US EPA warns dust is an exposure pathway for the toxic PFAS chemicals at Williamtown.

THE US EPA has confirmed it views dust as an exposure pathway for the toxic chemicals that have polluted land around the Williamtown RAAF base, despite authorities in Australia downplaying the risk. 

“As with all contaminants that may be in dust or soil from an indoor or outdoor source, the EPA is concerned with this exposure pathway for PFAS,” a spokesperson said. “EPA recommends adults and children thoroughly wash their hands before eating and do normal housecleaning practices.” 

Professor of Environmental Health at Boston University, Dr Tom Webster, said there was “clearly” PFOS and PFOA in indoor dust and in the air. 

“Consequently, people are exposed to it,” he said. 

Mr Webster said that indoor pathways, water and diet could all be important routes of exposure, depending on the population. 

“If there is very high levels of PFOA or PFOS in dust in a community, then dust ingestion may turn out to be important there,” he said. 

“The indoor pathways include both dust ingestion through hand-to-mouth contact and inhalation … dermal absorption is less clear.” 

According to US EPA scientist Matthew Lorber, food is typically the main exposure pathway in the general population. However dust ingestion could be as important in children. 

“At high dust ingestion rates combined with high concentrations … the dust ingestion pathway can also equal that of food ingestion for adults as well,” he said.