Abstract
BACKGROUND: Children living in upstream oil and natural gas (O&G) areas may be exposed to leukemogens and at increased risk for acute lymphoblastic leukemia (ALL). METHODS: We conducted a case-control study of children born in Colorado between 1992 and 2019. We matched 451 children diagnosed with ALL at ages 2 to 9 years starting in 2002 to 2,706 controls based on birth month/year and Hispanic ethnicity. We estimated upstream O&G activity intensities from conception through a 10-year latency using our intensity-adjusted inverse distance weighted (IA-IDW) model. We applied logistic regression models adjusted for confounders to evaluate associations between ALL and IA-IDW. RESULTS: For children within 5 km of an O&G well site, we observed a 62% [OR = 1.62; 95% confidence interval (CI), 0.964-2.62], 84% (OR = 1.84; 95% CI, 1.35-2.48), and 100% (OR = 2.00; 95% CI, 1.14-3.37) increase in ALL risk for low, medium, and high IA-IDW groups, compared with the referent group. Within 13 km, we observed a 59% (OR = 1.59; 95% CI, 1.03-2.37), 40% (OR = 1.40; 95% CI, 1.09-1.80), and 164% (OR = 2.64; 95% CI, 1.80-3.86) increase in ALL risk for low, medium, and high IA-IDW groups. CONCLUSIONS: Colorado's children living within 13 km of O&G well sites are at increased risk for ALL, with children within 5 km bearing the greatest risk. Current setbacks between O&G well sites and residences may not be sufficient to protect the health of these children. IMPACT: Our results can be applied to policies to reduce childhood leukemogen exposures.