September 29, 2016 - 6:00 AM
Government research has found the presence of a chemical used in pesticides in fish, birds and a mammal from the St. Lawrence River to the south Florida coast.
"We found 100 per cent detection frequency of these compounds in the blood of those organisms," said Amila De Silva, an environmental chemist with Environment Canada.
De Silva said levels remain low, but the little-studied family of chemicals known as PFPIAs in northern pike, cormorants and dolphins suggests related substances may also be in the environment.
"There are lots of other kindred chemicals that just haven't been reported," De Silva said.
"The methods haven't been developed for looking at them."
De Silva decided to look into PFPIAs because little is known about them, even though they are widely used in pesticides. Scientists already know similar chemicals persist in the environment for a long time and concentrate in animals higher up the food chain.
"That piqued our interest and that's why we thought to look at them."
She and her team examined northern pike collected in 2011 from two locations near Montreal Island in the St. Lawrence River, cormorants from bird colonies in the Great Lakes from 2010 to 2012 and bottlenose dolphin samples between 2004 to 2009 from Sarasota Bay in Florida and Charleston Harbor, S.C.
"We found (PFPIAs) in every sample that we looked at."
The levels were low and measured in billionths of a gram per gram of body weight.
Effects? Nobody knows.
"That is a complete grey area," De Silva said. "There are very few reported studies on PFPIA in general and in terms of toxicity studies, there are none."
The study points to the need for more research into the effects of compounds such as PFPIAs, which have also been found in human blood, De Silva said.
"We can report that a cormorant from the Great Lakes had five nanograms per (millilitre) of PFPIA in its blood. But how does that translate into risk if we don't have the research to answer those questions?
"In terms of the impact on the organism, we don't have that information."
Some toxicity studies are being done on PFPIAs in both the United States and Canada.
— Follow Bob Weber on Twitter at @row1960
News from © The Canadian Press, 2016