persistent organic pollutants

October 8, 2024

PFAS levels increasing in Arctic animals, study finds

By Douglas Main

Concentrations of toxic pollutants known as per- and polyfluoroalkyl substances (PFAS) are continuing to increase in Arctic animals such as polar bears despite efforts to rein in their use, according to a new study.

One type of PFAS known to be of particular harm, PFOS, was largely phased out starting 20 years ago. But average levels in several populations of polar bears and seals have continued to go up in recent years, according to the paper, published this month in the journal Science of the Total Environment.

Exposure to some PFAS, also called “forever chemicals,” increases the risk of a wide range of health harms to humans and animals, scientists have found.

“There’s nothing in the Arctic that isn’t contaminated by PFAS,” says study co-author Rainer Lohmann, who studies persistent organic pollutants as an environmental chemist at the University of Rhode Island. “It’s just very sad.”

Of the animals looked at in the study, polar bears had the highest concentrations of various types of PFAS, approximately 10 times what has been found in people in the region.

Troubling findings were also seen for a type of PFAS called PFNA. Average concentrations of PFNA have steadily risen over the last couple decades in all populations of polar bears and seals studied, and appear to still be on the rise, according to the paper.

The latest published work adds to more than 200 studies that have turned up PFAS in well over 600 animal species, including those that are threatened or endangered.

August 15, 2024

Early exposure to toxic TCDF messes with gut bacteria later in life, finds study in mice

By Shannon Kelleher

Early-in-life exposure to a common toxic chemical found in some foods and in breastmilk may disrupt healthy bacteria in the gut and increase a person’s risk for developing various diseases later in life, according to a new animal study.

The findings, published Aug. 14 in the journal Environmental Health Perspectives, may shed light on the link between childhood exposure to persistent organic pollutants (POPs) and widespread obesity and diabetes in adults, according to the authors.

More than 460 million people worldwide have diabetes, while global obesity levels have tripled since 1975. One in three US adults and one in six children are considered obese, according to a 2023 report.

“This study emphasizes the importance of the microbiome as a key target of early life environmental pollutant exposure,” the paper states. Exposure to the children can occur before birth when pregnant women are exposed to the chemicals as well as after birth through breastfeeding.

Although previous research has identified correlations between exposure to POPs and obesity and type 2 diabetes, the microbiome’s role has not been clear, according to the study.

The researchers fed infant mice pills containing the chemical 2,3,7,8-tetrachlorodibenzofuran (TCDF) for five days, collecting data on their gut microbiomes right after the mice were fed the last dose and again three months later, when they had reached young adulthood. Compared to a control group that was not fed TCDF, the mice had higher body weight and glucose intolerance – a hallmark of diabetes – long after they ingested the chemical.

The researchers also measured lower levels of two bacteria species important for gut health in the mice fed TCDF when they were four months old, as well as markers of immune problems and inflammation in the intestines.

April 11, 2023

Banned carcinogen found in 88% of household objects, says new study

By Grace van Deelen

A banned chemical that potentially causes cancer in humans has been discovered in a wide array of household products, according to a study out today.

Short-chain chlorinated paraffins (SCCPs) are a group of chemicals that are used in metalworking and the production of PVC, plastics, rubbers, and other materials. They are persistent chemicals, meaning they don’t degrade in the environment and accumulate in animals. Chlorinated paraffins have been detected in various wildlife and in human milk and blood. The 2017 Stockholm Convention listed SCCPs under their Annex A, which urges the elimination of the chemicals. SCCPs were largely prohibited in Canada in 2013 and in the US in 2012.

A study published today in the journal Environmental Science: Processes & Impacts, shows that SCCPs are still widely present in household goods, indicating the need for more regulatory action. Researchers found SCCPs in 84 of 96 household goods tested in Canada. All the household goods were purchased at least one year after Canada’s prohibition of the chemical went into effect, suggesting that chemical regulation against SCCPs has not been entirely effective.

“We found [SCCPs] in almost everything, which was very surprising to us,” said Steven Kutarna, a PhD candidate at the University of Toronto and the lead author of the paper.

November 4, 2022

Industrial chemicals threaten hunting and fishing traditions

By Shannon Kelleher

For more than a century, members of the indigenous Penobscot Nation, who live along the Maine river from which they take their name, have mourned the loss of the migratory fish that sustained their ancestors.

Dams built by developers in the 19th and early 20th centuries along the Penobscot River cut off access to the ocean, preventing native fish from returning each year to spawn in their historic habitats.

A years-long restoration project was completed in 2016, reopening 2,000 miles of river to Atlantic salmon and other fish considered important nutritional sources for the people of the region as well as fish-eating birds and mammals, including eagles and river otters. Eleven species of native migratory fish returned to the Penobscot River due to the restoration project.

“We were very excited,” said Daniel Kusnierz, the tribe’s water resources program manager. “These would have been the species the tribe would have relied on heavily for food.”

But the celebration was short-lived: Though the fish have returned, researchers from the Penobscot Nation and government agencies have documented an array of toxic chemicals contaminating them, including dreaded per- and polyfluoroalkyl substances linked to various cancers and other health problems.

Known as PFAS, or “forever chemicals,” the class of industrial chemicals is almost impossible to eradicate and is increasingly documented in fish and other wildlife around the world. The plight of the Penobscot Nation is yet another example of how people everywhere are finding it increasingly difficult to escape the legacy of industrial pollution that threatens human and environmental health.