INCIDENCE OF CANCER AMONG PERSONS LIVING NEAR A MUNICIPAL SOLID-WASTELANDFILL SITE IN MONTREAL, QUEBEC

The Miron Quarry municipal solid waste landfill site in Montreal, Queb ec, generates copious quantities of methane and other gases, including a rich mixture of volatile organic compounds, some of which are recog nized or suspected human carcinogens. The site is the third largest in North America and is located in the center of a densely populated are a. Using data from the Quebec Tumour Registry, we conducted Poisson re gression analyses to evaluate whether cancer incidence among persons w ho lived near the site was higher than expected. Potential exposure to ambient air pollutants from the site was defined in terms of a set of geographic exposure zones proximal to the site. A set of reference ar eas distal from the site was selected to be similar to these exposure zones with respect to several key sociodemographic factors. Risk ratio s (RRs) were adjusted for age and calendar year. Among men living in t he exposure zone closest to the site, elevated risks were observed for cancers of the stomach (RR = 1.3, 95% confidence interval [95% CI] = 1.0-1.5); liver and intrahepatic bile ducts (RR = 1.3, 95% CI = 0.9-1. 8); and trachea, bronchus, and lung (RR = 1.1, 95% CI = 1.0-1.2). Amon g women, rates of stomach cancer (RR = 1.2; 95% CI = 0.9-1.5) and cerv ix uteri cancer were elevated (RR = 1.2, 95% CI = 1.0-1.5), but breast cancer incidence was less than expected (RR = 0.9, 95% CI = 0.9-1.0). Prostate cancer was also elevated in one of the proximal exposure sub zones (RR = 1.2, 95% CI = 1.0-1.4). Further studies at this and at oth er landfill sites are needed to confirm or refute these observations.