Online Program

330943
Estimating exposures to airborne particulate matter and ozone in understudied US populations: Environmental justice applications of downscaled numerical model output


Tuesday, November 3, 2015 : 8:50 a.m. - 9:10 a.m.

Mercedes Bravo, Ph.D., Children's Environmental Health Initiative, School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI
Rebecca Anthopolos, MA, School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI
Michelle Bell, Ph.D., School of Forestry and Environmental Studies, Yale University, New Haven, CT
Marie Lynn Miranda, PhD, School of Natural Resources & Environment, University of Michigan, Ann Arbor, MI
Some US populations may be disproportionately exposed to harmful air pollutants, such as particulate matter with an aerodynamic diameter <2.5µm (PM2.5) and ozone (O3). Previous work examining air pollution exposure burdens relies heavily on ambient monitoring data, limiting investigations to populations close to monitors. We estimate exposures to PM2.5 and O3 for previously unstudied populations by utilizing Community Multi-scale Air Quality (CMAQ) model downscaler output.

Our objective was to estimate whether and to what extent subpopulations experience disproportionate exposures to PM2.5 and O3. Using downscaler-derived concentration estimates, we estimated average exposure to PM2.5 and O3 for US Census tracts (n=52,778) from 2002-2006. We assessed population-weighted exposures by population subgroup (e.g., urbanicity, race/ethnicity, education); used a local spatial measure of racial residential segregation (RRS) to discern whether more and less segregated tracts had different average exposures; and evaluated demographic characteristics in tracts with the highest (>80th percentile) and lowest (<20th percentile) long-term pollution levels.

Tracts with higher percentages of non-Hispanic blacks/African Americans (NHB) and Hispanics and higher unemployment, poverty, and urbanicity were more likely to have a PM2.5 monitor (p<0.05). Tracts more likely to have O3 monitors were more rural, with more non-Hispanic whites (NHW). Tracts with the highest average PM2.5 levels were more urban (99.7% vs. 90.9% urban) and had more NHBs (23.6% vs. 5.80%) compared to tracts with the lowest PM2.5 concentrations. Populations in tracts with the highest O3 concentrations were more rural (63.1% vs. 99.7% urban) and had more NHWs (72.2% vs. 53.6%) than tracts with the lowest O3 levels. More segregated tracts (i.e., those with high RRS score for NHBs) have higher average PM2.5 concentrations than less segregated tracts. Findings indicate that racial and urban/rural disparities exist in long-term exposures to PM2.5 and O3, and that more racially segregated areas may have higher average air pollution levels.

Learning Areas:

Environmental health sciences
Epidemiology
Public health or related research

Learning Objectives:
Assess whether subpopulations experience disproportionate exposures to particulate matter with an aerodynamic diameter <2.5┬Ám (PM2.5) and ozone O3) Evaluate to what extent subpopulations experience disproportionate exposures to PM2.5 and O3

Keyword(s): Environmental Health, Environmental Justice

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I completed my Ph.D. in 2014. My dissertation topic was exposure to air pollution and susceptibility/vulnerability in different population subgroups, which is directly relevant to the material in this abstract. I have over 7 years of experience in the environmental health and epidemiology field and have published several peer-reviewed journal articles on the topics of exposure assessment and health effects of ambient air pollution.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.