A GI Science investigation into the relationship between childhood respiratory diseases and unhealthy ozone level: Environmental inequity and health disparities in the Houston area

A conceptual framework including the dose-response model, environmental inequity model, and health disparities model was proposed to study environmental health. The framework was used to investigate the triad relationships among the three components---ozone exceedances, childhood respiratory diseases prevalence, and socioeconomic status (SES)---in the highly polluted Houston area during the summer of 2001. The objective of the study is to illuminate the significance of environmental exposure and environmental inequity on health disparities. The study employs GIS and exploratory spatial data analysis (ESDA), to explore the spatial patterns of each component, and uses mapping and confirmatory spatial data analyses (CSDA) to examine the spatial associations between them. The results of ESDA reveal the existence of three local ozone highs, the locations and magnitudes of childhood respiratory disease hot spots, and the highly segregated socio-economic status in the Houston area. The results of CSDA show that there are significant spatial relationships at the local rather than the global scale. The areas of north-central, central, and southeast Houston contain the most significant spatial associations between ozone exceedances and disease prevalence. The north-central and southwest areas of Houston with a high percentage of low-income Hispanics have the most significant spatial associations between ozone exceedances and SES. The northeast, south-central and northwest areas of Houston with a high percentage of low-income African Americans have the most significant spatial association between disease prevalence and SES. Results show the consequence of health disparities of childhood respiratory diseases is not necessarily affected by the exposure to ozone exceedances. It indicates susceptibility may be a more important part than exposure for the health disparities of childhood respiratory diseases. The non-stionarity of the environmental inequity and health disparities suggests that GWR is an effective approach to identify the sub-regions affected by environment pollution and public health within an urban area. The areas identified as the high association of environmental inequity and health disparities may aid environmental regulatory agencies in resolving environmental health in air pollution through the regulation of new development.