Polychlorinated biphenyls as a health hazard

PCBs (polychlorinated biphenyls; there are dozens of trade names for them) are some of the most toxic and environmentally persistent chemicals ever created. PCBs don’t break down, can remain for long periods cycling between air, water and soil, travel long distances and can be taken up into the bodies of small organisms and fish and concentrated up the food chain. The list of potential health problems for humans and animals is legion, including cancer and reproductive and immune system harms.

PCBs get into the environment by incomplete burning, leaching from the soil, vapourizing from paints, coatings and plastics, by illegal dumping or by accident.

A broad spectrum of adverse health effects have been reported in people occupationally exposed to polychlorinated biphenyls (PCBs). These effects may be generally explained by the induction or the inhibition of the activity of a large number of enzymes which upset quantitatively normal biological processes. Carcinogenicity of PCBs has been shown in animals, experimentally exposed.

The prevalence of the adverse health effects increases with exposure to higher concentrations of PCBs in the working environment. Reported effects are: changes in the skin and mucous membranes; swelling of the eyelids, burning of the eye, and excessive eye discharge; burning sensation and oedema of face and hands; simple erythematous eruptions with pruritus; acute eczematous contact dermatitis (vesiculo-erythematous eruptions); chloracne (an extremely refractory form of acne); hyperpigmentation of skin and mucous membranes (palpebral conjunctiva, gingiva); discoloration of finger nails; and thickening of the skin. Irritation of the upper respiratory tract is frequently seen. A decrease in forced vital capacity, without radiological changes, was reported in a relatively high percentage of the workers exposed in a capacitor factory. Digestive symptoms such as abdominal pain, anorexia, nausea, vomiting, jaundice, with rare cases of coma and death, may occur. At autopsy, acute yellow atrophy of the liver has been sporadically reported in lethal cases. Neurological symptoms such as headache, dizziness, depression, nervousness, etc, and other symptoms such as fatigue, loss of weight, loss of libido and muscle and joint pains has been found in various percentages of exposed people.

The US EPA estimates that the class of PCBs constitutes more than 200 individual substances.

Prior to 1976, when they were banned in the USA, PCBs were used in products ranging from electrical transformers to light bulbs to paint, glue and cardboard. They were heralded for their ability to prevent electrical fires. The 1500 million pounds previously manufactured worked their way into many lakes--particularly the Great Lakes and the lakes of the northeastern U.S. PCBs became more concentrated as they worked their way up the food chain: it was estimated, for instance, that fish-eating water birds in Lake Michigan can have PCB levels in their flesh 25 million times greater than the level of the surrounding lake water; marine mammals have a rising quantity of PCBs in their blubber.

Monsanto (and Monsanto-related entities) is facing hundreds of lawsuits on behalf of people who claim their exposure to PCBs caused non-Hodgkin lymphoma.

In 2002, Monsanto was found guilty of decades of "outrageous acts of pollution" in the town of Anniston, Alabama, where it dumped PCBs into the local river and secretly buried the toxic chemical in a landfill. Internal documents revealed Monsanto had full knowledge of the severity of the pollution problem it caused for at least three decades, and decided to ignore it.

The City of Seattle filed a lawsuit against Monsanto for PCB pollution in the Duwamish River also making the river's fish too contaminated to eat. The city alleged that Monsanto knew all along that PCBs were toxic but continued to market them anyway; that the company intentionally concealed the certainty of global contamination in order to maximize profits. Other US cities that have filed lawsuits against Monsanto include San Diego (for polluting the Coronado Bay with PCBs), San Diego, San Jose, Oakland and Berkeley, California and Spokane, Washington.

In 2020, the global chemical giant Bayer (purchaser of Monsanto's chemical division) agreed to pay $650 million to settle the claims of 2,500 cities, counties and ports for cleanup of contamination from PCBs.

In 2022, a court in Washington, USA awarded 13 adults and children $275 million for neurological damage caused by PCBs produced by Monsanto; in total there are 200 students, parents and teachers filing suit for physical damage.

During a conference in Washington in 1998, aimed at restricting the production of toxic chemicals and persistent organic pollutants, Russian delegates confessed that Russia would not be able to comply with the pact as Russia still produces and uses PCBs, for example in the manufacture of transformers used on their power grid. Russia had previously assured European governments that new production of these chemicals had ceased. Negotiators accepted that Russia did not have the money to convert and allowed production to continue until 2005 and postponed the destruction of the last stocks until 2020. The fact that Russia produces, uses and perhaps exports PCBs which may be more dangerous to more people than plutonium has attracted little attention.