company to clean up cancer-causing pcbs from los angeles county waterways and storm sewer pipelines. the lawsuit calls for monsanto to pay for cleanup of pcbs from dozens of waterways, including the la river, san gabriel river and the dominguez watershed. in june 2020, bayer agreed to pay $650 million to settle local lawsuits related to monsanto's pollution of public waters in various areas of the united states with pcbs. history old power transformers are a major source of pcbs. even units not originally filled with pcb may be contaminated, since pcb and oil mix freely and any given transformer may have been refilled from hoses or tanks also used with pcbs. in 1865, the first "pcb-like" chemical was discovered, and was found to be a byproduct of coal tar. years later in 1876, german chemist oscar döbner (doebner) synthesized the first pcb in a laboratory. since then, large amounts of pcbs were released into the environment, to the extent that there are even measurable amounts of pcbs in feathers of birds currently held in museums before the production of pcbs peaked. in 1935, monsanto chemical company (now solutia inc) took over commercial production of pcbs from swann chemical company which had begun in 1929. pcbs, originally termed "chlorinated diphenyls", were commercially produced as mixtures of isomers at different degrees of chlorination. the electric industry used pcbs as a non-flammable replacement for mineral oil to cool and insulate industrial transformers and capacitors. pcbs were also commonly used as heat stabilizer in cables and electronic components to enhance the heat and fire resistance of pvc. in the 1930s, the toxicity associated with pcbs and other chlorinated hydrocarbons, including polychlorinated naphthalenes, was recognized because of a variety of industrial incidents. between 1936 and 1937, there were several medical cases and papers released on the possible link between pcbs and its detrimental health effects. in 1936 a u.s. public health service official described the wife and child of a worker from the monsanto industrial chemical company who exhibited blackheads and pustules on their skin. the official attributed these symptoms to contact with the worker's clothing after he returned from work. in 1937, a conference about the hazards was organized at harvard school of public health, and a number of publications referring to the toxicity of various chlorinated hydrocarbons were published before 1940. in 1947, robert brown reminded chemists that arochlors were "objectionably toxic": "thus the maximum permissible concentration for an 8-hr. day is 1 mg. per cu.m. of air. they also produce a serious and disfiguring dermatitis". in 1954, kanegafuchi chemical co. ltd. (kaneka corporation) first produced pcbs, and continued until 1972. through the 1960s monsanto chemical company knew increasingly more about pcbs' harmful effects on humans and the environment, per internal leaked documents released in 2002, yet pcb manufacture and use continued with few restraints until the 1970s. in 1966, pcbs were determined by swedish chemist sören jensen to be an environmental contaminant. jensen, according to a 1994 article in sierra, named chemicals pcbs, which previously, had simply been called "phenols" or referred to by various trade names, such as aroclor, kanechlor, pyrenol, chlorinol and others. in 1972, pcb production plants existed in austria, west germany, france, the uk, italy, japan, spain, the ussr and the us. in the early 1970s, ward b. stone of the new york state department of environmental conservation (nysdec) first published his findings that pcbs were leaking from transformers and had contaminated the soil at the bottom of utility poles. there have been allegations that industrial bio-test laboratories engaged in data falsification in testing relating to pcbs. in 2003, monsanto and solutia inc., a monsanto corporate spinoff, reached a us$700 million settlement with the residents of west anniston, alabama who had been affected by the manufacturing and dumping of pcbs. in a trial lasting six weeks, the jury found that "monsanto had engaged in outrageous behavior, and held the corporations and its corporate successors liable on all six counts it considered – including negligence, nuisance, wantonness and suppression of the truth." existing products containing pcbs which are "totally enclosed uses" such as insulating fluids in transformers and capacitors, vacuum pump fluids, and hydraulic fluid, are allowed to remain in use in the us. the public, legal, and scientific concerns about pcbs arose from research indicating they are likely carcinogens having the potential to adversely impact the environment and, therefore, undesirable as commercial products. despite active research spanning five decades, extensive regulatory actions, and an effective ban on their production since the 1970s, pcbs still persist in the environment and remain a focus of attention. pollution due to pcbs belgium in 1999, the dioxin affair occurred when 50 kg of pcb transformer oils were added to a stock of recycled fat used for the production of 500 tonnes of animal feed, eventually affecting around 2,500 farms in several countries. the name dioxin affair was coined from early misdiagnosis of dioxins as the primary contaminants, when in fact they turned out to be a relatively small part of the contamination caused by thermal reactions of pcbs. the pcb congener pattern suggested the contamination was from a mixture of aroclor 1260 and 1254. over 9 million chickens, and 60,000 pigs were destroyed because of the contamination. the extent of human health effects has been debated, in part because of the use of differing risk assessment methods. one group predicted increased cancer rates, and increased rates of neurological problems in those exposed as neonates. a second study suggested carcinogenic effects were unlikely and that the primary risk would be associated with developmental effects due to exposure in pregnancy and neonates. two businessmen who knowingly sold the contaminated feed ingredient received two-year suspended sentences for their role in the crisis. italy the italian company caffaro, located in brescia, specialized in producing pcbs from 1938 to 1984, following the acquisition of the exclusive rights to use the patent in italy from monsanto. the pollution resulting from this factory and the case of anniston, in the us, are the largest known cases in the world of pcb contamination in water and soil, in terms of the amount of toxic substance dispersed, size of the area contaminated, number of people involved and duration of production. the values reported by the local health authority (asl) of brescia since 1999 are 5,000 times above the limits set by ministerial decree 471/1999 (levels for residential areas, 0.001 mg/kg). as a result of this and other investigations, in june 2001, a complaint of an environmental disaster was presented to the public prosecutor's office of brescia. research on the adult population of brescia showed that residents of some urban areas, former workers of the plant, and consumers of contaminated food, have pcb levels in their bodies that are in many cases 10–20 times higher than reference values in comparable general populations. pcbs entered the human food supply by animals grazing on contaminated pastures near the factory, especially in local veal mostly eaten by farmers' families. the exposed population showed an elevated risk of non-hodgkin lymphoma, but not for other specific cancers. japan in 1968, a mixture of dioxins and pcbs got into rice bran oil produced in northern kyushu. contaminated cooking oil sickened more than 1,860 people. the symptoms were called yushō disease. in okinawa, high levels of pcb contamination in soil on kadena air base were reported in 1987 at thousands of parts per million, some of the highest levels found in any pollution site in the world. republic of ireland main article: 2008 irish pork crisis in december 2008, a number of irish news sources reported testing had revealed "extremely high" levels of dioxins, by toxic equivalent, in pork products, ranging from 80 to 200 times the eu's upper safe limit of 1.5 pg who-teqdfp/μg i.e. 0.12 to 0.3 parts per billion. brendan smith, the minister for agriculture, fisheries and food, stated the pork contamination was caused by pcb-contaminated feed that was used on 9 of ireland's 400 pig farms, and only one feed supplier was involved. smith added that 38 beef farms also used the same contaminated feed, but those farms were quickly isolated and no contaminated beef entered the food chain. while the contamination was limited to just 9 pig farms, the irish government requested the immediate withdrawal and disposal of all pork-containing products produced in ireland and purchased since september 1, 2008. this request for withdrawal of pork products was confirmed in a press release by the food safety authority of ireland on december 6. it is thought that the incident resulted from the contamination of fuel oil used in a drying burner at a single feed processor, with pcbs. the resulting combustion produced a highly toxic mixture of pcbs, dioxins and furans, which was included in the feed produced and subsequently fed to a large number of pigs. kenya in kenya, a number of cases have been reported in the 2010s of thieves selling transformer oil, stolen from electric transformers, to the operators of roadside food stalls for use in deep frying. when used for frying, it is reported that transformer oil lasts much longer than regular cooking oil. the downside of this misuse of the transformer oil is the threat to the health of the consumers, due to the presence of pcbs. slovakia the chemical plant chemko in strážske (east slovakia) was an important producer of polychlorinated biphenyls for the former communist bloc (comecon) until 1984. chemko contaminated a large part of east slovakia, especially the sediments of the laborec river and reservoir zemplínska šírava. slovenia between 1962 and 1983, the iskra kondenzatorji company in semič (white carniola, southeast slovenia) manufactured capacitors using pcbs. due to the wastewater and improperly disposed waste products, the area (including the krupa and lahinja rivers) became highly contaminated with pcbs. the pollution was discovered in 1983, when the krupa river was meant to become a water supply source. the area was sanitized then, but the soil and water are still highly polluted. traces of pcbs were found in food (eggs, cow milk, walnuts) and krupa is still the most pcb-polluted river in the world. spain and portugal several cetacean species have very high mean blubber pcb concentrations likely to cause population declines and suppress population recovery. striped dolphins, bottlenose dolphins and orcas were found to have mean levels that markedly exceeded all known marine mammal pcb toxicity thresholds. the western mediterranean sea and the south-west iberian peninsula were identified as "hotspots". united kingdom monsanto manufactured pcbs at its chemical plant in newport, south wales, until the mid- to late-1970s. during this period, waste matter, including pcbs, from the newport site was dumped at a disused quarry near groes-faen, west of cardiff, and penhros landfill site from where it continues to be released in waste water discharges. united states monsanto was the only company that manufactured pcbs in the us. its production was entirely halted in 1977. (kimbrough, 1987, 1995) on november 25, 2020, u.s. district judge fernando m. olguin rejected a proposed $650 million settlement from bayer, the company which acquired monsanto in 2018, and allowed monsanto-related lawsuits involving pcb to proceed. alabama pcbs originating from monsanto chemical company in anniston, alabama, were dumped into snow creek, which then spread to choccolocco creek, then logan martin lake. in the early 2000s, class action lawsuits were settled by local land owners, including those on logan martin lake, and lay reservoir (downstream on the coosa river), for the pcb pollution. donald stewart, former senator from alabama, first learned of the concerns of hundreds of west anniston residents after representing a church which had been approached about selling its property by monsanto. stewart went on to be the pioneer and lead attorney in the first and majority of cases against monsanto and focused on residents in the immediate area known to be most polluted. other attorneys later joined in to file suits for those outside the main immediate area around the plant; one of these was the late johnnie cochran. in 2007, the highest pollution levels remained concentrated in snow and choccolocco creeks. concentrations in fish have declined and continue to decline over time; sediment disturbance, however, can resuspend the pcbs from the sediment back into the water column and food web. connecticut in new haven, the decommissioned