Case
Abstract
The purpose of this project was to explore the risk Canadians face from ingesting carcinogens present in food and beverages. This case study illustrates how we addressed the following questions: How much of certain carcinogens are ingested by Canadians? What is the lifetime excess cancer risk (LECR) associated with these intakes? Are there differences provincially by gender, nationally by income, and nationally in urban versus rural areas? Conducting individual-level data collection was not possible due to the scope of our study, so we made use of an existing survey on individual dietary patterns in combination with government testing data on levels of carcinogenic contaminants in foods and beverages. Using Monte Carlo simulation, we were able to estimate the range and frequency of the most likely daily contaminant intakes for Canadians and associate these intake levels with LECR. For example, we found no excess risk indicated for two (lead and tetrachloroethylene [PERC]) substances, whereas the remaining three (arsenic, benzene, and polychlorinated biphenyls [PCBs]) showed that at least 50% of the population were above 10 per million excess cancers, a guideline threshold for attributing potential health-related risk. Arsenic residues, ingested via rice and rice cereal, registered the greatest disparity with LECR per million levels well above 1,000 per million at the upper bound. A majority of PCBs ingestion comes from meat where LECR per million estimates were between 50 and 400 in some groups. The primary contributor of benzene intake was from drinking water with LECR per million estimates of 35 extra cancers in the top 1% of sampled population.