Residential proximity to active and abandoned oil and gas development and risk of childhood Ewing sarcoma in California

Oil and gas development (OGD) has been linked to increased pediatric cancer risk, but the literature to date is focused on hematologic malignancies and active wells. The emergence of suspected clusters of cancers such as Ewing sarcoma in children living near OGD and widespread presence of abandoned wells warrants investigation. This study included 558 children born in California (1982–2015) reported to the California Cancer Registry with a diagnosis of Ewing sarcoma at 0–19 years (1988–2015), and 27,800 cancer-free controls frequency-matched to cases on birth-year (50:1 ratio). We used birth address to assign prenatal OGD exposure to active (drilled or producing) and plugged/abandoned wells separately with inverse distance-squared weighted well counts at 5 and 10 km buffer sizes from three months before conception to birth. We evaluated potential exposure disparities and estimated odds ratios (OR) and 95% confidence intervals (CI) for the association between prenatal OGD exposure and Ewing sarcoma risk using multivariable logistic regression. Hispanic children were significantly more likely to be exposed to both active and abandoned OGD within 10 km than non-Hispanics (40% vs. 23% and 14% vs. 6%, respectively). There were no associations between prenatal exposure to active OGD within 10 km and Ewing sarcoma risk (OR: 0.88 [95% CI: 0.72–1.08]). However, children within 10 km of abandoned wells were 1.27 [0.96–1.66] times as likely to develop Ewing sarcoma as unexposed children; when stratified by ethnicity, this association appeared in Hispanic children only (1.33 [0.95–1.88]). We did not identify an association between exposure to active OGD and pediatric Ewing sarcoma risk in California. Abandoned wells were associated with a suggestive increase in risk among Hispanic children, who were also more likely to be exposed to any OGD activity than non-Hispanic children. This disparity could have implications for other health outcomes including childhood cancers.