ARRA Investments in Preventing Exposure to Toxic Pollutants
Public Health Burden
Many of America’s lakes, rivers, streams, and groundwater sources are contaminated with toxic industrial pollutants. Some of these pollutants, such as mercury and polychlorinated biphenyls (PCBs), are becoming concentrated in the food chain, so that fish consumption may cause exposure to unsafe levels of toxicants. Others, such as tretrachloroethylene (PCE), lead to direct exposure through drinking contaminated water or breathing vapors released from contaminated sites. Although the exact incidence of these types of exposures is difficult to quantify, these exposures are linked to cancer, heart disease, reproductive and developmental abnormalities, and numerous other diseases and dysfunctions. Prevention of exposures through improved exposure assessment modeling and remediation activities is the foundation of the National Institute of Environmental Health Science’s Superfund Research Program.
Assessing and Addressing Exposure to Contaminated Groundwater
Understanding contaminant behavior in the environment is critical to improve remediation processes, and to prevent and predict exposures to toxic dense non-aqueous phase liquids (DNAPLs) such as PCBs and PCE. DNAPLs are exceptionally difficult to remove from soil, sediments, and groundwater due to their unpredictable movement in the environment. ARRA grants fund research to address this important groundwater contamination issue, from developing better models for fate, transport and exposure assessment, to testing new remedies for DNAPL cleanup:
Two universities are collaborating to understand the physical forces operating on the micro pore scale level that affect the movement of DNAPLs through the subsurface. Understanding how these chemicals migrate and dissolve will aid in the removal or mitigation of these contaminants.
A community-based study will investigate the migration of PCE from soil and groundwater to the indoor air (vapor intrusion) at homes and a school located on a redeveloped industrial site. Researchers will conduct monitoring, modeling, and exposure assessment in a unique study, the first to use field data to systematically verify and improve models predicting exposure and risk.
Incomplete remediation of some pollutants can result in the formation of compounds more toxic than the original pollutant. ARRA-funded researchers are working to create a tool for complete degradation of trichloroethylene and PCBs in groundwater that uses iron nanoparticles to both reduce and oxidize these decay-resistant contaminants in groundwater.
New Methods for Sediment Clean-up
Approximately ten percent of the nation’s waterways have potentially harmful levels of contaminants in their sediments, causing thousands of fish consumption advisories nationwide. Without improved methods for sediment remediation, human health impacts will continue for generations. ARRA funding is accelerating the development of novel methods to remediate contaminated sediment sites and monitor the progress of remediation processes:
Researchers are optimizing a waterjet system to deliver chemical or biological amendments that can speed the rate of sediment remediation processes without harming the benthic communities or disturbing sediments through resuspension of contaminant in the water.
Scientists are investigating a novel approach to monitor the effectiveness of a new sediment remediation process. The system combines a unique sampling method and tracking of radio-labeled PCBs and will greatly accelerate our understanding of the fate and transport of this recalcitrant contaminant.
Researchers studying the long term fate of mercury in sediment are evaluating the use of reactive caps to stabilize the hazardous metal and prevent it from entering the water systems and the food chain.
Investigators are evaluating the potential for using applied electric currents and aeration to stimulate microbes in the soil, increasing the rate of biodegradation of PCBs.
-- Collaborative Models of DNAPL Dissolution in Porous Medium Systems -- Gandolfi, A. Jay (AZ); 5 P42 ES005948-17 -- Collaborative Models of DNAPL Dissolution in Porous Medium Systems -- Swenberg, James (NC)
-- Vapor Intrusion Exposures -- Ozonoff, David (MA); 2 P42 ES013660-05 -- Vapor Intrusion Exposures -- Boekelheide, Kim (RI)
-- Iron Nanoparticle-Based Remediation of Chloro-organics -- Hennig, Bernhard (KY); 5 P42 ES004705-22 -- Iron Nanoparticle-Based Remediation of Chloro-organics -- Smith, Martin (CA)
-- In-Situ Sediment Remediation Using Benthic Waterjet Amendment Placement -- Burken, Joel (MO)
-- Pilot-Scale Research of Novel Amendment Delivery for In-Situ Sediment Remediation -- Ghosh, Upal (MD)
-- Sequestration and Immobilization of Metal and Metalloid Contaminants in Sediments -- O’Day, Peggy (CA)
-- Integrating Microbial Biostimulation and Electrolytic Aeration to Degrade POPs -- May, Harold (SC)
Page Last Updated on June 30, 2018
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