Table 1.

Overview of community based projects involving quantification of cumulative risk.

Study & Topics	Purpose or Problem	Study Design	Primary Findings
Sadd et al., (2011) [3] Air and Social Environment	Development of the Environmental Justice Screening Method (EJSM) to Examined the relative rank of cumulative impacts and social vulnerability within metropolitan regions.	EJSM uses 23 health, environmental and social vulnerability measures organized along three categories: (1) hazard proximity and land use; (2) estimated air pollution exposure and health risk; and (3) social and health vulnerability in the Los Angeles area.	Areas with high hazard proximity and sensitive land use scores correspond to Areas with high hazard proximity and sensitive land use scores corresponded with dense populations and major industrial centers or transportation corridors. Health risk and exposure scores had little fine-scale variation and broad areas with a single score. Cumulative impact (CI) scores were normally distributed, with highest scores corresponding to communities near ports and airports.
Clougherty et al., (2007) [19] Air, Social Environment, and Health Impacts	Examined the role of exposure to violence (ETV), a chronic stressor, in altering susceptibility to traffic-related air pollution in asthma etiology.	GIS-based models estimated residential exposures to traffic-related pollution for 413 children in East Boston, MA, between 1987 and 1993, using monthly NO2 measurements for 13 sites over 18 years. Pollution estimates were merged with questionnaire data on lifetime exposure to violence, and effects of both on childhood asthma etiology were examined.	Found elevated risk of asthma with a one standard deviation (4.3 ppb) increase in NO2 exposure among children with above-median ETV (odds ratio = 1.63; 95% confidence interval = 1.14–2.33). Demonstrated an association between traffic-related air pollution and asthma solely among urban children exposed to violence.
Clougherty and Kubzansky (2009) [20] Health Impacts and Social Environment	Synthesized relevant research from social and environmental epidemiology, toxicology, immunology, and exposure assessment to provide a framework for environmental health researchers aiming to investigate health effects of environmental pollution combined with social or psychological factors.	Reviewed existing epidemiologic and toxicological evidence on synergistic effects of stress and pollution.	Described Physiologic effects of stress. Addressed key issues related to measuring and evaluating stress as it relates to physical environmental exposures and sus­ceptibility.
Brody et al., (2009) [21] Air and Health Impacts	Tested for chemical markers of oil refinery emissions in homes; characterized cumulative effects of emissions in an EJ community by measuring a large and diverse set of pollutants from outdoor and indoor sources; assessed geographic and sociodemographic differences in endocrine disrupting compound (EDC) exposures.	The investigators analyzed indoor and outdoor air from 40 homes in industrial Richmond, CA, and 10 in rural Bolinas, CA, for 153 compounds, including particulates and endocrine disruptors.	Detected eighty outdoor compounds in Richmond and 60 in Bolinas; Richmond concentrations were generally higher, due to heavy oil combustion from oil refining and shipping. Paired outdoor-indoor measurements were correlated to industry- and traffic-related pollutants. Indoor air quality is an important indicator of the cumulative impact of outdoor emissions in fence-line communities.
Morello-Frosch and Shenassa (2006) [22] Psychosocial Stressors and Environmental Hazards	Presented evidence that individual-level and place-based psychosocial stressors may combine with environmental pollutants and have adverse health effects, explaining maternal and child health (MCH) disparities.	Proposed a conceptual framework for holistic approaches to future MCH research that elucidates the interplay of psychosocial stressors and environmental hazards to better explain drivers of MCH disparities.	Suggested that a holistic approach to future MCH research that seeks to untangle the double jeopardy of chronic stressors and environmental hazard exposures could help elucidate how the interplay of these factors shapes persistent racial and economic disparities in MCH.
Su et al., (2009) [23] Air and Social Environment	Proposes an index to assess cumulative environmental hazard inequalities in socially disadvantaged groups and neighborhoods in the Los Angeles region of California.	Extended the concentration index to summarize inequality in the distribution of multiple pollutants across socioeconomic and racial/ethnic groups. Index used population ranked by area-based racial, ethnic or socioeconomic composition, and the cumulative environmental hazard, aggregated with various weighting functions.	Analyzed single and cumulative environmental inequalities in exposure to NO2, PM2.5 and diesel PM; cancer risk; poverty measures; and racial/ethnic population composition. Environmental inequality curves were significantly different from the equality line. Demonstrated that environmental inequalities exist for non-white populations as well as for poorer populations in Los Angeles.
Fox et al., (2002) [24] Health Impacts	Advanced CRA methods and tested their application in a community case study. Cumulative risk and health assessments were compared for south and southwest Philadelphia communities.	Obtained mortality data by from the city of Philadelphia, using deaths for 1990 ( n = 3151) and for 1988–1992 (n = 16,168). Used air pollutant data for all census tracts as a proxy for human exposure. Conducted cumulative risk scoring using two toxicological databases, a multi-end point toxicological database and the EPA Cumulative Exposure Toxicity Database (CETDB).	Analysis found correlations between cumulative risk and mortality measurements for whites and non-whites when risk when using the multi-end point toxicological database. Statistically significant increases in total and respiratory mortality were associated with increases in cumulative risk scores. Regression analyses that controlled for percent non-white population and per capita income indicated that environmental effects on health were independent of race and income.
Krieg and Faber (2004) [25] Toxic Sites	The EJ literature is characterized by a failure to measure overall impact from an extensive range of ecological hazards effectively. Limitations on available data make this a serious problem for present and future studies.	Developed and implemented a cumulative measure of negative environmental impacts by controlling for the density and severity of ecological hazardous sites and facilities within every community in the state.	Found that exposure patterns take a generally linear distribution when analyzed by race and class. Findings suggest that environmental injustice existed on a consistent continuum for nearly all communities.