Gas Station Proximity Linked to Childhood Leukemia Risk

Volatile organic compounds (VOCs) have been linked to higher childhood cancer risk across the province of Quebec in Canada, with the highest overall risks seen for any leukemia and acute lymphoblastic leukemia (ALL), according to new research linking gas station location and childhood cancer incidence.¹ Investigators explained that the carcinogenicity of benzene, in particular, has been linked to adult-onset leukemias and hematotoxicity^2,3 but that few analyses have examined the impact of VOC exposure in early life.

“For most childhood cancers including leukemias, the etiology remains largely unknown. There is growing attention to environmental and early-life factors that may contribute to carcinogenesis during critical developmental windows, such as during pregnancy and early childhood,” the study authors wrote in Environmental Pollution.¹ “Among these factors, exposure to ambient air pollutants, including [VOCs] such as benzene, has raised concern.”

For their population-based cohort study, they included all births recorded in Quebec between January 1, 2007, and December 31, 2020, with the children followed to first cancer diagnosis, death, or age 15, whichever came first. The final follow-up date was March 31, 2023. Their 3 exposure metrics, all in relation to birth residence, were gas stations within 250 meters (metric A), distance to the nearest gas station (metric B; ≤100, 101-250, 251-500, and >500 meters), and sum of inverse distances to all gas stations within 500 meters (metric C).

From among the 824,414 births included, 0.19% (n = 1535) developed any cancer, 0.06% (n = 465) developed a leukemia, and 0.04% (n = 359) developed ALL. Among the entire cohort, male children accounted for 55% of the cancer and leukemia diagnoses, and the most common ages of diagnosis were 0 to 4 years, in 60% of the any-cancer cohort, 57% of the leukemia cohort, and 53% of the ALL cohort. Their mothers were typically aged 20 to 34 years (77% overall and 77%-79% across the 3 subgroups), had no maternal comorbidities (82% overall and across the subgroups), lived in areas of low to midlevel socioeconomic status (61% overall and leukemia cohorts; 62%, any-cancer cohort; 64%, ALL cohort), and lived in urban locations (88%-90%).

For metric A, most patients overall and from each cohort did not live within 250 meters of a gas station (86% overall; 85%, any cancer and leukemia; 84%, ALL); for metric B, 58%, 56%, 57%, and 57%, respectively, were more than 500 meters from the nearest gas station; and for metric C, among those with exposure—58%, 56%, 56%, and 57% had no exposure—high exposure (quartiles 3 and 4) was most common (quartile 3, overall: 10%; quartile 4, 13% with any cancer, 14% each with leukemia and ALL).

The highest childhood cancer risks were seen when at least 1 gas station was within 250 meters of the residence for any cancer (HR, 1.02; 95% CI, 0.87-1.18), leukemia (HR, 1.14; 95% CI, 0.87-1.50), and ALL (HR, 1.16; 95% CI, 0.85-1.58). They remained elevated for leukemia (HR, 1.06; 95% CI, 0.56-1.99) and ALL (HR, 1.12; 95% CI, 0.55-2.26) at 2 or more stations but dropped slightly overall (HR, 0.97; 95% CI, 0.69-1.38).

Considering distance to the nearest gas station, the highest increased risks were seen for 100 meters or less across all groups:

• Any cancer: HR, 1.14 (95% CI, 0.80-1.63)
• Leukemia: HR, 1.35 (95% CI, 0.74-2.47)
• ALL: HR, 1.27 (95% CI, 0.63-2.59)

For sum of inverse distance, greater risks were seen with the high exposure vs low exposure, respectively:

• Any cancer: HR, 1.18 (95% CI, 1.00-1.38) vs HR, 1.17 (95% CI, 1.00-1.38)
• Leukemia: HR, 1.34 (95% CI, 1.01-1.77) vs HR, 1.05 (95% CI, 0.77-1.43)
• ALL: HR, 1.34 (95% CI, 0.97-1.84) vs HR, 1.12 (95% CI, 0.79-1.57)

A subgroup analysis was conducted that excluded Montreal and looked at risk of any cancer and leukemia; the city has to control vapor emissions at its stations. The risk was lower for both in Montreal vs all of Quebec for individuals who lived 100 or fewer meters from a gas station for both outcomes:

• Any cancer: HR, 0.85 (95% CI, 0.45-1.60) vs HR, 1.42 (95% CI, 0.93-2.18)
• Leukemia: HR, 1.15 (95% CI, 0.42-3.18) vs HR, 1.55 (95% CI, 0.72-3.30)

In addition, children whose mothers had comorbidities and who lived 101 to 250 meters from the nearest gas station had a higher risk of leukemia (HR, 2.03; 95% CI, 1.15-3.57) compared with children whose mothers had no comorbidities (HR, 0.95; 95% CI, 0.68-1.32).

Based on these results, the authors concluded that each of the metrics they evaluated “were consistent in suggesting a trend towards elevated risks among individuals residing in very close proximity to at least 1 gas station.” The children included face a higher risk of not only cancer overall, but particularly leukemia. Although not proving causation, the findings strengthen concerns about early-life exposure to benzene and other VOCs and underscore the importance of preventive strategies, including stronger emissions regulations, to limit residential proximity to high-emission sources.

Limitations on these findings are potential exposure misclassification, because residential promixity to gas stations was used vs accounting for individual-level exposure; the authors only used postal code at birth and did not account for moves; inability to account for all potential confounders; administrative data constraints; and the study’s observational design.

References

1. Brizard F, Auger N, Smargiassi A, et al. Gasoline stations and risk of childhood cancer: a population-based cohort study in Quebec, Canada. Environ Pollut. 2026;394:127737. doi:10.1016/j.envpol.2026.127737
2. Rinsky RA, Young RJ, Smith AB. Leukemia in benzene workers. Am J Ind Med. 1981;2(3):217-245. doi:10.1002/ajim.4700020305
3. Filippini T, Hatch EE, Rothman KJ, et al. Association between outdoor air pollution and childhood leukemia: a systematic review and dose-response meta-analysis. Environ Health Perspect. 2019;127(4):46002. doi:10.1289/EHP4381