Association between residential proximity to environmental pollution sources and childhood renal tumors.

BACKGROUND: Few risk factors for childhood renal tumors are well established. While a small fraction of cases might be attributable to susceptibility genes and congenital anomalies, the role of environmental factors needs to be assessed. OBJECTIVES: To explore the possible association between residential proximity to environmental pollution sources (industrial and urban areas, and agricultural crops) and childhood renal cancer, taking into account industrial groups and toxic substances released. METHODS: We conducted a population-based case-control study of childhood renal cancer in Spain, including 213 incident cases gathered from the Spanish Registry of Childhood Tumors (period 1996-2011), and 1278 controls individually matched by year of birth, sex, and region of residence. Distances were computed from the respective subject's residences to the 1271 industries, the 30 urban areas with ≥75,000 inhabitants, and the agricultural crops located in the study area. Using logistic regression, odds ratios (ORs) and 95% confidence intervals (95%CIs) for categories of distance to pollution sources were calculated, with adjustment for matching variables and socioeconomic confounders. RESULTS: Excess risk (OR; 95%CI) of childhood renal tumors was observed for children living near (≤2.5km) industrial installations as a whole (1.97; 1.13-3.42) - particularly glass and mineral fibers (2.69; 1.19-6.08), galvanization (2.66; 1.14-6.22), hazardous waste (2.59; 1.25-5.37), ceramic (2.35; 1.06-5.21), surface treatment of metals (2.25; 1.24-4.08), organic chemical industry (2.22; 1.15-4.26), food and beverage sector (2.19; 1.18-4.07), urban and waste-water treatment plants (2.14; 1.07-4.30), and production and processing of metals (1.98; 1.03-3.82) -, and in the proximity of agricultural crops (3.16; 1.54-8.89 for children with percentage of crop surface ≥24.35% in a 1-km buffer around their residences). CONCLUSIONS: Our study provides some epidemiological evidence that living near certain industrial areas and agricultural crops may be a risk factor for childhood renal cancer.