For the first time, a more “toxic” type of persistent chemical linked to cancer and infertility has been detected in U.S. homes.
When regulators began cracking down on PFAS in the early 2000s, many companies switched to shorter versions of the molecule.
However, researchers fear that these are actually more toxic than their predecessors and are harder to filter out of the water due to their size.
In the new study, researchers at Emory University, Georgia, tested 300 dust, drinking water, blood and urine samples from 80 homes in Indiana.
Between 70 and 100 percent of the per- and polyfluoroalkyl substances (PFAS) detected in these samples were short or ultra-short chain versions, it said.
PFAS is a common contaminant in many household items, from cookware to hamburger packaging. It can remain in the environment and human tissues for years or even decades before being excreted
This was the first time that the shortest versions were spotted in abundance in US homes.
Shorter PFAS chemicals didn’t come into use until the 2000s, when regulatory action was taken against longer-chain versions about health concerns.
The long-chain PFAS chemicals were first used in the 1940s for their nonstick and water-resistant properties, which meant they were applied to everything from pots and pans to food packaging and water-resistant coatings.
However, amid warnings of health impacts, companies agreed to begin phasing it out.
These microscopic man-made chemicals can take thousands of years to break down in the environment or human body, hence the name “perpetual chemicals.”
But in many cases they have been replaced by shorter-chain versions, which scientists now warn could pose even greater health risks.
The researchers said: “This is the first study to report a significant prevalence of the ultrashort exposure chemical (PFAS)… indoors and in the general population in the United States.”
“In most of the samples analyzed in this study, the levels of these two ultra-short chain PFAAs were higher or comparable to the levels of the legacy PFOS and PFOA.”
They added: “The acute toxicity of (short-chain PFAS) to freshwater invertebrates has been found to be higher than that of the longer-chain PFAAs.”
“Studies have shown that exposure to short-chain PFAAs…can cause negative effects on the reproductive, developmental, (liver) and (kidney) systems.”
In the study, published in Environmental Science and Technology Scientists have reportedly tested samples for 47 different PFAS chemicals.
In total, they discovered 39 of them, including ultra-short and short-chain PFAS.
They added that homes without carpets or that were regularly vacuumed had significantly lower levels of PFAS than those without carpets.
Homes without carpets may have had fewer chemicals because the carpets are a major source of PFAS and continually release them into the environment.
Vacuuming can also reduce the amount of PFAS in the home by removing the chemicals from the indoor environment.
About 20 percent of short-chain PFAS in humans comes from dust and drinking water, they said.
This can occur when people ingest dust or drinking water laced with minor chemicals.
But the rest came from other sources, possibly including food packaging where the chemicals are used for their non-stick and water-resistant properties.
PFAS has already been linked to many health problems, including a higher risk of kidney, testicular and thyroid cancer.
The chemicals are also known to disrupt important hormones in the body, including those related to fertility and metabolism, as well as growth and development.
But in the latest publication, researchers called for more research into the health effects – particularly of the much smaller versions.
Research already suggests that PFAS chemicals contaminate nearly half of the U.S. water supply.
Indiana University and the Indiana Clinical and Translational Sciences Institute funded this research.