Social Impact Assessment of Human Exposure to Mercury Related to Land Use and Physicochemical Settings in the Alabama-Mobile River System

EPA Grant Number: R827168
Title: Social Impact Assessment of Human Exposure to Mercury Related to Land Use and Physicochemical Settings in the Alabama-Mobile River System
Investigators: Bonzongo, Jean-Claude J. , Bryan, Hobson C. , Chaubey, Indrajeet , Lyons, W. Berry , Roden, Eric E. , Ward, Milton G.
Current Investigators: Bonzongo, Jean-Claude J. , Bryan, Hobson C. , Chaubey, Indrajeet , Lyons, W. Berry , Roden, Eric E. , Ward, Milton G. , Warner, Kimberly A.
Institution: University of Alabama at Birmingham , Austin College
Current Institution: University of Alabama at Birmingham , The Ohio State University , University of Arkansas - Little Rock , University of Florida
EPA Project Officer: Hiscock, Michael
Project Period: December 21, 1998 through December 20, 2001
Project Amount: $804,534
RFA: Water and Watersheds (1998) RFA Text |  Recipients Lists
Research Category: Water , Water and Watersheds

Description:

Mercury (Hg) concentrations above levels that could pose a health risk have been measured recently in predatory fish from many rivers and reservoirs in the southeastern region of the United States. This sector of country is particularly vulnerable to Hg contamination in aquatic food chains due to the coexistence of natural and human-imposed conditions hypothesized to enhance the transformation of inorganic Hg to methyl-Hg, its most toxic and readily bioavailable form.

This research has two primary thrusts: (1) to explore geochemical and biological aspects of Hg cycling and contamination in selected watersheds in the Mobile- Alabama River System (MARS); and (2) to lay the groundwork for remedial policies through a social science-based process of social impact assessment and public involvement. Specific objectives are to: (i) improve our understanding of Hg biogeochemistry and its accumulation in biota within the MARS; (ii) use this information to help predict the potential for Hg bioaccumulation in areas with similar geochemical and geographical features; (iii) inform and involve key stakeholder groups regarding the science of Hg contamination and its human implications; and (iv) lay the groundwork for public understanding and support of possible remedial measures.

Approach:

We will examine the biogeochemistry of Hg in different types of aquatic environments within the MARS, which we hypothesize will have contrasting levels of methyl-Hg in water and biota based on the following arguments. First, land use and human modifications of the hydrology of rivers by the construction of dams have resulted in increased nutrient loading into streams/rivers and increased sedimentation rates near water impoundments, respectively, allowing the accumulation of organic rich particles and the development of anoxic conditions favorable to transformation of inorganic Hg to methyl-Hg. Second, the abundance of shallow-water wetlands in catchments of many river/reservoir systems in the MARS may be a significant source of methyl- Hg to parallel and downstream aquatic systems. Therefore, inorganic Hg introduced to the MARS from both point sources and discrete atmospheric deposition would easily build up in aquatic food chains, particularly in dammed locations receiving industrial, agriculture or municipal runoff and/or water inputs from surrounding wetlands. Finally, since the findings of this study may result in appropriate regulatory responses, our plan includes the involvement of the public in the assessment of risk imposed by elevated Hg levels in fish and the design of policy recommendations for remedial measures.

Expected Results:

This research project is expected: (1) to provide an assessment of Hg biogeochemistry with an overall goal of achieving an improved understanding of the impact of land use, dams and natural settings such as wetlands on Hg cycling; and (2) to discern the policy implications of these findings to achieve effective remedial strategies. The results of our research/spatial analysis in the MARS will have direct transferability to other areas with similar geochemical and geographical features, and will help predict the potential for Hg bioaccumulation in aquatic biota (e.g., other areas within the state and in neighboring states in the Southeast).

Publications and Presentations:

Publications have been submitted on this project: View all 26 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 4 journal articles for this project

Supplemental Keywords:

Mercury, Alabama, coastal plain, cycling, GIS, environmental policy., RFA, Scientific Discipline, Water, Geographic Area, Water & Watershed, Ecology, Hydrology, Environmental Chemistry, State, Chemistry, Wet Weather Flows, Ecological Risk Assessment, Agronomy, Biology, Watersheds, Mercury, aquatic, anthropogenic stress, aquatic ecosystem, fate and transport, food chain, agricultural discharges, watershed, social impact assessment, runoff, urban runoff, Alabama (AL), mercury cycling, soils, aquatic degradation, citizen perceptions, biogeochemical cycling, methylation, methylmercury, watershed influences, marine environment, GIS, water quality, public policy, mercury content, land management, bioaccumulation

Progress and Final Reports:

  • 1999 Progress Report
  • 2000
  • Final Report