Dr. Larry Barber is a Research Geologist with the USGS Water Resources Mission Area and Integrated Water Chemistry Assessment Laboratory.
I joined the USGS NRP as a student appointments in 1982. Since then, my research has involved long-term interdisciplinary research projects that characterize environmental sources of organic and inorganic contaminants, quantify the biogeochemical processes that control their fate, and assess their potential effects on aquatic ecosystems and human health. Particular emphasis is focused on the interactions between chemistry, hydrology, and biology. A major area of expertise is the analysis of emerging contaminants by gas chromatography/tandem mass spectrometry, which provides a foundation for assessing their occurrence, exposure pathways, and impacts.
Current research focuses on biologically-active contaminants and receiving water (surface water and groundwater) attenuation capacity. Compounds being investigated include endocrine disrupting chemicals, neuro-active pharmaceuticals, and antimicrobials. We develop state-of-the-science approaches to landscape-based, watershed-scale (second-order streams to continental rivers) evaluation of chemical loading and fate combined with the field-based biological assays, to establish a holistic understanding of contaminant behavior and impacts. This interdisciplinary research involves teams of scientists to allow comprehensive evaluation of critical water resource issues.
Science and Products
Unique Approach to Measure Per- and Polyfluoroalkyl Substances Uptake in Fish, Mussels, and Passive Samplers
Per- and polyfluoroalkyl substances (PFAS) uptake and bioconcentration by fish and mussels ─ housed in mobile laboratories at a legacy fire-training area contaminated by aqueous film-forming foams ─ varied by species, sex, and compound. PFAS in passive samplers deployed at the same time mimicked uptake by fish but not mussels indicating that passive samplers might prove useful as screening tools...
Integrated Assessments of Potential Risks to Aquatic Organisms and Public Water Supply from Wastewater-Derived Chemical Mixtures in the Chesapeake Bay Watershed
Proper management of contaminants of emerging concern in the Chesapeake Bay region requires scientific efforts to understand the risk posed to aquatic resources from the “cocktail” of multiple contaminants that is often present. This research aims to assess the occurrence, sources, environmental impacts, biological effects, and the human health impacts of toxic contaminants in rivers.
Bioactive Chemical Research
About the ResearchBioactive Chemicals Research as part of the Environmental Health Program applies a collaborative transdisciplinary approach to conduct research to minimize the risk to human and aquatic organism health from exposure to contaminants in water resources. the research integrates analytical chemistry, modeling, laboratory-, and field-based experiments to identify and quantify key...
Refined Model Provides a Screening Tool to Understand Exposure to Contaminants from Incidental Wastewater Reuse
Refinement of the existing national-scale “de facto reuse incidence in our nation’s consumable supply” (DRINCS) model, complemented by field measurements, provides a screening tool to understand human and wildlife exposure to toxicants and pathogens associated with the incidental reuse of treated wastewater in the Shenandoah River watershed. The model results can be accessed in a companion web...
GIS-based landscape analysis to identify sources of endocrine disrupting chemicals
A key component to assessing the contaminant exposure pathways in streams and rivers of the Chesapeake Bay is using GIS-based landscape analysis to identify sources of endocrine disrupting chemicals. Municipal and industrial wastewater treatment plant (WWTP) discharges are potentially major sources of EDCs to streams, and therefore understanding the de facto wastewater reuse (represented as...
Per- and Polyfluoroalkyl Substances From Firefighting and Domestic Wastewater Remain in Groundwater for Decades
New study explores the persistence and transport of poly- and perfluoroalkyl substances (PFASs) that originated from both firefighting and domestic wastewater sources. Although the fire training area and wastewater facility were decommissioned over 20 years ago, both sites continue to be sources of PFASs to groundwater.
Long-Term Study Finds Endocrine Disrupting Chemicals in Urban Waterways
U.S. Geological Survey (USGS) scientists determined that endocrine disrupting chemicals (EDCs) were present in wastewater treatment plant (WWTP) effluent, water, and fish tissue in urban waterways in the Great Lakes and upper Mississippi River Regions (Indiana, Illinois, Michigan, Minnesota, and Ohio) during 1999 through 2009.
Neuroactive Pharmaceuticals in Minnesota Rivers
A team of scientists from the U.S. Geological Survey (USGS) and the University of Colorado measured seven neuroactive pharmaceutical compounds in treated wastewater and downstream receiving waters at 24 sites across Minnesota. The analysis of samples collected upstream and downstream of wastewater treatment plants indicated that wastewater treatment plants were the major source of these chemicals.
Hormones Degrade in the Environment!
In two separate studies, U.S. Geological Survey (USGS) scientists demonstrated that hormones such as estrogen can biodegrade in stream and groundwater environments. This is an important finding because the science, regulatory, and environmental communities have concerns about the environmental fate of endocrine-disrupting chemicals, such as hormones, in the human wastewaters discharged to the...
Science and Products
- Science
Unique Approach to Measure Per- and Polyfluoroalkyl Substances Uptake in Fish, Mussels, and Passive Samplers
Per- and polyfluoroalkyl substances (PFAS) uptake and bioconcentration by fish and mussels ─ housed in mobile laboratories at a legacy fire-training area contaminated by aqueous film-forming foams ─ varied by species, sex, and compound. PFAS in passive samplers deployed at the same time mimicked uptake by fish but not mussels indicating that passive samplers might prove useful as screening tools...Integrated Assessments of Potential Risks to Aquatic Organisms and Public Water Supply from Wastewater-Derived Chemical Mixtures in the Chesapeake Bay Watershed
Proper management of contaminants of emerging concern in the Chesapeake Bay region requires scientific efforts to understand the risk posed to aquatic resources from the “cocktail” of multiple contaminants that is often present. This research aims to assess the occurrence, sources, environmental impacts, biological effects, and the human health impacts of toxic contaminants in rivers.Bioactive Chemical Research
About the ResearchBioactive Chemicals Research as part of the Environmental Health Program applies a collaborative transdisciplinary approach to conduct research to minimize the risk to human and aquatic organism health from exposure to contaminants in water resources. the research integrates analytical chemistry, modeling, laboratory-, and field-based experiments to identify and quantify key...Refined Model Provides a Screening Tool to Understand Exposure to Contaminants from Incidental Wastewater Reuse
Refinement of the existing national-scale “de facto reuse incidence in our nation’s consumable supply” (DRINCS) model, complemented by field measurements, provides a screening tool to understand human and wildlife exposure to toxicants and pathogens associated with the incidental reuse of treated wastewater in the Shenandoah River watershed. The model results can be accessed in a companion web...GIS-based landscape analysis to identify sources of endocrine disrupting chemicals
A key component to assessing the contaminant exposure pathways in streams and rivers of the Chesapeake Bay is using GIS-based landscape analysis to identify sources of endocrine disrupting chemicals. Municipal and industrial wastewater treatment plant (WWTP) discharges are potentially major sources of EDCs to streams, and therefore understanding the de facto wastewater reuse (represented as...Per- and Polyfluoroalkyl Substances From Firefighting and Domestic Wastewater Remain in Groundwater for Decades
New study explores the persistence and transport of poly- and perfluoroalkyl substances (PFASs) that originated from both firefighting and domestic wastewater sources. Although the fire training area and wastewater facility were decommissioned over 20 years ago, both sites continue to be sources of PFASs to groundwater.Long-Term Study Finds Endocrine Disrupting Chemicals in Urban Waterways
U.S. Geological Survey (USGS) scientists determined that endocrine disrupting chemicals (EDCs) were present in wastewater treatment plant (WWTP) effluent, water, and fish tissue in urban waterways in the Great Lakes and upper Mississippi River Regions (Indiana, Illinois, Michigan, Minnesota, and Ohio) during 1999 through 2009.Neuroactive Pharmaceuticals in Minnesota Rivers
A team of scientists from the U.S. Geological Survey (USGS) and the University of Colorado measured seven neuroactive pharmaceutical compounds in treated wastewater and downstream receiving waters at 24 sites across Minnesota. The analysis of samples collected upstream and downstream of wastewater treatment plants indicated that wastewater treatment plants were the major source of these chemicals.Hormones Degrade in the Environment!
In two separate studies, U.S. Geological Survey (USGS) scientists demonstrated that hormones such as estrogen can biodegrade in stream and groundwater environments. This is an important finding because the science, regulatory, and environmental communities have concerns about the environmental fate of endocrine-disrupting chemicals, such as hormones, in the human wastewaters discharged to the... - Publications
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