Dolphins poisoned by industrial chemical used in nonstick pans, study finds

A new study on chemical persistence in the environment reveals that a human-made industrial chemical used in nonstick cooking pans, pesticides and carpet-cleaners have been found in a variety of aquatic wildlife species in North America including fish, birds and dolphins.

Led by Dr. Amila De Silva from the Canada Centre for Inland Waters, a division of the federal government’s department of Environment and Climate Change, the research focused on a little-studied group of chemicals called perfluoroalkylphosphinic acids or PFPIAs, once incorporatedinto pesticides and more recently found in stain-resistant carpet sprays and nonstick cooking surfaces.

A first of its kind, the study sampled blood plasma from three animal species -double-breasted cormorants, Northern pike and bottlenose dolphin – to see how pervasive PFPIAs are in the environment. Surprisingly, they found PFPIAs in every animal tested.

“The 100 per cent detection frequency suggests a ubiquitous presence of PFPIAs in North American aquatic environments,” say the study’s authors, “with anthropogenic impacts such as wastewater, agriculture, and, possibly, particle-bound and water-borne transport from source regions.”

According to a CNN report, the US Environmental Protection Agency put a restriction on the use of PFPIAs for use in pesticides beginning in the year 2006, stating they had “identified human health environmental risks of concern.”Known for their surfactant properties, PFPIAs accumulate in the body’s protein-rich tissues and can be found in blood plasma and the liver. And because they are not broken down by normal environmental processes (using sunlight, water and microbes, for example), their environmental persistence makes them an obvious concern, says De Silva.

“Previous work by other scientists in three separate publications have shown PFPIAs are found in human blood samples from North America and Germany,” says De Silva, who notes that although the compounds are restricted in the US, Canada has yet to take similar steps to curb their use, making them a potential threat to waterways and ecological systems.

“That has implications when we look at the Great Lakes, which are binational,” says De Silva.

Researchers purposefully sampled animals from a variety of regions in order to get a widespread look at the environmental accumulation of PFPIAs, testing cormorants from five different breeding colonies in the Great Lakes basin, Northern pike caught at two locations along the St. Lawrence River and bottlenose dolphins that were sampled as part of a capture-release health assessment program from Sarasota Bay, Florida, in the Gulf of Mexico.

The team found that animals from the more rural and remote areas had the lowest concentrations of PFPIAs in comparison to areas with more industrial and wastewater inputs. The authors note that tested dolphins had the highest concentration of contaminants, likely due to their higher status along the food chain which would allow for chemical build-up by the process known as biomagnification.

The researchers conclude that more research is needed on the ecological impact of PFPIAs and their potential risk for human health.

The new study was published in the journal Environmental Science & Technology.

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