Gasoline stations and risk of childhood cancer: a population-based cohort study in Quebec, Canada

Gasoline (petrol) stations emit benzene and other volatile organic compounds (VOCs) into ambient air, potentially increasing childhood cancer risk, though epidemiological evidence remains limited. We investigated whether residential proximity to gasoline stations at birth was associated with childhood cancer incidence. We conducted a population-based cohort study of 824,414 newborns in Quebec, Canada. We constructed three exposure metrics at the birth residence: A) number of gasoline stations within 250 m; B) distance to the nearest gasoline station; C) sum of inverse distances to all gasoline stations within 500 m categorized as quartiles. Associations with any cancer, any leukemia, and acute lymphoblastic leukemia (ALL) were estimated using Cox models adjusted for potential confounders. Higher childhood cancer risks were suggested when at least one gasoline station was within 250 m of the residence, with risk increasing as the distance to the nearest station decreased. For newborns residing within 100 m of a gasoline station, adjusted hazard ratios (HRs) were 1.14 (95 % CI: 0.80-1.63) for any cancer, 1.35 (0.74-2.47) for leukemia and 1.27 (0.63-2.59) for ALL, compared to those with no station within 500 m. When excluding Montreal where gasoline stations must control vapor emissions, HRs were 1.42 (0.93-2.18) for any cancer and 1.55 (0.72-3.30) for leukemias. For exposure metric C, the HR for the highest exposure quartile compared to those unexposed was 1.34 (1.01-1.77) for leukemia and 1.34 (0.97-1.84) for ALL. Residential proximity to gasoline stations may increase the risk of childhood cancer, particularly leukemia, supporting measures to limit VOC emissions.