SAN FRANCISCO, Aug. 9 (Xinhua) -- A group of researchers has traced highly fluorinated chemicals in drinking water supply around many of the military bases, airports and industrial sites in the United States to fire-fighting foam.
The researchers, with University of California, Berkeley, and Harvard University, estimate that at least 6 million people may be drinking water contaminated with the highly fluorinated chemicals, which have been linked to kidney and testicular cancer, high cholesterol, obesity and endocrine disruption in humans.
The chemicals, poly- and perfluoroalkyl substances (PFAS), are used widely to extinguish liquid fuel fires. During training exercises, they are referred to as aqueous film-forming foams (AFFFs) as they contain a fluorocarbon surfactant, such as perfluorooctane sulfonate that reduces surface tension and increases spreading over the liquid.
In a paper published Tuesday in the journal Environmental Science & Technology Letters, the researchers identified where water supply exceeds the recent U.S. Environmental Protection Agency health advisory levels for perfluorooctanoic acid and perfluorooctane sulfonic acid.
They then used sophisticated mapping technology to trace possible sources of contamination to fire-fighting foam at military sites and airports, industrial sites and wastewater treatment plants.
"During fire-fighting practice drills, large volumes of these toxic chemicals wash into surface and ground waters and can end up in our drinking water," said Arlene Blum, a co-author of the study and visiting scholar in the Department of Chemistry at UC Berkeley. "Such persistent chemicals should only be used when essential, and never for training."
Blum believes that the problem of fluorinated chemicals in drinking water is enormous, according to a news release from UC Berkeley, and that the available data only reveals the tip of an iceberg of contaminated drinking water.