Recent studies estimate greater than 47,000 tons of poly- and perfluoroalkyl substances (PFASs) have been released from consumer products into the environment over the past six decades. A large fraction of these releases remain concentrated at or around contaminated sites.
Some PFASs with long carbon chain lengths bioaccumulate in food webs, providing another important vector for human exposure. Recently, some shorter chain alternatives have also been detected. Long-chain PFASs are defined as those containing more than six fluorinated alkyl groups, such as PFOS and PFOA.
Overall risks to human health associated with PFAS exposures near contaminated sites depend on their propensity for transport away from contaminated sites, lifetime in the environment, and the background levels of exposure from other sources such as consumer packaging and clothing. Diverse human exposure pathways can make exposure source identification difficult; this will be directly addressed by STEEP’s research through the fingerprinting of PFAS signatures in drinking water and fish.
What are PFASs?
PFASs are among the most immunotoxic environmental chemical contaminants known. They are extremely resistant to environmental degradation and they are ubiquitous in humans and the environment and will remain so for the foreseeable future. PFASs have been produced for over 60 years, but it is only in the last 20 years or so that their risk to human health has been recognized. High exposure can lead to various adverse human health effects including altered metabolic functions, liver toxicity, and obesity.
People are exposed to PFASs in one of two ways. PFASs either enter the environment at manufacturing or industrial sites and find their way to human consumption through drinking water or the food web. Also, people can be exposed through direct use of consumer products that have been treated with PFAS chemicals, such as water resistant clothing or takeout food containers.