Toxic PFAS detected in household dust samples in New Castle, Del.

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Toxic PFAS chemicals have been detected in household dust sampled inside residents’ homes in New Castle, Del., according to a new investigation by the Centers for Disease Control and Prevention.

The city has a history of PFAS contamination associated with the National Guard’s use of firefighting foam at a base at the Wilmington Airport in New Castle.

The so-called “forever chemicals” have since been removed from public drinking water in the city.

However, residents continue to have exceedingly high levels of PFAS in their blood — likely from drinking contaminated water for many years — according to a CDC study published in 2022.

But as the most recent CDC study shows, drinking contaminated water is not the only pathway to exposure, researchers say.

New Castle residents are also exposed to PFAS particles throughout their homes. In some cases, PFAS detected in household dust samples directly correlates with chemical levels in their blood, according to the study from the CDC’s Agency for Toxic Substances and Disease Registry published this week.

“PFAS contamination is vast and complex and this latest report underscores that exposure likely goes well beyond drinking water,” said Delaware Department of Natural Resources and Environmental Control Secretary Shawn Garvin in a statement. “Unfortunately, PFAS is not a problem with a quick and easy solution. This issue did not occur overnight and finding solutions will take time. But we are making progress.”

PFAS chemicals have tainted the water, air and soil across the country for decades. The chemicals have been widely used in consumer products such as nonstick cookware, waterproof clothing and some food packaging, as well as in firefighting foam.

Water supplies located near military bases and airports —  from Bucks and Montgomery counties in Pennsylvania to the cities of New Castle and Dover in Delaware — have been particularly impacted by the historical use of firefighting foam.

Almost half of drinking water in the U.S. contains PFAS, according to the U.S. Geological Survey.

The consequences of exposure to PFAS are long-lasting — the compounds can stay in the environment and the human bloodstream for years. The chemicals have been linked to some cancers, thyroid disease, ulcerative colitis, developmental delays in children and other health conditions.

There have been numerous lawsuits against companies that manufacture and use the chemicals, such as DuPont and its successor companies and 3M, alleging they knew about the dangers as early as the 1960s.

The CDC began evaluating PFAS levels in people’s blood in 2018, focusing on locations with known contamination. Following the research, the agency agreed to conduct additional testing in New Castle and Westfield, Mass., to determine other pathways of PFAS exposure.

Researchers at the CDC’s Agency for Toxic Substances and Disease Registry detected several types of PFAS in outdoor and indoor air in both cities, as well as in household dust found on surfaces and in vacuum cleaners.

“It doesn’t mean [PFAS in their blood is] coming from the dust,” said Arthur Frank, a public health professor at Drexel University who was not involved in the study. “It just means that wherever the household is being contaminated from is getting both into the dust and into the people.”

However, people may ingest or inhale PFAS-contaminated dust, according to the CDC.

Researchers hope the findings will help public health officials better understand PFAS exposure and its effects on human health, and help educate consumers about PFAS.

Scientists say as much as 80% of PFAS exposure may stem from everyday products. Health officials recommend people dust with wet cloths, vacuum with HEPA filters and buy items that are certified PFAS-free.

Frank of Drexel also recommends people avoid heating food in plastic containers in the microwave, which can cause PFAS to leach.

“You should stop using plastic materials, probably for food storage and for certainly heating things in your microwave,” he said. “It’d be far better to use ceramic or glass materials in the microwave to heat food.”

Environmental and public health officials in Delaware plan to further study local PFAS sources and potential exposures.

“Delaware agencies are fully committed to collaborating with state, federal and community partners to protect the health of every Delawarean,” said Josette Manning, Secretary of the Delaware Department of Health and Social Services, in a statement. “We’re well familiar with the need to monitor PFAS in drinking water. This latest study underscores our shared responsibility to study, recognize, and address the potential impacts of PFAS exposure from a wide range of other sources as well.”