If asked what humans have in common with polar bears, it may surprise many to learn that we share the title for world’s most contaminated organisms when it comes to a group of pollutants called perfluorinated acids.
Scott Mabury, professor of chemistry at the University of Toronto, was the first to trace these pollutants back to their source, enabling policy changes on products that put their precursors into the air.
Mabury is an environmental chemist: he studies the chemistry of the environment and how chemical compounds move and change, and how they may cause harm to ecosystems and the organisms that inhabit them.
Chemical pollutants act as chemical probes for what can happen in different environments, from soil to water to air. Mabury uses them to tease apart the mechanisms for how change happens.
In the story of perfluorinated acid contamination, no one knew that the source chemicals were pollutants. It was only through metabolic transformations after their release in the environment that the final pollutants were created.
“These things can be inhaled and we will metabolically convert them from the precursor alcohols into the perfluorinated acids, the final compounds that no longer degrade,” says Mabury. “And they stick around in our bodies for three, four, five years. So they tend to reach relatively high concentrations.”
The precursor alcohols can easily become airborne. They were globally used in treatments for carpets and papers, and in the manufacture of products like paints, adhesives, polishes, and electronics.
“They were waste products that (neither) industry nor government knew were there, so they didn’t know to regulate them,” explains Mabury. “We discovered them in the atmosphere, worked them back to where they came from.”
This work led to Environment Canada and the United States Environmental Protection Agency enacting new regulations. In turn, industry stepped up and produced cleaner alternatives.
“We’re endeavouring now at designing much greener alternatives: chemicals that will impart the surface properties that fluorinated chemicals do,” adds Mabury, “but also when they get released in the environment that Mother Nature will just chew them up, back to their original constituents. That would be a beautiful thing.”