Grantee Research Project Results
2011 Progress Report: Hypertension in Mexican-Americans: Assessing Disparities in Air Pollutant Risks
EPA Grant Number: R834581Title: Hypertension in Mexican-Americans: Assessing Disparities in Air Pollutant Risks
Investigators: Symanski, Elaine , Piller, Linda B. , Fernandez-Esquer, Maria E. , Bondy, Melissa L. , Chen, Lin-An , Chan, Wenyaw
Current Investigators: Symanski, Elaine , Bondy, Melissa L. , Chen, Lin-An , Jimenez, Maria , Strom, Sara , Chan, Wenyaw
Institution: The University of Texas School of Public Health , The University of Texas MD Anderson Cancer Center , National Chiao-Tung University
Current Institution: The University of Texas School of Public Health , National Chiao-Tung University , The University of Texas MD Anderson Cancer Center
EPA Project Officer: Hahn, Intaek
Project Period: August 1, 2010 through July 31, 2014 (Extended to July 31, 2016)
Project Period Covered by this Report: August 1, 2010 through July 31,2011
Project Amount: $1,250,000
RFA: Understanding the Role of Nonchemical Stressors and Developing Analytic Methods for Cumulative Risk Assessments (2009) RFA Text | Recipients Lists
Research Category: Human Health
Objective:
In this project, we are assessing the hypothesis that individual- and neighborhood-level psychosocial stressors exacerbate risks for hypertension associated with fine particulates and other air pollutants among individuals of Mexican origin living in Houston, Texas, who also are participating in the University of Texas M.D. Anderson Cancer Center's Mano a Mano cohort study. Several studies have shown an association between air pollutants and hypertension via oxidative stress and inflammatory pathways. Yet, little is known about the modifying effects of nonchemical stressors on air pollutant risks for hypertension. Incidences of hypertension, a key risk factor for cardiovascular diseases (CVD), have been growing in the United States (U.S.) and CVD remains the leading cause of death among the U.S. Hispanic population. Novel methods for addressing interactions in a logistic regression context are being developed. We also are developing a community-based approach by involving the community in defining research questions, identifying mechanisms for becoming involved in research activities and interpreting and disseminating research findings. This program also will help to identify culturally specific elements that could be used for an effective intervention in a Latino community to address disparities in air pollutant health risks.
Progress Summary:
Our progress is summarized below.
(1) In our development of statistical methods, we have begun to examine how different methods of dichotomizing a continuous outcome affect the interpretation of the interaction term of a binary regression model by deriving the natural link function for several dichotomization methods on the support of the continuous outcome variable. We also borrowed the concept of "isobole" in toxicology to define the interaction and examined, from a statistical perspective, additive, antagonistic and synergistic effects.
(2) Work has been initiated to write computer code to perform simulations for examining the models associated with these link functions and to compare them to the corresponding models that include an interaction term.
(3) Community involvement in the research project was established through participation and reporting of the progress of our work to the Mano-a-Mano Community Advisory Board and the formation of an advisory group for the project, the Neighborhood Council of Advisors, with whom we have met twice. Focus groups of neighborhood residents were conducted to learn about sources of stress that community members experience at work, at home and in their neighborhoods, along with activities and behaviors that may influence exposures to air pollution. The residents were divided by sex and language preference (Spanish or English). These conversations have been transcribed and translated (if necessary) and currently are being evaluated.
(4) Annual traffic count data and roadway network data also have been obtained to facilitate the development of the air pollution metrics. Additionally, we obtained data about facilities in the study area that emit PM2.5 through the EPA's AirData database to allow for developing a metric for proximity metric to major industrial point sources.
Future Activities:
(1) During the subsequent reporting period, we will complete our evaluation of the focus group discussions. We will develop and pilot test the questionnaire among selected members of the Mano-a-Mano cohort.
(2) Upon receiving feedback from the pilot testing, the survey will be refined to be administered to cohort members who agree to participate in our study.
(3) Regarding statistical methodology, we plan to examine the properties of additive, antagonistic and synergistic effects on our statistical definition of isobole and their relationships with the interaction term in a binary regression model.
(4) We will implement the methods proposed in our grant application for comparisons with these effects. The comparisons will be performed mathematically and empirically. We also plan to illustrate the application of the developed methods using Mano-a-Mano data.
Journal Articles:
No journal articles submitted with this report: View all 5 publications for this projectSupplemental Keywords:
Air pollution, epidemiology, exposure, sensitive populations, Health, Scientific Discipline, ENVIRONMENTAL MANAGEMENT, Risk Management, Health Risk Assessment, Risk Assessments, Biochemistry, Biology, cumulative exposure, cumulative risk, hypertension, air pollution, latino community, sensitive subjects, hispanics, cardiovascular disease, human health riskProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.
Project Research Results
- Final Report
- 2015 Progress Report
- 2014 Progress Report
- 2013 Progress Report
- 2012 Progress Report
- Original Abstract
3 journal articles for this project