Exposures from Oil and Gas Development and Childhood Leukemia Risk in Colorado: A Population-based Case-control Study

Background: Children living in upstream oil and natural gas (O&G) areas may be exposed to leukemogens and at increased risk for acute lymphocytic 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 age 2-9 years starting in 2002 to 2706 controls on birth month/year and Hispanic ethnicity. We estimated upstream O&G activity intensities from conception through a 10-year latency with 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% CL:0.964, 2.62), 84% (OR = 1.84, 95% CL: 1.35 -2.48) and 100% (OR = 2.00, 95% CL: 1.14 -3.37) increase in ALL risk for low, medium, and high IA-IDW groups, compared to the referent group. Within 13 km, we observed a 59% (OR= 1.59, 95% CL:1.03, 2.37), 40% (OR = 1.40, 95% CL: 1.09 -1.80) and 164% (OR = 2.64, 95% CL: 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.