At least 45 per cent of the United States tap water is contaminated with toxic "forever" chemicals, according to a study by a government agency.
Found in everyday products such as non-stick frying pans, poly-fluoroalkyl substances (PFAS) can linger in the environment for a long time and have been linked to serious health conditions including cancer and birth defects.
The chemicals can reach water supplies through industrial discharges and leaching from landfill sites.
"This USGS study was the first to compare PFAS in tap water from both private and public supplies on a broad scale throughout the country," Kelly Smalling, a USGS scientist and the study's lead author, told AFP on Friday.
The paper was published this week in the journal Environment International and found exposure to PFAS was similar in samples collected from unregulated private wells and regulated public supply. Overall, the study estimated the probability of PFAS being observed in the water at 75 per cent in cities and 25 per cent in rural areas.
Filters recommended, not bottled water
There are more than 12,000 types of PFAS, not all of which are detectable by current testing. For the purposes of the current research, USGS tested for only 32 types.
The team collected samples from 716 nationally representative locations. Most exposures occurred in urban areas or places with known high concentrations of PFAS, such as industrial and waste sites.
These included the Great Plains, which runs down the middle of the country, the Great Lakes in the mid-east, as well as cities along the East and West Coasts.
Concerned residents can look up PFAS levels in the zip code via a website maintained by the nonprofit Environmental Working Group (www.ewg.org).
The Environmental Protection Agency (EPA) offers advice for in-home treatment options. Filters, including those that reverse osmosis technology, activated carbon, and ion exchange have been shown to be highly effective at removing them.
Bottled water may not be a good alternative. A 2022 study by USGS found bottled water was frequently contaminated with inorganic and organic compounds, with arsenic, lead, and uranium among the most common.
Last month, US industrial conglomerate 3M announced it would pay as much as $12.5 billion to settle numerous claims from US public water systems that accused the company of tainting their supplies.
The company has also agreed to large settlements in the Netherlands and Belgium, and announced in December it would stop manufacturing PFAS substances by the end of 2025.