Some environmental pollutants begin their lives as common household items. A metal used in household wires or a compound used to treat furniture may seem innocuous, but over time these pollutants find their way into human bodies where they can extract lasting effects on health, happiness, and according to research released Wednesday in Environmental Science & Technology, how our bodies age from the inside out.
This study, led by Michelle Plusquin Ph.D., a professor at Hasselt University’s Centre for Environmental Science, shows that a handful of chemicals that humans encounter in the environment can cause well-established hallmarks of aging to appear in the body’s cells.
Plusquin found significant effects on human telomeres and mitochondrial DNA when humans had elevated levels of copper perfluorohexane sulfonic acid (PFHxS), and perfluorooctanesulfonic acid (PFOS) levels in their blood. These may sound foreign, but they’re actually more common than your might think.
“These are compounds that are present in our environment, they have been selected based on their relevance in Flanders. However also in other countries these pollutants are found in the environment,” Plusquin tells Inverse. “These compounds can mainly enter the human body via the air, food or skin contact.”
Copper, says Plusquin, is commonly used in household wires and ends up in the environment when they’re thrown out and then incinterated. The other two chemicals, PFOS and PFHxS, belong to a class called perfluorinated chemicals (PFCs), which is made up of a cast of notoriously dangerous characters: PFOS, the EPA notes, can contaminate groundwater and was once a major ingredient in Scotchguard. PFHxS, meanwhile, are usually “used for treatment of textile and furniture to obtain a higher resistance against dirt,” adds Plusquin, and have been traced to spray-based treatments for carpets.
Pluquin’s work shows that having elevated levels of these chemicals in the body — which she detected in the urine and blood samples of 175 individuals — can have a myriad of strange effects on cellular aging.
First, they found that some classes of chemicals shortened telomeres, the protective caps on the ends of chromosomes. For example, higher urinary concentrations of copper and PFOS were significantly correlated with shortened telomere length. “Negative associations are an indication of increased cellular aging,” she explains.
But, adding to the strangeness, she also found that these pollutants had differing effects on mitochondria — the energy-producing powerhouses in the cell. People who had high levels of urinary copper and PFHxS in their blood had less mitochondrial DNA (mtDNA). But strangely, those who had high levels of PFOS tended to have higher levels of mtDNA. In this case, she says, the increase in mtDNA is probably a sign of more serious cellular issues happening because of the exposure and are not necessarily a good thing.
“Mitochondrial DNA content is known to fluctuate and a higher content might mean that there is a higher need for mitochondria. As mitochondria deliver energy to the cell, they might need more energy due to these exposures,” she says.
The good news is that agencies are already aware of the risks of some of these pollutants. The EPA, for its part, is now seeking comments for draft guidance on a proposed plan to help monitor and remove traces of PFOS and similar chemicals in groundwater.
Even if cellular aging isn’t on the forefront of the EPA’s agenda, Plusquin’s study adds a growing body of previous work showing that these chemicals can have lasting effects that may seem counterintuitive and strange effects on the human body:
“Based on previous studies I indeed think that these pollutants have lasting impact,” she adds. “Our study further clarifies how these effects happen and what can be a possible mechanism behind this effect.”
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