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Roula Khalaf, Editor of the FT, selects her favourite stories in this weekly newsletter.
The writer is a science commentator
The 2019 film Dark Waters, starring Mark Ruffalo, helped to thrust “forever chemicals” into the public consciousness. It dramatised a legal case brought against DuPont for contaminating water supplies in West Virginia, alleged to have contributed to cattle deaths and cancer clusters among locals. The case ended in 2017 with a $671mn settlement for about 3,500 plaintiffs.
Concern over the chemicals — more properly known as perfluoroalkyl and polyfluoroalkyl substances, or PFAS — has snowballed of late. Thousands of US lawsuits targeting major chemical companies have been filed and agencies globally are tightening regulation. The lawsuits have drawn comparisons with past “toxic torts” regarding substances such as asbestos and tobacco, rattling investors and insurers.
The legal dimension is also spurring scientific sleuthing to work out exactly who is responsible for the chemicals, which have been found in the environment, in wildlife and in humans. “We know PFAS are everywhere,” says Patrick Byrne, a researcher in hydrology and environmental pollution at Liverpool John Moores University in England, who published research last month showing the River Mersey had one of the worst levels recorded globally for a river basin. “To do something about the problem we need to figure out how, where and when PFAS are entering the environment so we can trace them back to their source.” Rapidly evolving scientific methods, such as chemical fingerprinting, might make the difference in the widening war against these eternal pollutants.
Forever chemicals, featuring a spine of carbon atoms with fluorine atoms attached, were first developed in the 1940s for their commercially useful properties. Their molecular structure makes them resistant to water, grease and oil; they have been used in non-stick pans, waterproof clothing, firefighting foam, fast-food packaging and cosmetics. But those qualities also render them virtually indestructible.
They linger in surface water, groundwater, soil and air, finding their way into drinking water. They persist through the food chain. The chemicals can build up in human blood and organs, and could be more harmful than microplastics. Some PFAS are suspected hormone disrupters and carcinogens, with links to obesity, high blood pressure, fertility issues and cancers of the breast, thyroid and testicles.
The biggest health impacts, Byrne says, are linked to highest exposure, whether occupational or through contaminated water supplies near plants — but the long-term effects of low exposure are less well-understood. The most common substances are made by household names such as DuPont or 3M; the latter says it will drop them by 2025.
The EU has lowered permitted levels in drinking water. The bloc is weighing a total ban, though industry wants a reprieve until alternatives are found. The US Environmental Protection Agency in the US is also recommending legally enforceable drinking limits and introducing better testing in wastewater, landfill run-off and fish tissue. In the UK, the Royal Society of Chemistry is campaigning to cut the levels in drinking water, after a third of water courses in England and Wales were found to contain medium- or high-risk PFAS levels.
The US lawsuits vary between consumers demanding compensation for personal injury, US states claiming environmental clean-up bills and water companies seeking the costs of pollutant monitoring and decontamination. But forever chemicals, which are found everywhere, seem a trickier legal proposition than asbestos, an occupational hazard, and tobacco, which poses a specific risk to smokers.
Globally, there could be as many as 15,000 different substances; some are no longer made; some were never documented. Their individual chemical signatures can be hard to tell apart. Last year, a lawsuit on behalf of nearly 12mn Ohio residents failed because PFAS levels in residents could not be apportioned to individual defendants, including 3M.
Scientists are now refining chemical fingerprinting techniques to gauge which PFAS chemicals come from which source. Byrne is exploring the use of “mass balance” studies — sampling how the chemical load in a river changes as the water flows past agricultural or industrial sites, to deduce how much each is contributing.
As forever chemicals accumulate all around us, so does informed suspicion and evidence of harm. Given that knowledge, the world needs to adjust: not just companies, who should take responsibility and change course, but also us consumers, who covet miracle products without understanding their true price.