Instead, say the researchers, water contamination resulted from many failures in a complex system involving workers, local governments, regulatory bodies and provincial governments. "There are interactions and relationships across all these levels, and everybody has a role to play," says Kim Vicente, a professor in the Department of Mechanical and Industrial Engineering and co-author of the study. "When you get cracks across those relationships, you get these kinds of systems accidents."

In May 2000, seven residents of Walkerton died after drinking water contaminated with E.coli, and in April 2001, nearly 6,000 people in North Battleford became ill after drinking water contaminated with the Cryptosporidium parvum protozoan.

Vicente is an expert on human factors engineering, which examines technology that can accommodate human capabilities and limitations. He currently holds the Jerome Clarke Hunsaker Distinguished Visiting Professorship at the Massachusetts Institute of Technology in Cambridge, Mass. Along with co-author Dennis Woo, his research assistant, he examined common factors between Walkerton and North Battleford.

The study, which will be published in the June 2003 issue of the journal Reliability Engineering & System Safety, examines the two outbreaks using an analytic system known as the Rasmussen framework. This framework looks at risk management in critical systems such as aviation, health care and drinking water management.

While details of each outbreak differ slightly, Vicente found that they share common factors such as budget reductions at the governmental level and lack of regulatory oversight. "The weaknesses at these government and organizational levels tended to appear in both accidents," he says. "We need to do a
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Contact: Nicolle Wahl
nicolle.wahl@utoronto.ca
416-978-6974
University of Toronto
29-Apr-2003