Geospatial Distribution of Age-adjusted Incidence of the Three Major
Types of Pediatric Cancers and Waterborne Agrichemicals in Nebraska
Abstract
This study was conducted to examine, at the county level, the
relationship between pediatric cancers incidence rate and atrazine and
nitrate mean concentrations in surface and groundwater. A negative
binomial regression analysis was performed to investigate the
association between central nervous system (CNS) tumors, leukemia,
lymphoma, and atrazine and nitrate mean concentrations in surface and
groundwater. The age-adjusted brain and other CNS cancers incidence was
higher than the national average in 63% of the Nebraska counties. After
controlling for nitrate concentrations in surface and groundwater,
counties with atrazine concentrations between 0.95 - 2.82 µg/L in both
surface and groundwater had a higher incidence rate for pediatric
cancers (brain and other CNS, leukemia, and lymphoma) compared to
counties with surface and groundwater atrazine concentrations in the
reference group (0.00 - 0.13 µg/L). Additionally, compared to counties
with groundwater nitrate concentrations between 0 and 2 mg/L (reference
group), counties with groundwater nitrate concentrations between 2.1 and
5 mg/L (group 2) had a higher incidence rate for pediatric brain and
other CNS cancers (IRR=13.25; 95% CI: 13.00-13.50), leukemia (IRR=6.13;
95% CI: 6.02-6.26), and lymphoma (IRR=11.53; 95% CI: 11.32-11.75)
after adjusting for all covariates in the model. While these findings do
not indicate a causal relationship, they suggest that atrazine and
nitrate may pose a significant risk relative to the genesis of pediatric
brain and CNS cancers, leukemia, and lymphoma.