The industry could be producing more cancer-causing PCB chemicals today than at any other time in history, despite their production being banned more than 40 years ago.
PCBs, or polychlorinated biphenyls, are man-made substances that were used as coolants and lubricants in electrical equipment until they were banned due to their link to health problems and because they do not break down easily in the environment.
They are known to cause cancer in animals and damage the immune, reproductive, nervous and endocrine systems. They also have the potential to be carcinogenic in humans and exposure to them has been linked to acne-like skin conditions in adults and neurobehavioral and immunological changes in children.
Research by the Guardian and Watershed Investigations shows that PCBs are produced as by-products of chemical reactions, meaning small amounts of them are present in many chemicals used today.
“This is mind-boggling considering that PCB production was banned over 40 years ago and we should be eliminating them under the Stockholm Convention,” said environmental forensic scientist Dr Dave Megson of Manchester Metropolitan University, who conducted the research performed. study.
“When we take into account the volumes of these chemicals and the small levels of PCBs in them, this amounts to a huge number – about 45,000 tons per year in the US alone.” During the peak of commercial production in the 1970s, about 39,000 tons were produced annually, the study said.
“Most people associate this accidental production of PCBs with paints and pigments, but our research shows it is much broader than that,” says Megson. Chlorinated solvents, used in chemical production, are a major source, according to the study.
“PCBs currently go undetected in many studies because the specific PCBs accidentally produced differ from those deliberately produced in the commercial mixtures of more than 50 years ago.”
The study says these types of byproduct PCBs are not measured in many existing monitoring programs and could pose a “growing, uncontrolled risk to the environment and human health.” It suggests they should be classified as “a pollutant of concern” and addressed urgently as all PCBs are considered toxic, not just older PCBs from commercial mixtures.
Lee Bell from the International Chemicals NGO Network, who is also a member of the Stockholm Convention PCB Expert Group, said: “Not much effort has been made to regulate the unintentional production of PCBs from chemical production. In the case of intentional PCB production, parties to the convention have a deadline to eliminate all stockpiles of old PCBs by 2028. They are woefully behind on this task and approximately 80% of PCB stockpiles have yet to be destroyed.
“The study’s assumption that approximately 43,000 tons of PCBs could have been legally produced in the US in 2019 may well be the case despite the uncertainties. This would surpass Monsanto’s 1970 peak US production of 39,000 tons. On a global scale, current unintentional PCB production could be much higher and needs to be urgently investigated.”
Bell says stricter limits should be placed on emissions of waste and byproduct PCBs into water. “It is disappointing that hundreds of millions of dollars are being spent to destroy obsolete PCBs while regulators allow unintentional PCB contamination to spread virtually unabated.”
PCBs have been found in high concentrations in marine mammals and have long been a concern for Dr Francesca Ginley of the Marine Conservation Society. “PCBs are persistent chemicals… they linger for decades, accumulate and bioaccumulate in the environment marine mammals.
“We have seen the impact of PCBs on the UK killer whale population, which is heading towards complete collapse within the next hundred years, consistent with severe PCB pollution. A killer whale off the west coast of Scotland was found dead in 2016 after becoming entangled in fishing nets. A post-mortem examination found that the levels of PCBs in her tissues were 100 times higher than levels known to affect the health of marine mammals,” Ginley said.
Research by the Zoological Society of London in collaboration with the University of Glasgow last year found that killer whales stranded in Britain exceed the toxic threshold for PCBs by 30 times. It has warned that the chemicals “threaten to wipe out orcas”.
The production of PCBs was banned in the US in 1979 and in Britain in 1981, and efforts to restrict their use in electrical equipment in Britain continue. Sources of historical contamination from commercially manufactured PCBs include landfills and materials in buildings.
A spokesperson for Defra did not comment on the production of PCBs as by-products, but said: “We have committed to eliminating the use of PCBs by 2025 in our environmental improvement plan, working with industry to register and dispose of all equipment to use. containing these chemicals.
“We have also consulted on proposals to change PCB regulations to ensure we meet our obligations (under the international Stockholm Convention) and to provide clarity for industry and business. Our consultation response and next steps will be published in due course.”
The U.S. Environmental Protection Agency (EPA) said its “regulations allow unintentionally generated PCBs at low, defined concentrations and under certain conditions. Although no monitoring program exists, facilities that generate or import unintentionally generated PCBs are required to report this activity to the EPA and maintain records of the PCBs, including the levels of PCBs they produced and released.
The U.S. EPA said it could not comment on Megson’s findings, but did say that when the regulations went into effect, their information was that “less than 10,000 pounds (4,989 kg) of unintentionally generated PCBs are estimated to enter products annually, and of less than £1,000 of that amount is likely to be released into the environment each year.”
Last month, the EPA received a petition from the Washington State Department of Ecology regarding the issue of unintentionally generated PCBs. It requests that the EPA “initiate regulations to protect public health from PCBs in consumer products.” The EPA must grant or deny the request no later than April 3, 2024.
Ginley said: “If PCBs continue to be released, the problem will only get worse. They don’t cause short-term problems; they impact entire generations of animals. It’s not just about killer whales; PCBs have been linked to higher mortality from infectious diseases and lower testicular weight in British porpoises. We need to learn from the ongoing damage caused by PCBs and apply it to other persistent chemicals, and not keep making the same mistakes.”
