Exposure to traffic-related air pollution may be associated with an increased risk for childhood leukemia, according to a study published in Environment International. Christian Kreis, PhD, and colleagues investigated the link between traffic-related air pollution and the risk for childhood cancer in patients younger than 16. The analysis included 2,960 incident cases of childhood cancer identified from a childhood cancer registry (1990-2015) and probabilistically linked cases with a census-based national cohort study. For exposure to nitrogen dioxide per 10 μg/m3, the adjusted HRs were 1.00 (95% CI, 0.88-1.13) for acute lymphoblastic leukemia (ALL) and 1.31 (95% CI, 1.00-1.71) for acute myeloid leukemia (AML). The effect for AML was attenuated when using a 1- to 5-year exposure lag instead of current exposure. For exposure to benzene per 1 μg/m3, the adjusted HR was 1.03 (95% CI, 0.86-1.23) for ALL and 1.29 (95% CI, 0.86-1.95) for AML. Increased HRs were detected for non-Hodgkin lymphoma as well.