Professor explores the echoes of nanos

Western Engineering professor Denis O’Carroll is assisting Environment Canada’s policy decisions around the pros and cons on certain engineering nanoparticles.

Paul Mayne // Western NewsWestern Engineering professor Denis O’Carroll is assisting Environment Canada’s policy decisions around the pros and cons on certain engineering nanoparticles.

Could that new television, tennis racket, bicycle or pair of socks you bought last week eventually be hazardous to the soil and, in turn, your local drinking water? You wouldn’t think so.

But with the engineered nanoparticles used to make such products, it’s a possibility.

Western Engineering professor Denis O’Carroll sees the tremendous technological opportunities offered by the unique properties of nanoparticles. But he also understands the concern that nanoparticles will have adverse effects on human and ecological health when released into the environment.

For his work attempting to answer these unknowns, O’Carroll was recently recognized with a Natural Sciences and Engineering Research Council of Canada Strategic Project Grants ($510,185/three years) to find answers urgently needed by policy-makers.

“If you put them (nanoparticles) in a landfill, the question would be, in 10 years, are they still there? What happens to them?” O’Carroll said. “There are some, we suspect, that will be toxic and some that won’t be. We’re looking at a selection of products, the ones mass produced, the ones that will end up in the environment and the landfills.”

Nanoparticles have been receiving extensive interest in a variety of fields due to their unique and beneficial chemical, physical and mechanical properties. With applications in biomedical, optical and electronic fields, nanoparticles – the size of an 8,000th of a human hair – can occur naturally. But they are more commonly manufactured.

Nanoparticles are intriguing to scientists because the properties of a chemical, such as silver or zinc oxide, in nano form can differ substantially from a larger particle of the same chemical. That opens up a range of new uses.

O’Carroll said nanoparticles such as quantum dots, silver nanoparticles, nanocrystalline and carbon nanotubes can be found in anything from electronics, lipstick and even sunscreen. While he expects some to be safe, others remain unknown as to their potential hazards.

“Then we’re looking at the transport of the eco-toxicity,” O’Carroll said. “You dispose of them in a landfill and they ‘get out.’

“If they get out, will they be mobile? Will they move 50 metres out, or 500 metres to a drinking water well? If it spreads to a wetland, is it going to kill it or not? Will the microorganisms (bugs) in the ground eat them and take care of it? What if it negatively impacts soil microorganisms, which provide a vital function in the soil for plant life, and it kills these bugs? That’s going to have an impact right up the food chain.”

While landfills are built with the transport of the ecotoxicity in mind, they aren’t the only disposal site. Even in something as seemingly simple as sunscreen, which uses titanium dioxide, there are concerns.

“You put sunscreen on at the beach; it will then be in the water,” he said. “It then moves from there.”

Environment Canada is a supporter of O’Carroll’s research. He expects his findings to affect their policy decisions. And just in time, too.

“There are new engineered nanoparticles coming out all the time,” O’Carroll said.