exhaust emissions from vehicles plying the road.

Ademoronti (1986) in his findings on a study carried out in Benin, Nigeria, showed that lead deposits on bark of trees were found to vary according to traffic volumes; areas of high traffic volume recorded higher concentrations of lead. Further studies have revealed that lead does not readily accumulate in the fruiting part of vegetables and crops (e.g., corn, beans, tomatoes, apples and berries); a higher concentration of lead is most likely to be found in leafy vegetables and on the surface of roots crops.

According to Ademoronti (1986), plants accumulate minerals essential for their growth from the environment and also accumulate metals such as cadmium (Cd) and chromium (Cr) which have no known direct benefit to the plants (Brook and Robinson 1989). From Ademoroti's (1995) findings, cadmium is present in low concentrations in vegetable leaves, entering the human body through diet. The mechanism of trace metals' movement within plants was investigated by Walsh (1971). He found that most metals become chelated by a relatively simple agent in xylem sap.

The iron content of normal plant tissue varies with the plant species, but it is usually between the range of 20 - 200mg/kg dry matter (Walsh, 1971). The cobalt content of a normal plant is usually within the range of 0.01 – 1.00mg/kg dry matter (Walsh, 1971). Lead is toxic to crops at concentration range of 3 -20 ppm depending on the plant species; and to animals at a concentration of 1mg/day (Bowen, 1979). Zinc is an essential mineral involved in catalytic functions and is important for both man and plants health and growth (Jeffery, 1992). The zinc content of normal plants tissues varies according to plant species, but it is usually within the range of 5 – 300mg/kg dry matter (Walsh, 1971).

202 Agricultural Chemistry

**2. Heavy metal**

(Purseglove, 1977)

This is a member of an ill-defined subset of an element that exhibit metallic properties, which would mainly include the transition metals, some metalloids, lanthanides and actinides. Many different definitions have been proposed - some based on density, some based on atomic number or atomic weight and some on chemical properties or toxicity

The primary anthropogenic sources of heavy metals are point sources such as mines, foundries, smelters, coal-burning power plants, and other sources such as combustion of wastes, and vehicle emissions. Some investigations carried out have shown that heavy metal

Vegetables ingest metals by absorbing them from contaminated soil as well from deposits on different parts of the vegetable exposed to the metal from polluted environments. Many

The distribution of heavy metals (such as iron, copper, manganese, lead, chromium and zinc) in leaves, stems and roots of fluted pumpkin (*Telfeiria occidentalis*) were investigated at three different street roads in Cross River State of Nigeria (Edem et al., 2009). The streets were Afokang, Anantigha and Eneobong. The result showed that, the concentrations of Fe,

Also, Afokang Street with the heaviest vehicular traffic out of the three streets recorded the highest concentration of Pb in the leaves of the plants. This may be attributed to the high

Ademoronti (1986) in his findings on a study carried out in Benin, Nigeria, showed that lead deposits on bark of trees were found to vary according to traffic volumes; areas of high traffic volume recorded higher concentrations of lead. Further studies have revealed that lead does not readily accumulate in the fruiting part of vegetables and crops (e.g., corn, beans, tomatoes, apples and berries); a higher concentration of lead is most likely to be

According to Ademoronti (1986), plants accumulate minerals essential for their growth from the environment and also accumulate metals such as cadmium (Cd) and chromium (Cr) which have no known direct benefit to the plants (Brook and Robinson 1989). From Ademoroti's (1995) findings, cadmium is present in low concentrations in vegetable leaves, entering the human body through diet. The mechanism of trace metals' movement within plants was investigated by Walsh (1971). He found that most metals become chelated by a

The iron content of normal plant tissue varies with the plant species, but it is usually between the range of 20 - 200mg/kg dry matter (Walsh, 1971). The cobalt content of a normal plant is usually within the range of 0.01 – 1.00mg/kg dry matter (Walsh, 1971). Lead is toxic to crops at concentration range of 3 -20 ppm depending on the plant species; and to animals at a concentration of 1mg/day (Bowen, 1979). Zinc is an essential mineral involved in

accumulation in vegetables may pose a direct threat to human health.

Mn, Pb and Cr were highest in the leaves.

relatively simple agent in xylem sap.

level of exhaust emissions from vehicles plying the road.

found in leafy vegetables and on the surface of roots crops.

heavy metals act as biological poisons even at parts per billion (ppb) levels.

Generally vegetables appear to have the highest and lowest amount of heavy metals accumulated in their leaves and seed respectively e.g. beans, peppers, tomatoes, melons and peas show very low intake of heavy metals in their seed. Plant intake of heavy metals varies with soil PH. A study by Echem (2010) on cassava cultivated on oil polluted soil showed that soil contaminated with heavy metals cause contamination of foodstuffs.

Heavy metals are associated with myriad adverse health effects, including allergic reaction, nephrotoxicity, and cancer. Humans are often exposed to heavy metals in various ways mainly through the inhalation of metals in the workplace or polluted neighbourhoods, or through the ingestion of food that contains high levels of heavy metals or paint chips that contain lead Ifon, (1977).

The three heavy metals commonly cited as being of the greatest public health concern are cadmium, lead and mercury. There is no biological need for any of these three heavy metals. Exposure to cadmium can result in emphysema, renal failure, cardiovascular disease and perhaps cancer. The primary adverse health effect from exposure to lead is neurological impairment (particularly in children). Other adverse health effects associated with lead include sterility in males and nephrotoxicity.

Heavy metals have been reported to play positive and negative roles in human life (Slavesk et al., 1998; Divrikli et al., 2003; Dundar and Saglam, 2004). Some heavy metals like cadmium, lead and mercury are major contaminants of food supply and may be considered as very harmful to the environment since they do not biodegrade while others like iron, zinc and copper are essential for biochemical reactions in the body (Zaidi et al., 2005). Jarup (2003) and Sathawera et al., (2004) have reported that, most heavy metals are not biodegradable, have long biological half-lives and have the potential for accumulation in the different body organs leading to unwanted side effects. There is a strong link between micronutrient of plants, animals and humans, and the uptake and impact of contaminants in these organisms (Yuzbas, et al., 2003; Yaman et al., 2005).

Research findings by Divrikli et al. (2006) had shown that the concentration of essential elements in plants is conditional; it is affected by the characteristics of the soil and the ability of plants to selectively accumulate some metals. Sources of heavy metals for plants include rainfall in atmospheric polluted areas, heavy traffic as a result of high discharge of exhaust effluents- indiscriminate disposal of oil or fossil fuels by road side mechanics, - plant protection chemicals and fertilizers which could be absorbed through leaf blades (Kovacheva et al., 2000; Lozak et al., 2002; Sobukola et al., 2006).

The aim of this research is to ascertain the level of heavy metals ingested by bitter leaf grown along heavy traffic routes. It is a well established fact that diesel, gasoline, lubricants, vehicle parts such as carburettors among others, contain heavy metals. The routes chosen for this study record the highest traffic density for heavy duty vehicles, lorries, buses and cars in Rivers State; this is due to the presence of Onne Sea Port, Eleme and Port Harcourt Refineries, Eleme Petrochemicals among others on one hand, and the movement of goods and persons between Aba and Port Harcourt on the other. On these routes, it is common to see vehicles under- going various types of repairs, mechanic workshops and heavy exhaust emissions, and these invariably become the primary source of pollution to the road side soils. Symptoms associated with acute oral zinc dose are vascular shock, vomiting, diarrhoea, pancreatitis and damage of hepatic parenchyma. Consequently, crop plants growing on heavy metal contaminated medium can accumulate high concentrations of trace metals causing serious health risks to consumers.

Heavy Metal Content in Bitter Leaf (*Vernonia amygdalina*)

was dissolved in 5ml of 20% hydrochloric acid and the solution was carefully transferred into a 100ml volumetric flask. The solution was filtered using Whatman No 1 filter paper (Umoren and Onianwa, 2005) into a 50ml volumetric flask and made up to the mark with distilled deionised water. The samples were taken to the Shimadzu atomic absorption

The determination of heavy metal (Fe, Zn, Cr, Pb and Cd) content of the sample solution was carried out in accordance with the procedure of the AOAC (1984) on dry samples.

The results of the heavy metal analysis of the bitter leaf samples are shown in table 1.

Sample Location Fe Pb Cr Cd Zn Bitter Leaf PH-Aba Road 2.96 0.220 0.030 ND 0.890 Bitter leaf Akpajo-Eleme Road 3.43 0.405 0.052 ND 1.08 Bitter leaf Refinary-Akpajo Road 3.27 0.350 0.041 ND 1.12 Mean 3.22 0.325 0.042 ND 1.03 Bitter leaf Kina Gbara Street 2.21 0.156 0.024 ND 0.84

The results in table 1 show that the concentrations (mg/kg) of the heavy metals fall within the following range: iron (Fe) is 2.21 to 3.43, lead (Pb) is 0.156 to 0.405, chromium (Cr) is 0.024 to 0.052, zinc (Zn) is 0.840 to 1.12, while Cadmium (Cd) was not detected in any of the

spectrophotometer (model 6650) for aspiration.

**Table 1.** Concentration (mg/kg) of heavy metal in bitter leaf

**Figure 1.** Bar Chart for the concentration of heavy metals

**4. Results and discussion**

ND = not detected.

locations.

Grown Along Heavy Traffic Routes in Port Harcourt 205

#### **3. Hypothesis**

HO: There is significant difference in the mean concentration of heavy metals in bitter leaf cultivated along heavy traffic route from the ones cultivated away from the routes.

HA: There is no significant difference in the mean concentration of heavy metals in bitter leaf cultivated along heavy traffic routes from the ones cultivated away from the routes.

#### **3.1. Materials and methods**

The materials used for this study include among others bitter leaf, stainless steel knife, laboratory grinder, polythene bags, desiccator, analytical balance, platinum crucible, muffle furnace, hydrochloric acid, volumetric flask, distilled water and atomic absorption spectrophotometer.

#### **3.2. Study area**

The research was carried out in three different heavy traffic vehicular routes in Rivers State. These routes are: Eleme Junction – Aba Road, Eleme Junction – Akpajo Road and Akpajo – Refinery Junction. The control location was Kina Gbara Street in Bori, Khana Local Government Area.

#### **3.3. Sample collection and preparation**

The bitter leaf samples were obtained from the four stated locations. The bitter leaf were harvested from two different sites per location; and then put into separate polythene bags and labelled accordingly. They were then taken immediately to the laboratory for preparation and analysis.

The bitter leaf (*Vernonia amygdalina)* samples were washed with tap water and thoroughly rinsed with distilled water, then dried in an oven at 105oC. They were then pulverized to fine powder using a laboratory grinder. The fine powder was put into polythene bags and preserved in the desiccator. 3.0g of each sample was accurately weighed into clean platinum crucible and ashed at 450-500oC, then cooled to room temperature in the desiccator. The ash was dissolved in 5ml of 20% hydrochloric acid and the solution was carefully transferred into a 100ml volumetric flask. The solution was filtered using Whatman No 1 filter paper (Umoren and Onianwa, 2005) into a 50ml volumetric flask and made up to the mark with distilled deionised water. The samples were taken to the Shimadzu atomic absorption spectrophotometer (model 6650) for aspiration.

The determination of heavy metal (Fe, Zn, Cr, Pb and Cd) content of the sample solution was carried out in accordance with the procedure of the AOAC (1984) on dry samples.

#### **4. Results and discussion**

The results of the heavy metal analysis of the bitter leaf samples are shown in table 1.

ND = not detected.

204 Agricultural Chemistry

**3. Hypothesis**

**3.1. Materials and methods**

spectrophotometer.

**3.2. Study area**

Government Area.

preparation and analysis.

**3.3. Sample collection and preparation**

routes.

metals causing serious health risks to consumers.

in Rivers State; this is due to the presence of Onne Sea Port, Eleme and Port Harcourt Refineries, Eleme Petrochemicals among others on one hand, and the movement of goods and persons between Aba and Port Harcourt on the other. On these routes, it is common to see vehicles under- going various types of repairs, mechanic workshops and heavy exhaust emissions, and these invariably become the primary source of pollution to the road side soils. Symptoms associated with acute oral zinc dose are vascular shock, vomiting, diarrhoea, pancreatitis and damage of hepatic parenchyma. Consequently, crop plants growing on heavy metal contaminated medium can accumulate high concentrations of trace

HO: There is significant difference in the mean concentration of heavy metals in bitter leaf cultivated along heavy traffic route from the ones cultivated away from the routes.

HA: There is no significant difference in the mean concentration of heavy metals in bitter leaf cultivated along heavy traffic routes from the ones cultivated away from the

The materials used for this study include among others bitter leaf, stainless steel knife, laboratory grinder, polythene bags, desiccator, analytical balance, platinum crucible, muffle furnace, hydrochloric acid, volumetric flask, distilled water and atomic absorption

The research was carried out in three different heavy traffic vehicular routes in Rivers State. These routes are: Eleme Junction – Aba Road, Eleme Junction – Akpajo Road and Akpajo – Refinery Junction. The control location was Kina Gbara Street in Bori, Khana Local

The bitter leaf samples were obtained from the four stated locations. The bitter leaf were harvested from two different sites per location; and then put into separate polythene bags and labelled accordingly. They were then taken immediately to the laboratory for

The bitter leaf (*Vernonia amygdalina)* samples were washed with tap water and thoroughly rinsed with distilled water, then dried in an oven at 105oC. They were then pulverized to fine powder using a laboratory grinder. The fine powder was put into polythene bags and preserved in the desiccator. 3.0g of each sample was accurately weighed into clean platinum crucible and ashed at 450-500oC, then cooled to room temperature in the desiccator. The ash **Table 1.** Concentration (mg/kg) of heavy metal in bitter leaf

The results in table 1 show that the concentrations (mg/kg) of the heavy metals fall within the following range: iron (Fe) is 2.21 to 3.43, lead (Pb) is 0.156 to 0.405, chromium (Cr) is 0.024 to 0.052, zinc (Zn) is 0.840 to 1.12, while Cadmium (Cd) was not detected in any of the locations.

**Figure 1.** Bar Chart for the concentration of heavy metals

The order of concentration of each heavy metal in the bitter leaf harvested from all the studied locations is: iron (Fe) in bitter leaf harvested along Akpajo - Eleme Junction Road soil > Refinery - Akpajo Junction Road soil > Port Harcourt – Aba Road soil > Kina Gbara Street soil (Bori); lead (Pb) in bitter leaf harvested along Akpajo Road soil – Eleme Junction Road soil > Refinery – Akpajo Junction Road soil > Port Harcourt – Aba Road soil > Kina Gbara street soil (Bori); chromium (Cr) in bitter leaf harvested along Akpajo-Eleme Junction Road soil > Refinery – Akpajo Junction Road soil > Port Harcourt Aba Road soil > Kina Gbara street(Bori).

Heavy Metal Content in Bitter Leaf (*Vernonia amygdalina*)

Sample ID Fe Pb Cr Zn Total

B. leaf (Ph Aba Road 2.96 (2.860) 0.220 (0.289) 0.030 (0.036) 0.890 (0.915) 4.10 B" Akpajo Etc. 3.43 (3.465) 0.405 (0.350) 0.052 (0.044) 1.08 (0.582) 4.967

**Total 9.66 0.975 0.123 3.09 13.848**

= 0.0035 + 0.0004 + 0.0013 + 0.0165 + 0.0086 + 0.0005 + 0.001+ 0.0015 + 0.0000 + 0.0007 +

Decision: since X2 = 0.4601 is less than the critical value – 0.872, the null hypothesis (HO) is

Therefore, there is significant difference between B leaf (Bori) control and X2 = 0.4601 at 1%

3.27 (3.335) 0.350 (0.337) 0.041 (0.042) 1.12 (1.067) 4.781

By using chi-square x2 , i.e.,

Where VT = Vertical Total HT = Horizontal Total GT = Ground Total.

The expected value,

B" Refinery and Akpajo Road

To find the chi-square,

At 1% significant level i.e., 0.01

d.f = (n-1) (m-1) = (3–1) (4–1)

Degree of freedom = d.f = 6

= (2) (3) = 6

accepted and the alternative hypothesis (HI); is rejected.

0.4261 + 0.0026

X2 = 0.4601.

1 – 0.01 = 0.99

X2 0.99, 6 = 0.872

significant level.

, ,

, ,

, ,

= .

, =0.350,

Grown Along Heavy Traffic Routes in Port Harcourt 207

Zinc (Zn) in Refinery – Akpajo Junction Road soil > Akpajo – Eleme Junction Road soil > Port Harcourt – Aba Road soil > Kina Gbara street soil (Bori). The results further reveal that; the high concentration of iron (Fe), lead (Pb), chromium (Cr) and Zinc (Zn) found in the leaves of the bitter leaf may be due to the high levels of exhaust emission from the vehicles plying these roads, (Edem et al., 2009).This view is further supported by the relative lower concentrations of the heavy metals found in the control sample collected in Bori. The level of concentration of Fe in the control sample in addition to the low concentration of toxic heavy metals makes it suitable for human consumption (Ifon, 1977). The high concentration of iron in bitter leaf might be attributed to the nature of the soil and sometimes by the presence of some bacterial that depends on Fe2+ for source of energy.

The results of the study indicate that the bitter leaf harvested along Akpajo – Eleme Junction Road had the highest concentration of iron (Fe), lead (Pb) and chromium (Cr), compared to the one from Bori (control), while Refinery-Akpajo Junction Road had the second highest concentration of iron (Fe) lead (Pb) and chromium (Cr). The highest concentration of zinc (Zn) was also recorded along this route.

The findings of this study agree with the results of Edem et al. (2009) on levels of heavy metals in pumpkin leaves harvested in streets with heavy vehicular traffic in Cross River State and the report on the investigation of the deposit of lead on the bark of trees planted in areas of high traffic volume in Benin carried out by Ademoronti (1986).

The mean concentration of Pb (0.325) and Cr (0.041) in the sampled bitter leaf were above the WHO tolerable limit of 0.005 – 0.1 and 0.005 – 0.01 respectively. The bioaccumulation of these heavy metals has adverse health implications to man, especially in children and pregnant women (Dupler, 2001).

The high concentration of Fe reported in this study is in conformity with that published by Hart et al. (2005) on concentrations of trace metals (Pb, Fe, Cu and Zn) in crops harvested in some oil prospecting locations in Rivers State. The likely reason given for this high value of iron is the participation of green vegetables in the synthesis of ferrodoxin. However, the mean concentration of Fe (3.22) falls within the acceptable range (1.0 – 4.0mg/100g) as published by Platt (1980). The mean concentration of Zn (1.03) is also within the acceptable limit. However, from WHO (1984) report, excessive intake of Fe and Zn is capable of causing vomiting, dehydration, electrolytic imbalance and lack of muscular co-ordination.

By using chi-square x2 , i.e.,

The expected value,

Where VT = Vertical Total

 HT = Horizontal Total GT = Ground Total.

, ,

206 Agricultural Chemistry

Gbara street(Bori).

The order of concentration of each heavy metal in the bitter leaf harvested from all the studied locations is: iron (Fe) in bitter leaf harvested along Akpajo - Eleme Junction Road soil > Refinery - Akpajo Junction Road soil > Port Harcourt – Aba Road soil > Kina Gbara Street soil (Bori); lead (Pb) in bitter leaf harvested along Akpajo Road soil – Eleme Junction Road soil > Refinery – Akpajo Junction Road soil > Port Harcourt – Aba Road soil > Kina Gbara street soil (Bori); chromium (Cr) in bitter leaf harvested along Akpajo-Eleme Junction Road soil > Refinery – Akpajo Junction Road soil > Port Harcourt Aba Road soil > Kina

Zinc (Zn) in Refinery – Akpajo Junction Road soil > Akpajo – Eleme Junction Road soil > Port Harcourt – Aba Road soil > Kina Gbara street soil (Bori). The results further reveal that; the high concentration of iron (Fe), lead (Pb), chromium (Cr) and Zinc (Zn) found in the leaves of the bitter leaf may be due to the high levels of exhaust emission from the vehicles plying these roads, (Edem et al., 2009).This view is further supported by the relative lower concentrations of the heavy metals found in the control sample collected in Bori. The level of concentration of Fe in the control sample in addition to the low concentration of toxic heavy metals makes it suitable for human consumption (Ifon, 1977). The high concentration of iron in bitter leaf might be attributed to the nature of the soil and sometimes by the presence of

The results of the study indicate that the bitter leaf harvested along Akpajo – Eleme Junction Road had the highest concentration of iron (Fe), lead (Pb) and chromium (Cr), compared to the one from Bori (control), while Refinery-Akpajo Junction Road had the second highest concentration of iron (Fe) lead (Pb) and chromium (Cr). The highest concentration of zinc

The findings of this study agree with the results of Edem et al. (2009) on levels of heavy metals in pumpkin leaves harvested in streets with heavy vehicular traffic in Cross River State and the report on the investigation of the deposit of lead on the bark of trees planted in

The mean concentration of Pb (0.325) and Cr (0.041) in the sampled bitter leaf were above the WHO tolerable limit of 0.005 – 0.1 and 0.005 – 0.01 respectively. The bioaccumulation of these heavy metals has adverse health implications to man, especially in children and

The high concentration of Fe reported in this study is in conformity with that published by Hart et al. (2005) on concentrations of trace metals (Pb, Fe, Cu and Zn) in crops harvested in some oil prospecting locations in Rivers State. The likely reason given for this high value of iron is the participation of green vegetables in the synthesis of ferrodoxin. However, the mean concentration of Fe (3.22) falls within the acceptable range (1.0 – 4.0mg/100g) as published by Platt (1980). The mean concentration of Zn (1.03) is also within the acceptable limit. However, from WHO (1984) report, excessive intake of Fe and Zn is capable of causing

vomiting, dehydration, electrolytic imbalance and lack of muscular co-ordination.

areas of high traffic volume in Benin carried out by Ademoronti (1986).

some bacterial that depends on Fe2+ for source of energy.

(Zn) was also recorded along this route.

pregnant women (Dupler, 2001).

, =0.350,

, ,

, ,

To find the chi-square,

=

.

= 0.0035 + 0.0004 + 0.0013 + 0.0165 + 0.0086 + 0.0005 + 0.001+ 0.0015 + 0.0000 + 0.0007 + 0.4261 + 0.0026

X2 = 0.4601.

At 1% significant level i.e., 0.01

1 – 0.01 = 0.99

d.f = (n-1) (m-1) = (3–1) (4–1)

= (2) (3) = 6

Degree of freedom = d.f = 6

X2 0.99, 6 = 0.872

Decision: since X2 = 0.4601 is less than the critical value – 0.872, the null hypothesis (HO) is accepted and the alternative hypothesis (HI); is rejected.

Therefore, there is significant difference between B leaf (Bori) control and X2 = 0.4601 at 1% significant level.

#### **5. Conclusion**

This study has shown that the mean concentration of heavy metals in bitter leaf harvested along heavy traffic route soil is significant compared with the one harvested away from these routes. The observed common practice of cultivating vegetables in the soil along heavy traffic routes in Port Harcourt will in the long run endanger consumers' health since the ingested heavy metals bioaccumulates in the human body. Consequently, there is a need for all the relevant government and non- governmental agencies to bring this to the knowledge of the general public.

Heavy Metal Content in Bitter Leaf (*Vernonia amygdalina*)

Hart A.D., Oboh C.A., Barimalaa I.S. and Sokari T.G. (2005). Concentrations of trace metals (lead, iron, copper and zinc) in crops harvested in some oil prospecting locations in Rivers State, Nigeria. African Journal of Floor and Nutritional Sciences

Ifon, E.T. (1977). The nutrient composition of some Nigerian leafy green vegetables and physiological availability of their iron content. Ph.D thesis, Department of Biochemistry

Kovacheva P., Djingova R., Kuleff I. (2000). On the representative sampling of plants for

Lozak A., Sotyk K., Ostapezuk P., Fijalek Z. (2002). Determination of selected trace elements

Platt B.S. (1980). Tables of Representative Values of Foods Commonly Used in Tropical Countries. Medical Research Council. Special Report Series. No 302 (Revised Edition of

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Jarup L. (2003) Hazards of heavy metals contamination. Br. Med. Bull 68:167-182 Jeffery, P.K. (1992). Environmental toxicology, Edward Arnold Ltd. London. 68-78.

Volume 5 no. 2

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SRS 253) London: Her Majesty's Stationery Office.

Grown Along Heavy Traffic Routes in Port Harcourt 209

#### **Author details**

Ogbonda G. Echem

*Department of Science Laboratory Technology, Rivers State Polytechnic, Bori, Nigeria*

L. G. Kabari

*Department of Science Laboratory Technology, Rivers State Polytechnic, Bori, Nigeria Member, IEEE, Department of Computer Science Rivers State Polytechnic, Bori, Nigeria*

#### **6. References**

**5. Conclusion**

of the general public.

**Author details**

Ogbonda G. Echem

L. G. Kabari

**6. References**

Ibadan

Ibadan

pp.213-273.

21:60-63

This study has shown that the mean concentration of heavy metals in bitter leaf harvested along heavy traffic route soil is significant compared with the one harvested away from these routes. The observed common practice of cultivating vegetables in the soil along heavy traffic routes in Port Harcourt will in the long run endanger consumers' health since the ingested heavy metals bioaccumulates in the human body. Consequently, there is a need for all the relevant government and non- governmental agencies to bring this to the knowledge

*Department of Science Laboratory Technology, Rivers State Polytechnic, Bori, Nigeria*

*Department of Science Laboratory Technology, Rivers State Polytechnic, Bori, Nigeria Member, IEEE, Department of Computer Science Rivers State Polytechnic, Bori, Nigeria*

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Zaidi M. I., Asrar A., Mansoor A., Faroogui M.A. (2005) . The heavy metal concentration along roadsides of Quetta and its effects on public health J. Appl. Sci.5(4): 708-711.

*Edited by Margarita Stoytcheva and Roumen Zlatev*

The present book is a collection of ten original research articles and reports, associated with selected topics in agricultural chemistry. The discussed issues are organized in four sections: Classification and labeling of active substances in plant protection products, Environmental and stress plant physiology and behavior, Antimicrobial and antioxidant potential of plant extracts, and Pollutants analysis and effects. The information provided in this book should be of interest for academic researchers and for agriculturalists.

Agricultural Chemistry

Agricultural Chemistry

*Edited by Margarita Stoytcheva and Roumen Zlatev*

Photo by Pogonici / iStock


**5.3 TSH receptor and autoantibodies**

Long-acting thyroid stimulator (LATS) was found among patients with Graves' hyperthyroidism [86] and it is proved to be an immunoglobulin which inhibited the binding of radiolabeled thyroid stimulating hormone to thyroid membranes due to the presence of antibodies to the TSH receptor (TSHR-Ab) [87].


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# **The Characteristics of Phytoremediation of Soil and Leachate Polluted by Landfills**

Reyhan Erdogan and Zeynep Zaimoglu

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/61105

#### **Abstract**

Current landfill regulations provide for the responsible management of solid waste and a safer alternative to the outdated practices of open or illegal dumping. Aside from imparting aesthetic value, natural or planted vegetation on landfill sites has an important role in erosion control and removal of contaminants, and may also be used in leaching treatment. The use of leachate for the irrigation of landfill vegetation reduces its harmful effects, and the reuse of water aids in water conservation. The aim of this study was to search for ways to use leachate water from solid waste landfill sites for irrigation of plant species that normally grow in the wild. The study focuses on the plant species *Alcea rosea* (hollyhock), *Cynodon dactylon* (Bermuda grass) and *Melilotus officinalis* (yellow melilot). Over the 2-year study period, plants were irrigated with tap and leachate water under drought conditions. Wild plant diversity was identified, and the landfill was rehabilitated with various plant species. After the experiment, populations of *Escherichia coli*, total coliforms and fecal coliform bacteria in soil samples were analyzed. We observed that the use of leachate water for cultivation of different kinds of plants affected the density of total and fecal coliforms in the soil.

**Keywords:** Landfill, Leachate water, Remediation, Coliform bacteria

# **1. Introduction**

With the rapid increase in population and urbanization, solid waste landfills are emerg‐ ing as a major problematic urban infrastructure. Urban solid waste can be stored both underground and aboveground, but each creates environmental and human health risks.

© 2015 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Those involved in solid waste management continue to search for ways to reduce these risks. Landfills are required to use synthetic and/or soil liners of site-specific thickness and hydraulic conductivity as well as various other safeguards to isolate the waste from nearby groundwater, air and soil [1].

Waste landfill management is an important concern, as negative effects are often caused by discontinuation of traditional management practices. The adverse effects on flora and fauna resulting from changes inland use patterns have been described by landscape ecologists throughout Europe [2], and have been reported by several authors for Mediterranean land‐ scapes such as the montado and agro-silvopastoral systems in Portugal [3], the Tuscany region of Italy [4], the mountainous landscapes in northern Italy [5], and the shrub and woodland areas in Israel and other Mediterranean countries [6]. Aside from imparting aesthetic value, natural or planted vegetation on a landfill has an important role in erosion control and removal of contaminants, and may also be used in leaching treatment. Although phytoremediation of various contaminants has been investigated, the practical application of this technology to the remediation and rehabilitation of municipal solid waste landfill sites has not been sufficiently studied [7].

Areas of bare soil, where vegetation is not present, are open to erosion. The soil of landfills is not generally suitable for growing plants, and protective soil cover is needed. Additionally, planting will have no effect on erosion in the short term without the selection of optimal plants. In our previous study, we examined species best suited for this purpose and found that certain plants could be used for remediation of cover soil [7]. Other studies have found approximately 120 plant species, consisting of trees, shrubs, and grasses, that are appropriate for establishing plant cover in different types of vegetative amelioration [8, 9]. One of the most common plant mixtures used in rehabilitation is grasses and legumes. Grasses are regarded as most appro‐ priate for protection from soil erosion, while legumes grow rapidly, particularly in soils with a low concentration of nitrogen [8, 10, 11].

Leachate is a major issue in landfills and surrounding areas, as it is very harmful to the environment. Leachate interacts with soil and ground and surface waters, and contains high degrees of organic and inorganic pollutants. It is the longest-lasting emission from landfills [12], and therefore the liquid waste causes considerable pollution [13]. One of the most promising methods for mitigating these effects is the use of leachate water for irrigation of vegetation planted on landfills. Research has shown that this technique enables the reuse of polluted water as a result of the remediating effects of plants and microorganisms. The landfill cover soil was irrigated with leachate for maintaining appropriate moisture content for methane oxidation reaction. Municipal solid waste compost was found to be an effective landfill cover material for controlling landfill gas emissions, exhibiting the highest methane oxidation rate [14]. Soil is a habitat for a great number of organisms, but at the same time, it is perhaps the most endangered component of our environment, and can be altered by the different pollutants arising from human activity [15, 16]. Prevention of soil pollution and its harmful effects, however, requires some basic knowledge of the soil characteristics. Soil has a very complex structure and exhibits greatly different properties among various regions [17].

Trace elements such as metals in contaminated soil also have negative impacts on human health and the environment, and thus their removal is often required. Metals can be stabilized by soil amendments to increase metal adsorption or alter their chemical form [18]. There have been few experiments comparing different in situ remediation treatments under similar environmental conditions or investigating whether all soil components or properties (e.g., microbes, soil fauna, plants, soil retention and colloid stability) are similarly protected. As part of the EU FP7 Greenland project (reference number 266124), we compared the impact of novel soil amendments and their combinations with traditional materials with regard to metal solubility and the response of plants, soil organisms and microbial activity [19]. Soil metal bioavailability is often cited as a limiting factor in phytoextraction (or phytomining). Bacterial metabolites such as organic acids, siderophores, and bio surfactants have been shown to mobilize metals, and the use of microbial inoculants to improve metal extraction has been proposed by several authors [20].

Plants, in combination with their associated micro flora, have a prominent role in remediating soils contaminated with organic pollutants such as petroleum hydrocarbons. Several plantassociated bacteria have the capacity to degrade hydrocarbons, promote plant growth and alleviate plant stress. In many cases, this is due to the fact that inoculant strains may not adequately interact with or colonize plants used for phytoremediation and/or cannot compete with the resident micro flora under certain environmental conditions. However, colonization and the competitive ability of inoculants trains is generally rarely addressed, despite the fact that an understanding of the efficiency of inoculation is essential [21].

In cases when phytoremediation is successfully performed, target pollutants play roles such as enhancing bioavailability by altering the flora or microbial community structure, either through stimulation of existing microbial degraders or through the introduction and estab‐ lishment of new organisms [22]. For example, surface flow wetlands have proved to be successful in removing selenium (Se) from wastewater. Researchers also reported that constructed wetlands can remove up to 90 % of Se contained in the inflow of oil refinery waste water and up to 80 % from agricultural irrigation drainage [23].

As a result of manmade activities, large areas of soil are contaminated with multiple pollutants, and these high concentrations of pollutants have toxic effects on the environment. Plant microorganism-based technologies can supply a strategy for soil remediation and for the restoration of soil functionality after treatment [24].Soil conditions such as pH, the composition of organic matter and vegetation, and supplements influence soil micronutrient dynamics [25]. Soils may become polluted with high concentrations of heavy metals that are naturally produced by the melting of ore or artificially produced by industrial activities [26, 27].Among pollutants, heavy metals exceeding specific thresholds have been the subject of particular attention because of their long-standing toxicity. Their mobility in the ecosystem and transition through food chains are key issues in environment research [28–33]. Organic amendments may influence soil properties for years after application, as only a fraction of the organic material may be initially degraded or become available to plants and soil microorganisms [34, 35].

Issues with heavy metal contamination at landfill sites have recently been noted. Landfill remediation is generally performed by restoration of the site through the creation of a low hill planted with plants indigenous to the area. The aim of the current study was to search for ways to use leachate water from solid waste landfill sites for irrigation of plant species that grow wild under normal climate conditions. The study focuses on the plant species *Alcea rosea* (hollyhock)*, Cynodon dactylon* (Bermuda grass) and *Melilotus officinalis* (yellow melilot). During the 2 years of the study, plants were irrigated with tap and leachate water under drought conditions. The wild plant species were determined in the hollyhock, Bermuda grass and yellow melilot parcels. After the experiment, populations of *E. coli*, total coliforms and fecal coliform bacteria in the soil samples were analyzed. Results showed that using leachate water to cultivate various types of plants affected total and fecal coliform populations in the soil.

# **2. Characteristics of the Adana-Sofulu landfill and the plants used for remediation**

The Adana-Sofulu landfill is the first major landfill in Turkey at which scientifical planting rehabilitation has been conducted. The population of Adanais 2,026,319, and Adana Province is the political and economic center of the Cukurova region. Field experiments were conducted between 37°03'12"N and 37°03'12.1"N and between35°23'34.3"E and 35°23'35"E [8] (Figure 1).

The city of Adana is in the Mediterranean climate region, and during this study,plants were irrigated with leachate water and tap water during the drought season. Figure 2 shows temperatures and rainfall amounts, including the drought season, for the city of Adana [36]. The irrigation was conducted from May to September.

Until recently, there has been no urgent need for planting of landfill areas. Landfills were generally transformed into small copses within 20 years after the planting of populous species that would grow to a depth of 30 cm from the soil surface. In later years, however, toxic degradation products of waste compounds have created issues that have brought about the need for new planting strategies [37].

Typical plant remediation methods in landfill areas include "grassing" and "grassing and reforestation". In the grassing method, 20-cm class I and II soil layers are laid on wasteland, and a mixture of *Lolium*, *Dactylis*, *Poa, Agrostis*, *Cynodon*, *Trifolium*, *Medicago* and *Vicia* seeds are planted there. This method of rehabilitation of landfill areas is very common in England. In grassing landfill areas, trees are just an ornamental element. With the grassing and refor‐ estation method, it is important to determine the timing of landfill closures. With old landfill sites, there are no serious problems with the timing of planting. Soil that has been incubated in a fermentation process is laid on the waste site at a thickness of 30 cm, and grassing then begins with the seeding of *Lolium*, *Dactylis*, *Trifolium* and *Poa.* In this process, the grassy vegetation is first laid on the soil layer. After the vegetation has been established, the *Popu‐ lus* and *Salix* species are planted to begin reforestation [38, 39].

The Characteristics of Phytoremediation of Soil and Leachate Polluted by Landfills http://dx.doi.org/10.5772/61105 231

**Figure 1.** Map showing location of the Sofulu landfill [8]

**Figure 2.** Drought index of study area [36]

In the Sofulu landfill rehabilitation study, three plant species—*Alcea rosea* (hollyhock)*, Cynodon dactylon* (Bermuda grass) and *Melilotus officinalis* (yellow melilot)—were selected on the basis of their ecological characteristics including area of spread, the need for soil nutrient sand their tolerance to extreme temperatures. These plants require few nutrients. Each plant species has a different seed weight. To obtain equal numbers of seeds, we followed the recommended weights for plants. Accordingly, 80 g of *A. rosea*, 600 g of *C. dactylon* and 3 g of *M. officinalis* seeds were sown on each parcel. Figure 3 shows photographs of the three plant species [8].

*A. rosea* flower (hollyhock) (Original) *A.rosea* plant group in the plot (Original)

*M. officinalis* flower (yellow melilot)(Original) *M. officinalis* plant group in the plot (Original)

*C. dactylon* (Bermuda grass) (Original) *C. dactylon* covering in the plot (Original)

# **3. Change in vegetation at the planted plots**

The experimental design of the study was based on the plot applications, and the study was conducted at three independent plots. Treatment equipment was constructed in the Sofulu waste landfill, which was covered with 30 cm of soil in the B soil horizon. Experimental plots 6 m2 (2 m × 3 m) in size were prepared, and three types of plants (*A. rose, C. dactylon* and *M. officinalis*) were each planted on 6 plots. The climate in the site is typical of the Mediterranean, and is characterized by a hot, dry period between May and September. The mean annual rainfall in the area is 647 mm, which occurs in the winter and spring seasons, and therefore irrigation is necessary in the summer for any plant growth [8].

The plants in the experiments were irrigated with either tap water or leachate wastewa‐ ter under drought conditions. Nine plots were not irrigated and were used as controls in order to evaluate the effects of irrigation. The leachate waste water was taken from the basin of the Sofulu landfill site [8]. Figure 4 shows the changes in vegetation at the plots of south waste landfill over 2 years. Few plants were observed in the spring after plant seeds were sown in February. However, growth of *A. rosea* was observed, and the flower bloomed in autumn of that year; *M. officinalis* and *C. dactylon* also grew in the spring of the following year. Moreover, the mixed vegetation of the three plants was found in the next autumn. Subsequently, 41wild plant species were also seen in the experiment parcels. The names of the species are given in Table 1. In this study, gramines (*Bromus arvensis, Lolium temulentum* and *Polypogon monspeliensis)* grew in high numbers in the plot irrigated with tap and leachate wastewater.

Figure 5 shows high numbers of *L. temulentum* and *Silybum marianum* in the plots. In contrast, legumes (*Lathyrus annuus, Psoralea bituminosa, Trifolium campestre* and *Trifolium speciosum*) were not able to propagate insufficient numbers. A study by Arambatsiz et al. [11] was able to achieve significant rehabilitation after mining activities with gramines and legumes, and another study[40] reported that gramines and legumes were grown for the rehabilitation of a degraded study area.

We were able to obtain a sufficient number of wild plants on the landfill and achieve a green landscape when the field was irrigated with leachate water during the drought season. Therefore, the planting of appropriate plants and the use of irrigation by leachate water appears to be an efficient means of rapid landfill remediation as well as removal of pollutants contained in leachate water.

As shown in Table 1, the highest number of wild plant species, 21, was in the *M. officinalis* plots. The *C. dactylon* plots had 17 and *A. rosea* plots had 16 wild plant species with landfill leachate irrigation. *C. dactylon* is so dominant plant species [41, 42], Figure 6 shows that it did not permit to sprawl the wild plants in some plots. *M. officinalis* was also dominant in the spring in some plots.

The first autumn in the study area The second autumn in the study area

**Figure 4.** Change in vegetation at the plots of the Sofulu landfill

*Lolium temulentum* in the plot *Silybum marianum* in the plot

**Figure 5.** High-number species in the plots

*C. dactylon* plot *M. officinalis* plot

 **Figure 6.** Some of the dominant species in the plots

**Table 1.** Wild plant species grown in plots irrigated with leachate wastewater and tap water [8, 36]

The dominance of plants belonging to four families, viz., Poaceae, Asteraceae, Polygonaceae and Chenopodiaceae, while other species were found to occur only sporadically in the Stockholm, Malmo and Helsingborg landfills of Sweden [43].At the Kodungaiyur and Perungudi dumping grounds in Chennai, India, the dominant plant species recorded were *Acalypha indica*, *Solanum lycopersicum, Parthenium hysterophorus*, *C. dactylon* and *Cucurbita maxima* [44].

The wild plant species in the Sofulu landfill experimental plots are shown in Figure 7.

The Characteristics of Phytoremediation of Soil and Leachate Polluted by Landfills http://dx.doi.org/10.5772/61105 237

*Xanthium spinosum Amaranthus deflexus Heliotropium europium*

**Figure 7.** The wild plants in the Sofulu landfill experimental plots

# **4. Microbial soil analysis**

Over the2-yearstudy period, plants were irrigated with tap water and landfill leachate water during drought conditions (May to September). The landfill leachate water was taken from the collection basin of the Adana Sofulu landfill site. Tables 2 and 3 show the physiochemical, biological and microbial characteristics of landfill leachate water used for the irrigation.

There are three groups of coliform bacteria. Each is an indicator of water and soil quality, and each has a different level of risk. Total coliforms are a large collection of different kinds of bacteria. Fecal coliforms are types of total coliforms that exist in feces, and *Escherichia coli* is a subgroup of fecal coliforms. Total coliform bacteria are common in the environment (soil or vegetation) and are generally harmless [45].

Landfill leachate water showed high concentrations of nitrogen, phosphate and minerals at pH values of 7.9–8.4, and therefore, chemical oxygen demand (COD) and biochemical oxygen demand (BOD) were high, suggesting that landfill irrigation with leachate water may enhance microbial concentration. Microbial density at the plots was thus examined, and these charac‐ teristics were analyzed according to standard methods[46].

*COD* chemical oxygen demand, *BOD* biochemical oxygen demand

**Table 2.** Landfill leachate water properties [8, 36]

Soil samples were collected from three locations within each treatment parcel and mixed. The soil was used for analysis of fecal total coliforms and fecal coliform bacteria. Each soil sample was mixed with sterile water or physiological saline and divided into three subsamples. A membrane filter technique was used for all bacteriological assays [47]. Microorganisms containing thermo tolerant fecal coliforms transferred onto the membrane were incubated on fecal coliform (M-FC, Difco Laboratories, Inc.) agar medium for 24 h at 44.5 °C, and the number of colonies was counted. In the case of *E.coli*, the cells transferred onto the membrane were incubated in M-FC agar medium containing 4-methylumbelliferyl-β-D-glucuronide for 4 h at

**Table 3.** Landfill leachate water microbial properties [8, 36]

35 °C. The colonies generating blue fluorescence by exposure to a longwave UV light (366 nm) were counted as *E. coli* cells. The minimum indication level was approximately 30colonyforming units (CFU)/ml, whereas the maximum cutoff level was 300 CFU/ml.

The mean values were compared between groups using one-way ANOVA. A significance level of *P*<0.05 was used throughout the study. The SPSS Version 10.0 software program [48] was used for these statistical analyses. Duncan's multiple range test was applied to bacterial count data.

### **5. Effect of landfill and leachate water on microorganisms**

Soil is generally a favorable habitat for the proliferation of microorganisms, with microcolonies developing around soil particles [49]. Bacteria comprise the most abundant group of microorganisms in the soil (3.0× 106 to 5.0× 108 per gram of soil), followed by the actinomycetes (1.0× 106 to 2.0× 107 ), fungi (5.0× 103 to 9.0× 106 ), yeast (1.0× 103 to 1.0 ×106 ), algae and protozoa (1.0× 103 to 5.0× 105 ), and nematodes (50–200 per gram of soil),with wide differences in the relative proportions of individual bacteria genera found in particular soils[50, 51]. In this study, the total coliform bacteria count varied from 2.1 ×105 to 7.4 ×105 in landfill soil.

The number of extant bacterial species is thought to range from 3 × 104 to 3 × 106 [52], of which only a small fraction have been cultured and identified [53,54]. Mayr et al. reported that due to differences in cultivability among soils, the number of cultivable bacteria per ml inoculums ranged from 0.6 ×103 (forest soil) to 7 × 103 (agricultural soil),with significant variability [55]. *E. coli* and thermo tolerant coliform bacteria are widely used as indicators of soil characteristics. However, many microorganisms, including ente rococci, coliphages, and sulfite-reducing clostridial spores, have been suggested as microbial indicators of fecal pollution [56], and anaerobic digestion processes, if operated properly, have long been known to successfully reduce the number of pathogens and indicator organisms [57,58]. In a study by Zhang et al. investigating microorganism concentration in raw sewage, the bacterial indicators total and fecal coliforms were enumerated. The average concentrations of total and fecal coliforms were 2.5 ×107 CFU/100 ml and 9.6×106 CFU/100 ml, respectively [59].

In the last a few years, researchers have reported higher fecal coliform populations, on a dry solids basis, in centrifugally dewatered bio solids compared to digester effluents [60–67]. Therefore, landfill irrigation by leachate water may represent a key process for landfill remediation and rehabilitation.

Tables 4 and 5 show the microbial density at the plots. As shown in Table 4, the density of fecal and total coliforms increased with the use of leachate water, with almost equal amounts between landfill and clean areas, which suggests that leachate water irrigation is an effective method of landfill remediation. The effects of the plants were also examined, as shown in Table 5. The types of plants affected the amount of fecal coliforms, with the highest concentration in the area planted with *A. rosea* (8.6 ×103 ).

Data analyzed using Duncan's multiple range test. *b* maximum value, *ab* intermediate value, *a* minimum value. Alpha = 0.05

**Table 4.** Changes in fecal coliform bacteria and total coliform density in soil for different factors

Data analyzed using Duncan's multiple range test. *b* maximum value; *ab* intermediate value, *a* minimum value. Alpha = 0.05

**Table 5.** Changes in fecal coliform bacterial density in the soil with different plant species

# **6. Conclusions**

Solid waste landfill sites pose a significant hazard to natural life, and mitigation of these harmful effects has posed a major challenge. This study proved that the use of leachate wastewater for plant breeding on a landfill in drought weather conditions caused a change in microbial activity in the landfill cover soil. If leachate is used for irrigation, the site should be safely enclosed by fencing, given the negative microbial effect on human health.

Landfill rehabilitation has a positive effect on the landscape. In today's world, waste reduction is critically important, as is the need to ensure that people are able to live in a healthy and beautiful environment. The transformation of brownfield areas into healthy green landscapes using recycled wastewater is an area of research that should be a primary focus of scientists.

This paper examines reasons for considering the use of plant remediation for microbial pollution in landfills. These areas offer the potential for improving biodiversity, and turning these problem areas into opportunities requires the selection of the appropriate plants and the most effective technique. The re-vegetation of landfills can increase biodiversity as well as reduce microbial pollution. This article provides an example of such a strategy for landfills in the Mediterranean climate zone.

### **Author details**

Reyhan Erdogan1\* and Zeynep Zaimoglu2

\*Address all correspondence to<EMAIL_ADDRESS>
1 Akdeniz University, Agricultural Faculty, Department of Landscape Architecture, Antalya, Turkey

2 Cukurova University, Faculty of Engineering and Architecture, Department of Environmental Engineering, Adana, Turkey

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