Pesticides are a potential risk factor for childhood leukemia. Studies evaluating the role of prenatal and/or early life exposure to pesticides in the development of childhood leukemia have produced a range of results. In addition to indoor use of pesticides, higher risks have been reported for children born near agricultural crops. No studies have looked at pesticide exposure based on proximity of birth residence to commercial plant nurseries, even though nurseries are located much closer to residences than agricultural crops and can potentially result in chronic year-round pesticide exposure. To evaluate whether risk of childhood leukemia is associated with pesticide use as determined by distance of residence at birth to commercial, outdoor plant nurseries. We conducted a large statewide, record-based case-control study of childhood leukemia in California, which included 5788 childhood leukemia cases and an equal number of controls. Pesticide exposure was based on a spatial proximity model, which combined geographic information system data with aerial satellite imagery. Overall, the results supported an increased childhood leukemia risk only for birth residences very close to nurseries. For birth residences less than 75 m from plant nurseries, we found an increased risk of childhood leukemia (odds ratio (OR) 2.40, 95% confidence interval (CI) 0.99-5.82) that was stronger for acute lymphocytic leukemia (OR 3.09, 95% CI 1.14-8.34). The association was robust to choices of reference group, cut points and data quality. Our findings suggest that close proximity to plant nurseries may be a risk factor for childhood leukemia and that this relationship should be further evaluated.

Little is known about occupational SARS-CoV-2 exposures and COVID-19 outcomes. We established a Doctor’s First Reports of Occupational Injury or Illness (DFR)-based surveillance system to study cases of work-related COVID-19 exposures and disease. The surveillance data included demographics, occupation, industry, exposure, and illness, details including hospitalization and lost work. We classified workers into ‘healthcare’, non-healthcare ‘public-facing’, or ‘other’ worker groups, and rural–urban commuting areas (RUCAs). We describe worker exposures and outcomes overall by worker group and RUCA. We analyzed 2848 COVID-19 DFRs representing workers in 22 detailed occupation groups and 19 industry groups. Most DFRs were for workers in metropolitan RUCAs (89%) and those in healthcare (42%) and public-facing (24%) worker groups. While DFRs were from 382 unique worksites, 52% were from four hospitals and one prison. Among 1063 DFRs with a suspected exposure, 73% suspected exposure to a patient or client. Few DFRs indicated hospitalization (3.9%); however, the proportion hospitalized was higher among nonmetropolitan (7.4%) and public-facing (6.7%) workers. While 56% of DFRs indicated some lost work time, the proportion was highest among public-facing (80%) workers. Healthcare and prison workers were the majority of reported occupational COVID-19 exposures and illnesses. The risk of COVID-19 hospitalization and lost work may be highest among nonmetropolitan and public-facing workers.