EXPLORING RISK ASSESSMENT METHODS TO EXAMINE NEUROLOGICAL RISK DUE TO AIR TOXIC EXPOSURE IN MINNESOTA

Abstract

BackgroundExisting research has investigated the relationships between sociodemographic characteristics and air toxic exposure in the United States. However, a few studies have examined the neurological risk from exposure to air toxics. The purpose of the study was to determine the correlation between sociodemographic variables and neurological risk due to exposure to air toxics. Also, spatial meth-ods were used to understand the distribution of neurological risk and sociodemographic character-istics. Methods Air toxic neurological risk data were obtained from the United States Environmental Protection Agency's National-scale Air Toxics Assessment and sociodemographic data from the 2010-2014 American Community Survey US Census Bureau. The NATA dataset contains 24 neurotoxic air pollutants. The hazard quotient (HQ) for each air pollutant was quantified by calculating the ratio of the inhalation exposure concentration (EC) to the reference concentration (RfC). In addition, the EPA additively models the neurological risks of different pollutants (HQ) to estimate an aggregate neurological risk score (hazard index (HI)) for each census tract. We conducted statistical analysis using R and spatial analysis using ArcGIS 10. Results The mean cumulative neurological risk (HI) from all sources was 0.05, and all HI<1 for all tracts in Minnesota. The range of values for HI is 1 to >1, with >1 being the greatest harm. Percent pov-erty, percent without high school education and percent non-Hispanic white were weakly negative-ly correlated with cumulative neurological risk. In comparison, median household income, percent unemployed, percent non-Hispanic black, percent Hispanic and percent people of color were weak-ly positively correlated with cumulative neurological risk. The choropleth map of cumulative neuro-logical risk showed that individuals in Minneapolis-St. Paul may be disproportionately exposed to air toxics. Conclusions These findings suggest that there may be an unequal distribution of neurotoxic air pollutants, espe-cially in Minneapolis-St. Paul. Study results may inform and target public health efforts at specific locations to eliminate sociodemographic inequalities in exposure to neurotoxic air pollutants.