Environmental Justice Screening Method (EJSM)

Despite the landmark victory in 1994 in which President Clinton signed an Executive Order directing every federal agency to identify and rectify “disproportionately high and adverse human health or environmental effects of its programs, policies, and activities on minority populations and low-income populations,” disparities in health status by race and income persist and were identified as a top public health priority in Healthy People 2010.

While these disparities have many different causes, it is probable that differences in exposure to environmental hazards play an important role. Until recently, a major challenge faced by policy makers—who have historically taken a facility-by-facility, chemical-by-chemical approach to regulation—was the lack of a methodology to assess the cumulative impact of environmental hazards in a more holistic way, and one that also addresses the patterns of environmental inequality.

Starting in 2007, Rachel Morello-Frosch of UC Berkeley, Manuel Pastor of USC, and James Sadd of Occidental College sought to meet this challenge by working directly with communities to develop the Environmental Justice Screening Method (EJSM). Now in its third iteration, it is a relatively simple, flexible, and transparent mapping and scoring procedure to examine cumulative impacts and social vulnerability within California regions for use in citing, zoning, and policy development processes as well as to identify overburdened communities.

An initial version of it was created for the California Air Resources Board and assesses cumulative impact along three dimensions: hazard proximity and land use, air pollution exposure and estimated health risk, and social and health vulnerability. In recent years, the EJSM has incorporated a fourth layer—climate change vulnerability—as well as expanded coverage to all of California. Continued work on the EJSM seeks to update the results with new releases of underlying indicators, expand coverage to other states, and incorporate new indicators including water quality and system-level vulnerability.

Since its creation, the EJSM has become part of a growing family of screening methods. In California, the state’s Office of Environmental Health Hazard Assessment created CalEnviroScreen 2.0 (CES)—the tool being used to identify “disadvantaged communities” in which 25 percent of California’s cap-and-trade revenue will be invested pursuant of SB 535—and UC Davis Center for Regional Change developed the Cumulative Environmental Vulnerabilities Assessment (CEVA) focusing on the San Joaquin Valley.



The Truth, the Whole Truth, and Nothing but the Ground-truth: Methods to Advance Environmental Justice and Researcher-Community Partnerships

By James Sadd, Rachel Morello-Frosch, Manuel Pastor, Martha Matsuoka, Michele Prichard, and Vanessa Carter

Health Education & Behavior 2014, Vol. 4(3) 281-290.

Environmental justice advocates often argue that environmental hazards and their health effects vary by neighborhood, income, and race. To assess these patterns and advance preventive policy, their colleagues in the research world often use complex and methodologically sophisticated statistical and geospatial techniques. One way to bridge the gap between the technical work and the expert knowledge of local residents is through community-based participatory research strategies.

In this article, the authors document how an environmental justice screening method was coupled with "ground-truthing"—a project in which community members worked with researchers to collect data across six Los Angeles neighborhoods—which demonstrated the clustering of potentially hazardous facilities, high levels of air pollution, and elevated health risks. They provide recommendations and implications for future research and collaborations between researchers and community-based organizations.

Read article >>

Screening for Justice: Proactive Spatial Approaches to Environmental Disparities

By Manuel Pastor, Rachel Morello-Frosch, and Jim Sadd

Whether it’s proximity to mobile and stationary emission sources, poor ambient air quality, or the relationship between air toxics and student demographics at the school site, researchers studying issues of environmental justice in California have generally found consistent evidence of significant disparities in exposure by racial and socioeconomic factors (including indicators like income, rates of home ownership, and linguistic isolation), even after controlling for land use and other explanatory factors.

This article appears in the August 2013 issue of EM Magazine, a publication of the Air & Waste Management Association (A&WMA; www.awma.org). To obtain copies and reprints, please contact A&WMA directly at 1-412-232-3444.


PERE and Affiliate Researchers release article in the International Journal of Environmental Research and Public Health

“Playing It Safe: Assessing Cumulative Impact and Social Vulnerability through an Environmental Justice Screening Method in the South Coast Air Basin, California”

By James L. Sadd, Manuel Pastor, Rachel Morello-Frosch, Justin Scoggins, and Bill Jesdale

Read the article here >>

EJSM Resources

  • EJSM Maps Packet
    This packet contains maps for each of the eight EJSM regions (which cover all of California). The maps show Cumulative Impact (CI) scores as well as scores for the four individual component layers—hazard proximity, health risks and exposure, social vulnerability, and climate change vulnerability.
    January 2015

  • Comparing Screening Methods
    This handout compares  metrics and methods used in three of California’s screening methods: EJSM, CalEnviroScreen 2.0 (CES), and the Cumulative Environmental Vulnerabilities Assessment (CEVA).
    Updated August 2015



Recent EJSM Presentations

January 16, 2015

Environmental Justice Screening Method Convening Presentation

By Rachel Morello-Frosch, Manuel Pastor, James Sadd, and Madeline Wander


May 13, 2015

Environmental Justice Screening Method Webinar

An this webinar hosted by PERE with the California Air Resources Board (CARB), we presented the Environmental Justice Screening Method version 3.0 and highlighted: recent methodological improvements to the EJSM, new approaches to gauging and improving data accuracy, and the incorporation of new data on climate change vulnerability and drinking water quality.





  • Program for Environmental and Regional Equity (PERE)
  • 950 W. Jefferson Blvd., JEF 102
  • Los Angeles, CA 90089-1291