Residential Exposure to Pesticide During Childhood and Childhood Cancers: A Meta-Analysis.

CONTEXT There is an increasing concern about chronic low-level pesticide exposure during childhood and its influence on childhood cancers. OBJECTIVE In this meta-analysis, we aimed to examine associations between residential childhood pesticide exposures and childhood cancers. DATA SOURCES We searched all observational studies published in PubMed before February 2014 and reviewed reference sections of articles derived from searches. STUDY SELECTION The literature search yielded 277 studies that met inclusion criteria. DATA EXTRACTION Sixteen studies were included in the meta-analysis. We calculated effect sizes and 95% confidence intervals (CIs) by using a random effect model with inverse variance weights. RESULTS We found that childhood exposure to indoor but not outdoor residential insecticides was associated with a significant increase in risk of childhood leukemia (odds ratio [OR] = 1.47; 95% CI, 1.26-1.72; I(2) = 30%) and childhood lymphomas (OR = 1.43; 95% CI, 1.15-1.78; I(2) = 0%). A significant increase in risk of leukemia was also associated with herbicide exposure (OR = 1.26; 95% CI, 1.10-1.44; I(2) = 0%). Also observed was a positive but not statistically significant association between childhood home pesticide or herbicide exposure and childhood brain tumors. LIMITATIONS The small number of studies included in the analysis represents a major limitation of the current analysis. CONCLUSIONS Results from this meta-analysis indicated that children exposed to indoor insecticides would have a higher risk of childhood hematopoietic cancers. Additional research is needed to confirm the association between residential indoor pesticide exposures and childhood cancers. Meanwhile, preventive measures should be considered to reduce children's exposure to pesticides at home.