ARB Research Seminar

This page updated January 21, 2020

Improving the CalEnviroScreen Score at the US-Mexico Border

Photo of Penelope J.E. Quintana, Ph.D., MPH

Penelope J.E. Quintana, Ph.D., MPH

Photo of Atsushi Nara, Ph.D.

Atsushi Nara, Ph.D.

Photo of Miguel Zavala, Ph.D.

Miguel Zavala, Ph.D.

Penelope J.E. Quintana, Ph.D., MPH, Atsushi Nara, Ph.D., Miguel Zavala, Ph.D.

February 13, 2020
Cal EPA Headquarters, 1001 "I" Street, Sacramento, CA

Research Project


CalEnviroScreen (CES) is a screening tool developed by the California Environmental Protection Agency that scores California census tracts based on measurements of pollution burden and population vulnerability in order to direct resources toward improving public health in disadvantaged and burdened communities. Communities near the U.S.-Mexico border face pollution burdens from sources in Baja California that are not fully incorporated into CalEnviroScreen. To improve the understanding of impacts of air pollution from Mexico on border communities and provide critical data to the California Air Resources Board, Dr. Quintana and colleagues carried out three types of analysis. The first was mapping activities for sources in Baja California, including burn events; the second was modeling the potential areas of influence of selected sources and potential source regions for California communities; and the third was to estimate the impact of sources close to the border on existing community scores in the Environmental Justice Screening Model. A systematic methodology was developed that included satellite imagery and ground-based verification of locations of sources, and a database that contains 1174 facilities was created for use in this and future projects.

Modeling results strongly suggest that areas in the US immediately adjacent to the border and farther north in San Diego and Imperial counties are likely to be affected by emission sources on the Mexican side, not only within a 1.5-km radius from the border but also from potential regions both inland and off-shore within a 50-km range. A pilot method was developed for measuring and mapping fire activity near the US-Mexico border, and the investigators will present mapped locations and temporal patterns of agricultural burning on both sides of the border. Data also indicated that urban burning was common in Mexicali. Air toxics emissions sources in Mexico have a clear potential to affect communities and individuals in the US-Mexico border region. Recommendations include using the tools developed in this analysis to determine border-specific approaches to incorporating sources in Baja California in the CalEnviroScreen score.

Speaker Biographies

Dr. Quintana received a Bachelor of Science degree in Genetics from the University of California, Davis, a Master of Public Health in Occupational and Environmental Health from San Diego State University, and a PhD in Environmental Health Sciences from the University of California, Berkeley. She is a Professor in the Division of Environmental Health at the School of Public Health at San Diego State University, and her research focuses on exposures to children and vulnerable populations at the US-Mexico border. Dr. Quintana has assessed children's exposure to toxicants in house dust and on surfaces, especially residual tobacco toxicants remaining after smoking has taken place, known as thirdhand smoke. In conjunction with researchers at Universidad Autónoma de Baja California, Tijuana, she has studied exposure to toxic traffic pollutants inside vehicles and exposures to pedestrians waiting in lines to cross the US-Mexico border. Additionally, she supports US-Mexico border community efforts to monitor their air through deployment of low-cost air sensors in the San Ysidro Air Monitoring Network and the Tijuana-based San Ysidro Port-Of-Entry Community Air Study. Dr. Quintana is the author of a report drawing attention to the long northbound wait times and lines of idling vehicles at US-Mexico Ports of Entry as an environmental justice issue for border crossers and surrounding communities. She is a Scientific Guidance Panel member for the California Environmental Contaminant Biomonitoring Program.

Dr. Nara received a Bachelor of Science degree in Environmental Engineering from Shimane University, Shimane, Japan, a Master of Science in Geography from University of Utah, and a PhD in Geography from Arizona State University. Dr. Nara is Associate Professor in Department of Geography, San Diego State University. Dr. Nara is also an Associate Director of Center for Human Dynamics in the Mobile Age. His research interests are in Geographic Information Science, spatiotemporal data analytics, geo-computation approaches, agent-based modeling and complex adaptive systems, applied to study human mobility, urban dynamics, and interdisciplinary fields. In recent years, he has applied GIScience and geo-computation for: supporting spatial decisions under emergency evacuation; identifying strategies to build capacity for geo-computational thinking in preK-14 education; examining spatial disparities in public health and cancer epidemiology; and understanding the impacts of air pollution in the California-Mexico border region.

Dr. Zavala is a Research Scientist at the Molina Center for Strategic Studies in Energy and the Environment (MCE2) with over 12 years of experience in data analysis of ambient measurements and modeling of physicochemical processes of air pollution and climate change. His research interests include the development of methods for assessing the impacts of air pollution at local and regional scales. Dr. Zavala holds a M.Sc. in Environmental Sciences from the Tecnológico de Monterrey and a Ph.D. in Atmospheric Sciences from the Massachusetts Institute of Technology.

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