McGill researchers testing eco-friendly plastics
A team of researchers at Montreal's McGill University istesting a safer ingredient for plastics with the hope of replacing a component that biodegrades into a toxic by-product.
Civil engineering professor Jim Nicell, chemical engineering professor David Cooperand colleagues are hoping to develop an environmentally friendly plasticizer, the ingredient that makes plastics soft and flexible, to be added to polyvinyl chloride (PVC). This compound is used in everything from construction to cars.
Researchers say a new component is necessary after scientists discovered that plasticizercompounds were biodegrading into toxic by-products.
"What we were quite surprised with even in the very, very first study, was that as the plasticizer disappeared, the toxicity ramped up," he explained to CBC's The Current. "So something was going on. Something was being created that was fairly toxic to the microorganisms we were using to test the toxicity."
The compounds are not bound to the polymer in the plastics, so they are able to leach from PVC products, for example, Nicell said,dissolving plasticizer componentscause the new car smell.
Nicell and his students found by-products, or metabolites,of the plasticizers in the St. Lawrence River as well as in snow, rain and the air.
"What we came away from, at least that first study, was quite a surprise— these metabolites were everywhere," Nicell said. "We were starting to say, through those papers we were publishing out there, we've got to start thinking about this more seriously."
Current studies suggest the plasticizer components are not harmful to humans. However, other researchers argue that some plasticizers mimic estrogen and disrupt hormones.
Daniel Cyr of Quebec's National Institute for Science Research said the degrading plastics may be contributing to disruptions in the minnow population downstream of Montreal.
"If we look at these fish, we see ovaries in the testes," he said. "And actually more than a-third of the fish have this condition."
Cyr said the feminization of male minnows could lead to disruptions in minnow reproduction, which could lead to problems further up the food chain as the minnows are consumed by larger fish and birds.
The researchers hope to find a compound that will be as flexible and cheap to produce as standard PVC additives while not breaking down into anything harmful.
The team is currently involved in testing plasticizer/resin blends. Researchers said an Ontario-based car upholstery maker has offered assistance with testing, and in a best-case scenario, the product could be on the market within five to 10 years.