Aug. 31 (UPI) -- Harmful forever chemicals called PFAS can become airborne and circulate indoors, according to a new study.
Using a new measurement technique, researchers detected surprisingly high concentrations of PFAS in air sampled from kindergarten classrooms, university offices and laboratories.
In some indoor settings, scientists detected toxin levels as high as those measured at outdoor clothing and carpet stores, where PFAS-treated products are bought and sold.
Researchers shared the results of their survey in a new paper, published Tuesday in the journal Environmental Science & Technology Letters.
"Food and water are known to be major sources of PFAS exposure. Our study shows that indoor air, including dust, is another source of exposure to potentially harmful forever chemicals," senior study author Rainer Lohmann said in a press release.
"In fact, for children in homes or schools with old PFAS-treated carpets, inhalation may be even more important than dust as an exposure pathway to volatile PFAS that eventually could biotransform to more persistent and harmful PFAS," said Lohmann, a professor at the University of Rhode Island whose research focus is marine and atmospheric chemistry.
Per- and polyfluoroalkyl substances, or PFAS, are a class of synthetic compounds used in a variety of industrial processes and found in dozens of household items.
They have been linked to a variety of health problems, including cancer and high cholesterol, and a report published earlier this year found the toxins are accumulating in municipal drinking water all over the United States.
The health threats posed by PFAS have inspired U.S. lawmakers to take action as the chemicals have been found in drinking and ground water across the country, including after years of use at military bases.
In April, Reps. Debbie Dingell, D-Mich., and Fred Upton, R-Mich., introduced bipartisan legislation on Tuesday to designate PFAS as hazardous substances and set a national drinking standard for the "forever chemicals.
A separate analysis published Tuesday by the Environmental Working Group spotlighted six U.S. military sites with ground water PFAS levels thousands of times higher than the U.S. Environmental Protection Agency and most states permit.
But as the latest findings show, PFAS contamination isn't limited to water.
To measure the concentrations of airborne PFAS in various indoor settings, scientists affixed polyethylene sheets to the ceilings of several kindergarten classrooms, offices and laboratories.
Researchers also placed a sheet in one single family home, an elevator, two Rhode Island carpet stores and the storage room of an outdoor clothing store in California.
Several classrooms and labs at the University of Rhode Island had higher PFAS concentrations than those measured in the storage room in California. The highest PFAS concentrations were measured in the two Rhode Island carpet stores.
"PFAS were formerly used as stain and water repellents in most carpets," said lead author Maya Morales-McDevitt. "Fortunately, major retailers including The Home Depot and Lowe's now only sell PFAS-free carpets. We believe that slowly smaller retailers will do so as well."
Families can reduce PFAS exposure by replacing carpets, but a variety of other products can emit forever chemicals, including clothing, shoes, building products and furniture.
"As long as they continue to be used in products, we'll all be eating, drinking, and breathing PFAS," said co-author Tom Bruton, senior scientist at the Green Science Policy Institute. "We need to turn off the tap and stop all unnecessary uses of PFAS as soon as possible."