PM2.5, vegetation density, and childhood cancer: a case-control registry-based study from Texas 1995-2011
Menée au Texas à partir de données 1995-2011 portant sur 109 762 témoins et 6 101 patients atteints d'un cancer pédiatrique (âge : 0-16 ans), cette étude analyse l'association entre une exposition aux particules fines (PM2,5), l'indice de végétation et le risque de développer la maladie
Air pollution is positively associated with some childhood cancers while greenness is inversely associated with some adult cancers. The interplay between air pollution and greenness in childhood cancer etiology is unclear. We estimated the association between early life air pollution and greenness exposure and childhood cancer in Texas (1995-2011).We included 6,101 cancer cases and 109,762 controls (aged 0-16 years). We linked residential birth address to census tract annual average particulate matter ≤2.5 µg/m³ (PM2.5) and Normalized Difference Vegetation Index (NDVI). We estimated odds ratios (OR) and 95% confidence intervals (95% CI) between PM2.5/NDVI interquartile range increases and cancer. We assessed statistical interaction between PM2.5 and NDVI (likelihood ratio tests).Increasing residential early life PM2.5 exposure was associated with all childhood cancers (OR 1.10, 95% CI: 1.06-1.15), lymphoid leukemias (OR: 1.15, 95% CI: 1.07-1.23), Hodgkin lymphomas (OR: 1.27, 95% CI: 1.02-1.58), non-Hodgkin lymphomas (OR: 1.24, 95% CI: 1.02-1.51), ependymoma (OR: 1.27, 95% CI: 1.01-1.60) and others. Increasing NDVI exposure was inversely associated with ependymoma (0-4-year-old OR: 0.75, 95% CI: 0.58-0.97) and medulloblastoma (OR: 0.75, 95% CI: 0.62-0.91), but positively associated with malignant melanoma (OR: 1.75, 95% CI: 1.23-2.47) and Langerhans cell histiocytosis (OR: 1.56, 95% CI: 1.07-2.28). There was evidence of statistical interaction between NDVI and PM2.5 (p < .04) for all cancers.Increasing early life exposure to PM2.5 increased the risk of childhood cancers. NDVI decreased risk of two cancers yet increased risk of others. These findings highlight the complexity between PM2.5 and NDVI in cancer etiology.