HQ Team
July 7, 2023: About 45% of the US tap water contains one or more types of “forever chemicals,” found in the linings of fast-food boxes and non-stick cookware to fire-fighting foams, raising health concerns, according to a US Geological Survey study.
High concentrations of one or more types of chemicals called per and polyfluorinated alkyl substances, or PFAS, may lead to adverse health risks in people, according to the U.S. Environmental Protection Agency.
As these chemicals break down very slowly, PFAS are commonly called “forever chemicals.” Their persistence in the environment and prevalence across the country makes them a unique water-quality concern.
Research is still ongoing to better understand the potential health effects of PFAS exposure over long periods of time. There are more than 12,000 types of PFAS, not all of which can be detected with current tests. The USGS study tested for the presence of 32 types.
700 samples
The government agency tested tap water samples from more than 700 residences, businesses, and drinking-water treatment plants across the country for the presence of PFAS.
The USGS research marks the first time anyone has been tested for and compared PFAS in tap water from both private and government-regulated public water supplies on a broad scale throughout the country.
The data were used to model and estimate PFAS contamination nationwide.
“USGS scientists tested water collected directly from people’s kitchen sinks across the nation, providing the most comprehensive study to date on PFAS in tap water from both private wells and public supplies,” said Kelly Smalling, the study’s lead author.
“The study estimates that at least one type of PFAS – of those that were monitored – could be present in nearly half of the tap water in the U.S. Furthermore, PFAS concentrations were similar between public supplies and private wells,” the USGS research hydrologist said.
32 individual PFAS compounds
The study tested 32 individual PFAS compounds using a method developed by the USGS National Water Quality Laboratory.
The most frequently detected compounds in this study have been PFBS, PFHxS, and PFOA. The interim health advisories released by the Environment Protection Agency in 2022 for PFOS and PFOA were exceeded in every sample in which they were detected in this study.
In the US, the EPA regulates public water supplies, and homeowners are responsible for the maintenance, testing, and treatment of private water supplies.
Scientists collected tap water samples from 716 locations representing a range of low, medium, and high human-impacted areas.
The low category includes protected lands — the medium includes residential and rural areas with no known PFAS sources, and the high includes urban areas and locations with reported PFAS sources such as industry or waste sites.
“Most of the exposure was observed near urban areas and potential PFAS sources. This included the Great Plains, Great Lakes, Eastern Seaboard, and Central/Southern California regions,” according to the study.
Fluoropolymers
The per-and polyfluoroalkyl substances (PFAS) are a group of chemicals used to make fluoropolymer coatings and products that resist heat, oil, stains, grease, and water. Fluoropolymer coatings can be in a variety of products. These include clothing, furniture, adhesives, food packaging, heat-resistant, non-stick cooking surfaces, and the insulation of electrical wire.
Many PFAS, including perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), are a concern because they do not break down in the environment, can move through soils and contaminate drinking water sources, and build up (bioaccumulate) in fish and wildlife.
PFAS are found in rivers and lakes and in many types of animals on land and in the water. PFAS persist in the environment and exposure in people can occur by consuming PFAS-contaminated water or food. Exposure may happen by using products that contain PFAS.
Human health effects from exposure to low environmental levels of PFAS are uncertain, according to the Centers for Disease Control and Prevention.
Studies of laboratory animals given large amounts of PFAS indicate that some PFAS may affect growth and development.
These animal studies indicate PFAS may affect reproduction, thyroid function, and the immune system, and injure the liver.
1 Comment