Residential proximity to environmental pollution sources and risk of rare tumors in children

Abstract

BackgroundFew epidemiologic studies have explored risk factors for rare tumors in children, and the role of environmental factors needs to be assessed. ObjectivesTo ascertain the effect of residential proximity to both industrial and urban areas on childhood cancer risk, taking industrial groups into account. MethodsWe conducted a population-based case-control study of five childhood cancers in Spain (retinoblastoma, hepatic tumors, soft tissue sarcomas, germ cell tumors, and other epithelial neoplasms/melanomas), including 557 incident cases from the Spanish Registry of Childhood Tumors (period 1996–2011), and 3342 controls individually matched by year of birth, sex, and region of residence. Distances were computed from the residences to the 1271 industries and the 30 urban areas with ≥75,000 inhabitants located in the study area. Using logistic regression, odds ratios (ORs) and 95% confidence intervals (95%CIs) for categories of distance to industrial and urban pollution sources were calculated, with adjustment for matching variables and socioeconomic confounders. ResultsChildren living near industrial and urban areas as a whole showed no excess risk for any of the tumors analyzed. However, isolated statistical associations (OR; 95%CI) were found between retinoblastoma and proximity to industries involved in glass and mineral fibers (2.49; 1.01–6.12 at 3km) and organic chemical industries (2.54; 1.10–5.90 at 2km). Moreover, soft tissue sarcomas registered the lower risks in the environs of industries as a whole (0.59; 0.38–0.93 at 4km). ConclusionsWe have found isolated statistical associations between retinoblastoma and proximity to industries involved in glass and mineral fibers and organic chemical industries.