unsmoked cigarette filters (no tobacco). the results of the study showed that for the ld50of both marine topsmelt (atherinops affinis) and freshwater fathead minnow (pimephales promelas), smoked cigarette filters + tobacco are more toxic than smoked cigarette filters, but both are severely more toxic than unsmoked cigarette filters. ld50 of cigarette filters to marine life (cigarette per liter) cigarette typemarine topsmeltfathead minnow smoked cigarette filter (smoked filter + tobacco)1.01.0 smoked cigarette filters (no tobacco)1.84.3 unsmoked cigarette filters (no tobacco)5.113.5 other health concerns toxic chemicals are not the only human health concern to take into considerations; the others are cellulose acetate and carbon particles that are breathed in while smoking. these particles are suspected of causing lung damage. the next health concern is that of plants. under certain growing conditions, plants on average grow taller and have longer roots than those exposed to cigarette filters in the soil. a connection exists between cigarette filters introduced to soil and the depletion of some soil nutrients over time. another health concern to the environment is not only the toxic carcinogens that are harmful to the wildlife, but also the filters themselves pose an ingestion risk to wildlife that may presume filter litter as food. the last major health concern to make note of for marine life is the toxicity that deep marine topsmelt and fathead minnow pose to their predators. this could lead to toxin build-up (bioaccumulation) in the food chain and have long reaching negative effects. smoldering cigarette filters have also been blamed for triggering fires from residential areas to major wildfires and bushfires which has caused major property damage and also death as well as disruption to services by triggering alarms and warning systems. degradation once in the environment, cellulose acetate can go through biodegradation and photodegradation. several factors go into determining the rate of both degradation process. this variance in rate and resistance to biodegradation in many conditions is a factor in littering and environmental damage. discarded newport cigarettes packs found in olneyville, rhode island - 2008 biodegradation chemical hydrolysis of cellulose acetate the first step in the biodegradation of cellulose acetate is the deactylation of the acetate from the polymer chain (which is the opposite of acetylation). an acetate is a negative ion with the chemical formula of c2h3o2−. deacetylation can be performed by either chemical hydrolysis or acetylesterase. chemical hydrolysis is the cleavage of a chemical bond by addition of water. in the reaction, water (h2o) reacts with the acetic ester functional group attached the cellulose polymer chain and forms an alcohol and acetate. the alcohol is simply the cellulose polymer chain with the acetate replaced with an alcohol group. the second reaction is exactly the same as chemical hydrolysis with the exception of the use of an acetylesterase enzyme. the enzyme, found in most plants, catalyzes the chemical reaction shown below. acetic ester + h2o ⇌ alcohol + acetate in the case of the enzymatic reaction, the two substrates (reactants) are again acetic ester and h2o, the two products of the reaction are alcohol and acetate. this reaction is exactly the same as the chemical hydrolysis. both of these products are perfectly fine in the environment. once the acetate group is removed from the cellulose chain, the polymer can be readily degraded by cellulase, which is another enzyme found in fungi, bacteria, and protozoans. cellulases break down the cellulose molecule into monosaccharides ("simple sugars") such as beta-glucose, or shorter polysaccharides and oligosaccharides. the chemical structure change of cellulose into glucosethese simple sugars are not harmful to the environment and are in fact are a useful product for many plants and animals. the breakdown of cellulose is of interest in the field of biofuel. due to the conditions that affect the process, large variation in the degradation time of cellulose acetate occurs. factors in biodegradation the duration of the biodegradation process is cited as taking as little as one month to as long as 15 years or more, depending on the environmental conditions. the major factor that affects the biodegradation duration is the availability of acetylesterase and cellulase enzymes. without these enzymes, biodegradation only occurs through chemical hydrolysis and stops there. temperature is another major factor, if the organisms that contain the enzymes are too cold to grow, then biodegradation is severely hindered. availability of oxygen in the environment also affects the degradation. cellulose acetate is degraded within 2–3 weeks under aerobic assay systems of in vitro enrichment cultivation techniques and an activated sludge wastewater treatment system. it is degraded within 14 weeks under anaerobic conditions of incubation with special cultures of fungi. ideal conditions were used for the degradation (i.e. right temperature, and available organisms to provide the enzymes). thus, filters last longer in places with low oxygen concentration (ex. swamps and bogs). overall, the biodegraditon process of cellulose acetate is not an instantaneous process. photodegradation the other process of degradation is photodegradation, which is when a molecular bond is broken by the absorption of photon radiation (i.e. light). due to cellulose acetate carbonyl groups, the molecule naturally absorbs light at 260 nm, but it contains some impurities which can absorb light. these impurities are known to absorb light in the far uv light region (< 280 nm). the atmosphere filters radiation from the sun and allows radiation of > 300 nm only to reach the surface. thus, the primary photodegradation of cellulose acetate is considered insignificant to the total degradation process, since cellulose acetate and its impurities absorb light at shorter wavelengths. research is focused on the secondary mechanisms of photodegradation of cellulose acetate to help make up for some of the limitations of biodegradation. the secondary mechanisms would be the addition of a compound to the filters that would be able to absorb natural light and use it to start the degradation process. the main two areas of research are in photocatalytic oxidation and photosensitized degradation. photocatalytic oxidation uses a species that absorbs radiation and creates hydroxyl radicals that react with the filters and start the breakdown. photosensitized degradation, though, uses a species that absorbs radiation and transfers the energy to the cellulose acetate to start the degradation process. both processes use other species that absorbed light > 300 nm to start the degradation of cellulose acetate. solution and remediation projects a cigarette disposal canister, encouraging the public to dispose of their cigarettes properly several options are available to help reduce the environmental effects of cigarette butts. proper disposal into receptacles leads to decreased numbers found in the environment and their effect on the environment. another method is making fines and penalties for littering filters; many governments have sanctioned stiff penalties for littering of cigarette filters; for example, washington imposes a penalty of $1,025 for littering cigarette filters. another option is developing better biodegradable filters; much of this work relies heavily on the research in the secondary mechanism for photodegradation as stated above, but a new research group has developed an acid tablet that goes inside the filters, and once wet enough, releases acid that speeds up the degradation to around two weeks. the research is still only in test phase and the hope is soon it will go into production. the next option is using cigarette packs with a compartment in which to discard cigarette butts, implementing monetary deposits on filters, increasing the availability of butt receptacles, and expanding public education. it may even be possible to ban the sale of filtered cigarettes altogether on the basis of their adverse environmental effects. recent research has been put into finding ways to use the filter waste to develop a desired product. one research group in south korea has developed a simple one-step process that converts the cellulose acetate in discarded cigarette filters into a high-performing material that could be integrated into computers, handheld devices, electrical vehicles, and wind turbines to store energy. these materials have demonstrated superior performance as compared to commercially available carbon, grapheme, and carbon nanotubes. the product is showing high promise as a green alternative for the waste problem. consumption a woolworths supermarket cigarette counter in new south wales, australia: in january 2011, australia prohibited the display of cigarettes in retail outlets countrywide. cigarette salespeople in jakarta, indonesia smoking has become less popular, but is still a large public health problem globally. worldwide, smoking rates fell from 41% in 1980 to 31% in 2012, although the actual number of smokers increased because of population growth. in 2017, 5.4 trillion cigarettes were produced globally, and were smoked by almost 1 billion people. smoking rates have leveled off or declined in most countries, but is increasing in some low- and middle-income countries. the significant reductions in smoking rates in the united states, united kingdom, australia, brazil, and other countries that implemented strong tobacco control programs have been offset by the increasing consumption in low income countries, especially china. the chinese market now consumes more cigarettes than all other low- and middle-income countries combined. other regions are increasingly playing larger roles in the growing global smoking epidemic. the who eastern mediterranean region (emro) now has the highest growth rate in the cigarette market, with more than a one-third increase in cigarette consumption since 2000. due to its recent dynamic economic development and continued population growth, africa presents the greatest risk in terms of future growth in tobacco use. within countries, patterns of cigarette consumption also can vary widely. for example, in many of the countries where few women smoke, smoking rates are often high in males (e.g., in asia). by contrast, in most developed countries, female smoking rates are typically only a few percentage points below those of males. in many high and middle income countries lower socioeconomic status is a strong predictor of smoking. smoking rates in the united states have dropped by more than half from 1965 to 2016, falling from 42% to 15.5% of us adults. australia is cutting their overall smoking consumption faster than most of the developed world, in part due to landmark plain packaging act, which standardized the appearance of cigarette packs. other countries have considered similar measures. in new zealand, a bill has been presented to parliament in which the government's associate health minister said "takes away the last means of promoting tobacco as a desirable product." smoking prevalence by sex (ages 15 or older, 2016) percent smoking region men women africa18%2% americas21%12% eastern mediterranean34%2% europe38%21% southeast asia32%2% western pacific46%3% leading consumers of cigarettes (2016) countrypopulation(millions)cigarettes consumed(billions)cigarettes consumed(per capita) china1,3862,3512,043 indonesia2643161,675 russia1452782,295 united states3272661,017 japan1271741,583 lights main article: lights (cigarette type) some cigarettes are marketed as "lights", "milds", or "low-tar". these cigarettes were historically marketed as being less harmful, but there is no research showing that they are any less harmful. the filter design is one of the main differences between light and regular cigarettes, although not all cigarettes contain perforated holes in the filter. in some light cigarettes, the filter is perforated with small holes that theoretically diffuse the tobacco smoke with clean air. in regular cigarettes, the filter does not include these perforations. in ultralight cigarettes, the filter's perforations are larger. the majority of major cigarette manufacturers offer a light, low-tar, or mild cigarette brand. due to recent u.s. legislation prohibiting the use of these descriptors, tobacco manufacturers are turning to color-coding to allow consumers to differentiate between regular and light brands. research shows that smoking "light" or "low-tar" cigarettes is just as harmful as smoking other cigarettes. notable cigarette brands 520 555 amber leaf army club ardath basic bel air benson & hedges berkeley camel capri chesterfield davidoff dunhill djarum doral du maurier eclipse embassy eve export a fatima fortuna gauloises gitanes gold flake golden virginia gold leaf kyriazi freres kent kool lambert and butler l&m lark lucky strike marlboro mayfair merit mild seven more nat sherman natural american spirit newport next nil old gold pall mall parliament perilly's peter stuyvesant peter jackson philip morris player's prince raleigh ronhill salem sampoerna senior service smokin joes sobranie sovereign sterling surya tareyton vantage viceroy virginia slims west woodbine windsor blue winfield winston smoking cessation main article: smoking cessation smoking cessation (quitting smoking) is the process of discontinuing the practice of tobacco smoking. quitting can be difficult for many smokers due to the addictive nature of nicotine.: 2300–2301 the addiction begins when nicotine acts on nicotinic