Grantee Research Project Results
Final Report: Development and Validation of the Cumulative Environmental Exposure Index for Arsenic: A Novel Environmental Public Health Indicator
EPA Grant Number: R834794Title: Development and Validation of the Cumulative Environmental Exposure Index for Arsenic: A Novel Environmental Public Health Indicator
Investigators: O'Bryant, Sid E. , Mulligan, Kevin R. , Gong, Gordon , Zhang, Yan
Institution: Texas Tech University Health Sciences Center
EPA Project Officer: Hahn, Intaek
Project Period: March 1, 2011 through February 28, 2013 (Extended to February 28, 2014)
Project Amount: $482,900
RFA: Exploring Linkages Between Health Outcomes and Environmental Hazards, Exposures, and Interventions for Public Health Tracking and Risk Management (2009) RFA Text | Recipients Lists
Research Category: Human Health
Objective:
The purpose of this project was to develop and validate a cumulative environmental exposure index for arsenic (As) using both GIS-based and direct observational methods, which were to be linked to health outcomes of rural and urban dwelling adults and elders. Over the course of this grant, we successfully enrolled 600 participants from both rural and urban-dwelling settings (ages 40 and above). However, we have enrolled more than 600 participants into the GIS-based As component. We conducted GIS-based As calculations (current and cumulative at current household) for 400 rural-dwelling participants and completed direct measurements of groundwater As among 200 of those participants for validation of the GIS-based modeling. We have calculated the CEEI-As index at current household for each of these participants by multiplying current As concentration times the number of years living at current house. It is important to keep in mind that this study investigated the health consequences of long-term exposure to low concentrations of As (i.e., below the acceptable levels).
Objective 1: To develop and describe a novel environmental public health indicator (EPHI), the cumulative environmental exposure index for arsenic (CEEI-As).
Objective 2: To validate the CEEI-As as an environmental indicator of health burden.
Objective 3: To evaluate the impact of the CEEI-As on the known health disparities between Mexican American and non-Hispanic whites.
Summary/Accomplishments (Outputs/Outcomes):
Groundwater As levels were assayed on 200 and GIS-based As calculated for 511 participants (n = 298 non-Hispanic; n = 213 Hispanic) and the CEEI-As generated. In the midst of the grant, the PI (and laboratory) moved to the University of North Texas Health Science Center (UNTHSC). At UNTHSC, the PI created the Health & Aging Brain/Health & Aging Brain among Latino Elders (HABLE) study. The HABLE study focuses on factors related to aging health among Mexican American adults and elders. An additional 500 participants were enrolled for analysis and validation of the CEEI-As. A number of findings have resulted from the current project. To date, we have shown that current household exposure to low concentrations of As is related to poor health outcomes, including cognitive and cardiovascular health outcomes. Current As levels were related to increased risk for cardiovascular disease, which was also influenced by genetics (i.e., AS3MT polymorphism). We found that higher blood pressure was related to higher As concentrations and that cholesterol problems (i.e., dyslipidemia) were related to As genetics (i.e., AS3MT polymorphism). We have shown that higher (but still low-concentrations) current As concentrations were related to poorer cognition; however, estimated chronic As exposure (CEEI-As as calculated by current GIS-based As x years at current residence) was a stronger predictor of cognitive abilities. We cross-validated those findings demonstrating that chronic As exposure (CEEI-As) is most strongly related to deficits in memory and language as compared to current As exposure among non-demented adults/elders. We also demonstrated that the As–cognition link varies by AS3MT polymorphism. By conducting GIS-based analyses in the Texas Alzheimer’s Research & Care Consortium (TARCC) cohort, we have found that GIS-based As levels impact cognition among those with pre-Alzheimer’s disease (AD; Mild Cognitive Impairment). This work supported the master’s thesis of Melissa Edwards from the Texas Tech University, Department of Psychology. We have shown that ethnicity impacts the arsenic-health condition link, including cognition. Additionally, our data show that free T4 levels are significantly impacted by CEEI-As with a stronger link among Hispanics. Additionally, we have begun looking at GIS-based estimates of selenium and vanadium and health outcomes as a result of this work. We found that the selenium levels are associated with memory abilities as well as depression and that the selenium–depression link varies by genetics. With regards to depression, we demonstrated that higher selenium levels were associated with significantly fewer symptoms of depression (total as well as specific subfactors of depression) and that the depression–selenium link was modified by GPX1 polymorphisms. This work has resulted in novel lines of environmental justice research focused on minority elders. We are continuing this line of work to further validate the CEEI-As and expand to other cumulative markers of exposure (i.e., selenium, vanadium, etc.). We are conducting the GIS-based analyses among an additional 500 participants and will therefore have data among over 900 participants from urban and rural-dwelling settings with over 600 Mexican Americans included in the cohorts. First, we are currently calculating GIS-based air quality and water quality data on a range of exposures for 500 participants and have previously conducted these analyses for water quality measures from 500 participants from an additional study. Longitudinal (n ≈ 300 currently) and select proteomic (n ≈ 500) data are also available in the urban-dwelling (primarily Mexican American) cohort. There is an environmental health focused research group within the team looking into each of these possible lines of research to better understand the impact of environmental exposures on aging health, particularly among Mexican American adults and elders. Additionally, we have begun collaborating with investigators on the impact of DDE on risk for cognitive dysfunction among Mexican Americans with pilot DDE levels currently being analyzed from 150 Mexican Americans with and without cognitive impairment (pre-AD). Therefore, we continue to conduct work on the CEEI-As and are generating efforts on CEEI-Se, CEEI-Va, CEEI-Pb and others.
Conclusions:
We completed Objective 1 by generating and describing the CEEI-As and demonstrating the link with poorer health outcomes (cardiovascular and neurological). We completed Objective 2 by cross-validating the CEEI-As in the larger rural-dwelling cohort (Project FRONTIER). Objective 3 was met by demonstrating the ethnic impact on As levels and how ethnicity and genetics impact the CEEI-As cognition link. Overall, this work has demonstrated that exposure to As through groundwater supplies at low concentrations has a detrimental impact on aging health, both cardiovascular and neurological health. The impact of As on health outcomes varies by As genetics and by ethnicity, with some factors being more strongly related to CEEI-As among Hispanics and African Americans and others more strongly among non-Hispanic whites. Therefore, environmental As exposure may be a modifiable factor to improve the health of our diverse aging population. Additionally, ongoing expansion and further validation of the work is being conducted among 900 participants across multiple cohorts.
Journal Articles on this Report : 16 Displayed | Download in RIS Format
Other project views: | All 23 publications | 16 publications in selected types | All 16 journal articles |
---|
Type | Citation | ||
---|---|---|---|
|
Edwards M, Hall J, Gong G, O’Bryant SE. Arsenic exposure, AS3MT polymorphism, and neuropsychological functioning among rural-dwelling adults and elders: a cross-sectional study. Environmental Health 2014;13(1):15. |
R834794 (Final) |
Exit Exit |
|
Edwards M, Johnson L, Mauer C, Barber RC, Hall J, O’Bryant SE. Regional specific groundwater arsenic levels and neuropsychological functioning: a cross-sectional study. International Journal of Environmental Health Research 2014;24(6):546-557. |
R834794 (Final) |
Exit |
|
Falkowski J, Atchison T, DeButte-Smith M, Weiner MF, O'Bryant S. Executive Functioning and the Metabolic Syndrome: A Project FRONTIER Study. Archives of Clinical Neuropsychology 2014;29(1):47-53. |
R834794 (Final) |
Exit Exit |
|
Gong G, Hargrave KA, Hobson V, Spallholz J, Boylan M, Lefforge D, O'Bryant SE. Low-level groundwater arsenic exposure impacts cognition: a Project FRONTIER study. Journal of Environmental Health 2011;74(2):16-23. |
R834794 (2011) R834794 (2012) R834794 (Final) |
Exit Exit |
|
Gong G, O'Bryant SE. Low-level arsenic exposure, AS3MT gene polymorphism and cardiovascular diseases in rural Texas counties. Environmental Research 2012;113:52-57. |
R834794 (2011) R834794 (2012) R834794 (Final) |
Exit Exit Exit |
|
Gong G, Mattevada S, O’Bryant SE. Comparison of the accuracy of kriging and IDW interpolations in estimating groundwater arsenic concentrations in Texas. Environmental Research 2014;130:59-69. |
R834794 (Final) |
Exit Exit |
|
Hall J, Edwards M, Barber R, Johnson L, Gong G, O'Bryant SE. Higher groundwater selenium exposure is associated with better memory:a Project FRONTIER study. Neuroscience & Medicine 2012;3(1):18-25. Neuroscience & Medicine |
R834794 (2011) R834794 (Final) |
Exit |
|
Johnson LA, Phillips JA, Mauer C, Edwards M, Balldin VH, Hall JR, Barber R, Conger TL, Ho EJ, O'Bryant SE. The impact of GPX1 on the association of groundwater selenium and depression: a Project FRONTIER study. BMC Psychiatry 2013;13:7. |
R834794 (2012) R834794 (Final) |
Exit Exit Exit |
|
Johnson LA, Hall JR, O’Bryant SE. A depressive endophenotype of mild cognitive impairment and alzheimer’s disease. PLoS ONE 2013;8(7):e68848. |
R834794 (Final) |
Exit Exit |
|
Johnson LA, Cushing B, Rohlfing G, Edwards M, Davenloo H, D'Agostino D, Hall JR, O'Bryant SE. The Hachinski Ischemic Scale and cognition: the influence of ethnicity. Age and Ageing 2014;43(3):364-369. |
R834794 (Final) |
Exit Exit |
|
Johnson LA, Gamboa A, Vintimilla R, Edwards M, Hall J, Weiser B, Yadav M, Dickensheets T, O'Bryant SE. A Depressive Endophenotype for Predicting Cognitive Decline among Mexican American Adults and Elders. Journal of Alzheimer's Disease: JAD 2016;54(1):201-206. |
R834794 (Final) |
Exit |
|
Menon CV, Jahn DR, Mauer CB, O'Bryant SE. Executive Functioning as a Mediator of the Relationship Between Premorbid Verbal Intelligence and Health Risk Behaviors in a Rural-Dwelling Cohort: A Project FRONTIER Study. Archives of Clinical Neuropsychology 2013;28(2):169-179. |
R834794 (Final) |
Exit Exit |
|
O'Bryant SE, Edwards M, Menon CV, Gong G, Barber RC. Long-term low-level arsenic exposure is associated with poorer neuropsychological functioning: a Project FRONTIER study. International Journal of Environmental Research and Public Health 2011;8(3):861-874. |
R834794 (2011) R834794 (2012) R834794 (Final) |
Exit Exit |
|
O'Bryant SE, Johnson L, Reisch J, Edwards M, Hall J, Barber R, Devous Sr MD, Royall D, Singh M. Risk factors for mild cognitive impairment among Mexican Americans. Alzheimer's & Dementia 2013;9(6):622-631.e1. |
R834794 (Final) |
Exit Exit |
|
O'Bryant SE, Johnson L, Balldin V, Edwards M, Barber R, Williams B, Devous M, Cushings B, Knebl J, Hall J. Characterization of Mexican Americans with mild cognitive impairment and Alzheimer's disease. Journal of Alzheimer's Disease: JAD 2013;33(2):373-379. |
R834794 (Final) |
Exit |
|
Torrence ND, John SE, Gavett BE, O'Bryant SE. An Empirical Comparison of Competing Factor Structures for the Repeatable Battery for the Assessment of Neuropsychological Status: A Project FRONTIER Study. Archives of Clinical Neuropsychology 2016;31(1):88-96. |
R834794 (Final) |
Exit Exit |
Supplemental Keywords:
Mexican American, Hispanic, proteomics, Alzheimer’s disease, mild cognitive impairment, cognition, memory, depression, gene-environment, elder health, aging, selenium, water, drinking water, groundwater, exposure, risk, risk assessment, effects, health effects, human health, bioavailability, metabolism, vulnerability, sensitive populations, carcinogen, population, elderly, age, race, genetic predisposition, genetic polymorphisms, sex, ethnic groups, susceptibility, cumulative effects, toxics, heavy metals, indicators, sustainable development, public policy, decision making, community-based, psychological, social science, ecology, epidemiology, genetics, modeling, monitoring, southwest, rural, urban, EPA Region 6Relevant Websites:
Institute for Aging & Alzheimer’s Disease Research (http://web.unthsc.edu/research/IAADR Exit ).
Progress 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.