Residential proximity to industrial plants and non-Hodgkin lymphoma

Background: A U.S. analysis suggested a relation between self-reported residential proximity to industrial plants and non-Hodgkin lymphoma (NHL) risk. Methods: Using lifetime residential histories collected from a population-based sample of 1499 Canadians with newly diagnosed, histologically confirmed NHL and 5039 population controls, we evaluated the association of residential proximity to 7 types of major heavy industry with NHL risk. Results: Overall, having lived within 0.8 km or within 3.2 km of an industrial plant was not associated with increased NHL risk. For the follicular subtype of NHL, an odds ratio (OR) of 1.48 (95% confidence interval [CI] = 1.10-1.99) was observed for women who had lived within 3.2 km (83 cases/689 controls). ORs for NHL were elevated for proximity within 3.2 km of copper smelters (OR = 5.1; CI = 1.5-17.7; 7 cases, 4 controls) and within 0.8 km of sulfite pulp mills (OR = 3.7; CI = 1.5-9.4; 9 cases, 10 controls). Conclusions: We have identified possible associations between NHL and proximity to industrial plants, which could be the result of chance or other factors associated with proximity. Studies are needed to confirm these associations and to determine whether residential proximity can result in meaningful exposure.