Being overburdened and medically underserved: assessment of this double disparity for populations in the state of Maryland.

BACKGROUND: Environmental justice research has shown that many communities of color and low-income persons are differentially burdened by noxious land uses including Toxic Release Inventory (TRI) facilities. However, limited work has been performed to assess how these populations tend to be both overburdened and medically underserved. We explored this "double disparity" for the first time in Maryland. METHODS: We assessed spatial disparities in the distribution of TRI facilities in Maryland across varying levels of sociodemographic composition using 2010 US Census Health Professional Shortage Area (HPSA) data. Univariate and multivariate regression in addition to geographic information systems (GIS) were used to examine relationships between sociodemographic measures and location of TRI facilities. Buffer analysis was also used to assess spatial disparities. Four buffer categories included: 1) census tracts hosting one or more TRI facilities; 2) tracts located more than 0 and up to 0.5 km from the closest TRI facility; 3) tracts located more than 0.5 km and up to 1 km from a TRI facility; and 4) tracts located more than 1 km and up to 5 km from a TRI facility. RESULTS: We found that tracts with higher proportions of non-white residents and people living in poverty were more likely to be closer to TRI facilities. A significant increase in income was observed with an increase in distance between a census tract and the closest TRI facility. In general, percent non-white was higher in HPSA tracts that host at least one TRI facility than in non-HPSA tracts that host at least one TRI facility. Additionally, percent poverty, unemployment, less than high school education, and homes built pre-1950 were higher in HPSA tracts hosting TRI facilities than in non-HPSA tracts hosting TRI facilities. CONCLUSIONS: We found that people of color and low-income groups are differentially burdened by TRI facilities in Maryland. We also found that both low-income groups and persons without a high school education are both overburdened and medically underserved. The results of this study provide insight into how state agencies can better address the double disparity of disproportionate environmental hazards and limited access to health care resources facing vulnerable communities in Maryland.

Leaking Underground Storage Tanks and Environmental Injustice: Is There a Hidden and Unequal Threat to Public Health in South Carolina?

There are approximately 590,000 underground storage tanks (USTs) nationwide that store petroleum or hazardous substances. Many of these tanks are leaking, which may increase the risk of exposure to contaminants that promote health problems in host neighborhoods. Within this study, we assessed disparities in the spatial distribution of leaking underground storage tanks (LUSTs) based on socioeconomic status (SES) and race/ethnicity in South Carolina (SC). Chi-square tests were used to evaluate the difference in the proportion of populations who host a LUST compared to those not hosting a LUST for all sociodemographic factors. Linear regression models were applied to examine the association of distance to the nearest LUST with relevant sociodemographic measures. As percent black increased, the distance (both in kilometers and miles) to the nearest LUST decreased. Similar results were observed for percent poverty, unemployment, persons with less than a high school education, blacks in poverty, and whites in poverty. Furthermore, chi-square tests indicated that blacks or non-whites or people with low SES were more likely to live in LUST host areas than in non-host areas. As buffer distance increased, percent black and non-white decreased. SES variables demonstrated a similar inverse relationship. Overall, burden disparities exist in the distribution of LUSTs based on race/ethnicity and SES in SC.