A Pesticide’s Journey Around the World
It took 20 years for the pesticide alpha-Hexachlorocyclohexane (alpha-HCH) to migrate from Asia to Newfoundland. It stayed there because of the weather.
Alpha-HCH was used in Asia 20 years ago, but Dr. Frank Wania found the highest contamination levels furthest from where it was used – in Atlantic Canada. “This really surprised us”, says the University of Toronto environmental chemist.
 The earth started cleansing itself of alpha-HCH by degrading or evaporating the chemical. But when it reached the Canadian Arctic, the cold weather and cover of ice prevented the chemical from evaporating. In fact, the Arctic can only get rid of chemicals with the help of water flows, mainly by the Labrador Current which flows south along Atlantic Canada. As alpha-HCH travels south and the temperature heats up, it evaporates. Researchers believe that the amounts of alpha-HCH found in the Arctic currently do not impact the environment.
Dr. Wania’s set up the largest network of air sampling stations to monitor alpha-HCH and other chemicals. His stations were set up in an east to west corridor from Vancouver Island to Newfoundland, and north to south from Ellesmere Island in the Canadian Arctic to Central America. Traditional air sampling techniques are very costly which limits the size of the network. Dr. Wania came up with a simple and cost-effective technique. He used an outdoor air sampler canister that contained a polymer resin to soak up chemicals like a sponge.
The contaminants were collected over a one-year period. Canadian weather stations, the Inuit, friends and colleagues helped the research team by setting up the canisters.
Contact:
Frank Wania
Tel.: (416) 287-7225 or (416) 516-6542
E-mail: frank.wania@utoronto.ca
Web site: http://www.utsc.utoronto.ca/~wania
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