BACKGROUND/OBJECTIVES: Due to increasing concerns over the impact of traffic-related air pollution on childhood cancers, we evaluated residential proximity to major roadways and risk for developing a childhood central nervous system (CNS) tumor in Texas.
DESIGN/METHODS: We obtained information on all children diagnosed with a CNS tumor at <5 years of age and born in Texas (USA) during the period of 2003-2009 (n=315) from the Texas Cancer Registry. A random sample of birth certificate controls was frequency matched to cases (5:1) on birth year (n=1,575). Based on the maternal residence at the time of the child’s birth, we assessed exposures to traffic-related air pollution using residential proximity to major roadways derived from Geographic Information System (GIS) applications. Logistic regression was used to generate odds ratios (OR) and 95% confidence intervals (CI) adjusted for the child’s sex and year of birth, maternal education and race/ethnicity, and area-level poverty. We evaluated CNS tumors as a group and by histologic type (e.g., ependymoma, primitive neuroectodermal tumor [PNET]).
RESULTS: Maternal residential proximity to major roadways during pregnancy was statistically significantly associated with CNS tumor risk in offspring. Specifically, risk increased by 30% for every kilometer [km] closer to a major roadway (OR [95% CI]: 1.3 [1.0-1.7]). Moreover, mothers who lived in areas of high roadway density (>1.5-km length of major road segments within a 500-m residential radius) were 1.5-times more likely (95% CI: 1.1-2.1) and 4.2-times more likely (95% CI: 1.2-14.9) to have offspring with any CNS tumor and ependymomas, respectively, when compared mothers in low density areas.
CONCLUSION: In this large population-based assessment, we found that mothers who live close to major roadways or who live in areas of high roadway density were more likely to have offspring who develop a CNS tumor, particularly an ependymoma.
