Paul M Bradley
Introduction: Research Hydrologist/Ecologist with the South Atlantic Water Science Center focused on understanding environmental contaminant mixture exposures and real versus perceived effects to human and environmental health.
Paul is project lead, along with Kelly Smalling, of the Drinking-Water and Wastewater Infrastructure Integrated Science Team of the Ecosystems Mission, Environmental Health Program. His research focuses on human exposures to and potential effects of inorganic, organic, and microbial contaminant mixtures in drinking water at the point of use and on anthropogenic contaminant mixtures as ecosystem stressors.
Professional Experience
1988–present: Research Ecologist/Hydrologist, U.S. Geological Survey
Expertise:
• Contaminant mixtures
• Drinking water
• Water quality
• Environmental health
Education and Certifications
B.S., Applied Biology, Georgia Institute of Technology, Atlanta, Georgia
M.S., Applied Biology, Georgia Institute of Technology, Atlanta, Georgia
Ph.D., Physiological Ecology, University of South Carolina, Columbia, South Carolina
Science and Products
Study Highlights the Complexity of Chemical Mixtures in United States Streams
Environmental Fate and Transport of Contaminants of Emerging Concern (CEC), South Carolina
Recovery of Stream and Adjacent Groundwater After Wastewater Treatment Facility Closure
U.S. Geological Survey Scientists Complete First Systematic Regional Survey of Algal Toxins in Streams of the Southeastern United States
Assessing Environmental Chemical Mixtures in United States Streams
Contaminant Transport Models Aid in Understanding Trends of Chlorinated Ethenes in Public Supply Wells
Endocrine Disrupting Chemicals Persist Downstream from the Source
Chemicals Found in Treated Wastewater are Transported from Streams to Groundwater
Hormones Degrade in the Environment!
Inorganic Concentration Results for Assessment of Mixed Organic/Inorganic Chemical and Biological Exposures in North Dakota and South Dakota Tapwater, 2019
Concentrations of organic and inorganic constituents in tapwater samples from California in 2020-21 (ver. 3.1, March 2024)
Target-Chemical Concentration Results of Mixed-Organic/Inorganic Chemical Exposures in Puerto Rico Tapwater, 2017 to 2018
Pesticide and Pharmaceutical Exposure Data for Select Streams within Great Smoky Mountains National Park, 2019
Microbial Source Tracking Marker Concentrations in Congaree National Park in 2017-2019, South Carolina, USA
Target-Chemical Concentration Results of Mixed-Organic/Inorganic Chemical Exposures in Cape Cod, Massachusetts Tapwater, 2018
Concentrations of Pesticide, Pharmaceutical, and Organic Wastewater Contaminants from a Multi-Regional Assessment of Wadeable USA Streams, 2014-17
Pesticide and transformation product concentrations and risk quotients in U.S. headwater streams
Cyanotoxin Concentration and Phytoplankton Community Composition Data for Surface Water Samples Collected at Lake Mattamuskeet National Wildlife Refuge, North Carolina during summer 2015
Water-, Sediment-, and Biological-Quality Data for Waters Receiving Runoff from Five Bridges in South Carolina, 2013 to 2018
Target-Chemical Concentrations in Landfill Leachate and Wastewater Treatment Influent and Effluent
Concentrations of Pharmaceutical Contaminants and Their Predicted Effects from a Multi-Regional Assessment of Wadeable USA Streams, 2014-2017
Rapid implementation of high-frequency wastewater surveillance of SARS-CoV-2
Ecological consequences of neonicotinoid mixtures in streams
Arsenic in private well water and birth outcomes in the United States
Temporal variability in TiO2 engineered particle concentrations in rural Edisto River
Food, beverage, and feedstock processing facility wastewater: A unique and underappreciated source of contaminants to U.S. streams
Integrated science for the study of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the environment—A strategic science vision for the U.S. Geological Survey
Assessing the ecological functionality and integrity of natural ponds, excavated ponds and stormwater basins for conserving amphibian diversity
Multiple in-stream stressors degrade biological assemblages in five U.S. regions
Is there an urban pesticide signature? Urban streams in five U.S. regions share common dissolved-phase pesticides but differ in predicted aquatic toxicity
Untargeted lipidomics for determining cellular and sub-cellular responses in Zebrafish (Danio rerio) liver cells following exposure to complex mixtures in U.S. streams
Pilot-scale expanded assessment of inorganic and organic tapwater exposures and predicted effects in Puerto Rico, USA
Reconnaissance of cumulative risk of pesticides and pharmaceuticals in Great Smoky Mountains National Park streams
Science and Products
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Filter Total Items: 21
Study Highlights the Complexity of Chemical Mixtures in United States Streams
A new study highlights the complexity of chemical mixtures in streams and advances the understanding of wildlife and human exposure to complex chemical mixtures.Environmental Fate and Transport of Contaminants of Emerging Concern (CEC), South Carolina
The contaminants of emerging concern (CEC) umbrella covers several broad classes of contaminants that include: pharmaceuticals and personal care products, organic wastewater compounds, antimicrobials, antibiotics, animal and human hormones, as well as domestic and industrial detergents. The potential impacts of CECs on the environment, in general, and on natural surface-water and riparian...Recovery of Stream and Adjacent Groundwater After Wastewater Treatment Facility Closure
The hydrology and chemistry of a wastewater-impacted stream and adjacent groundwater responded rapidly (had fewer chemicals at lower concentrations) following wastewater treatment facility shutdown. However, the adjacent shallow groundwater remained a continuing source of some wastewater-derived contaminants to the stream at least 1 year post-shutdown.U.S. Geological Survey Scientists Complete First Systematic Regional Survey of Algal Toxins in Streams of the Southeastern United States
U.S. Geological Survey (USGS) scientists detected microcystin—an algal toxin—in 39 percent of 75 streams assessed in the southeastern United States. These results will inform and become part of a larger, systematic national survey of algal toxins in small streams of the United States.Assessing Environmental Chemical Mixtures in United States Streams
The U.S. Geological Survey (USGS) and the U.S. Environmental Protection Agency (EPA) are collaborating on a field-based study of chemical mixture composition and environmental effects in stream waters affected by a wide range of human activities and contaminant sources.Contaminant Transport Models Aid in Understanding Trends of Chlorinated Ethenes in Public Supply Wells
U.S. Geological Survey (USGS) scientists used a mass–balance solute–transport model to enhance an understanding of factors affecting chlorinated ethene (CE) concentrations in a public supply well. They found that long–term simulated and measured CEconcentrations were affected by dense nonaqueous phase liquid (DNAPL) volume, composition, and by the bioavailability of organic carbon that drives...Endocrine Disrupting Chemicals Persist Downstream from the Source
Endocrine disrupting chemicals (EDCs) were transported 2 kilometers downstream of a wastewater treatment plant (WWTP) outfall in a coastal plain stream. EDCs persisted downstream of the outfall with little change in the numbers of EDCs and limited decreases in EDC concentrations.Chemicals Found in Treated Wastewater are Transported from Streams to Groundwater
U.S. Geological Survey (USGS) scientists studying a midwestern stream conclude that pharmaceuticals and other contaminants in treated wastewater effluent discharged to the stream are transported into adjacent shallow groundwater. Other mobile chemicals found in wastewater are expected to have similar fates.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... - Data
Filter Total Items: 44
Inorganic Concentration Results for Assessment of Mixed Organic/Inorganic Chemical and Biological Exposures in North Dakota and South Dakota Tapwater, 2019
This data set reports results for inorganic constituents analyzed at the Redox Chemistry Laboratory in Boulder, Colorado, for the 2019 tapwater study conducted in North Dakota and South Dakota, USA. This project is part of the U.S. Geological Survey, Ecosystems Mission Area, Environmental Health Water and Wastewater Infrastructure Program.Concentrations of organic and inorganic constituents in tapwater samples from California in 2020-21 (ver. 3.1, March 2024)
This dataset contains the trace elements, cations, anions, disinfection by-products, per- and polyfluoroalkyl substances (PFAS), pharmaceutical and pesticide concentration results for the tapwater study conducted in California, November, 2020 through May, 2021. Trace elements, cations and anions were analyzed at the U.S. Geological Survey Redox Chemistry Laboratory in Boulder, Colorado. The disinfTarget-Chemical Concentration Results of Mixed-Organic/Inorganic Chemical Exposures in Puerto Rico Tapwater, 2017 to 2018
This dataset provides the water-quality results for organic and inorganic concentrations analyzed from samples collected at domestic and commercial tapwater faucets and one spring, sourced in Puerto Rico. Samples were collected in October, 2017 and August and December, 2018 from 19 locations. Samples were analyzed at various U.S. Geological Survey laboratories: the National Water Quality LaboratorPesticide and Pharmaceutical Exposure Data for Select Streams within Great Smoky Mountains National Park, 2019
This dataset included the concentration results (in nanograms per liter) for 328 pharmaceutical and pesticide compounds analyzed within the Great Smoky Mountain National Park, Tennessee and North Carolina, in 2019. Two samples were collected (July and September) at 15 locations within the park, and one location at the park boundary. Samples were analyzed at the National Water Quality Laboratory (NMicrobial Source Tracking Marker Concentrations in Congaree National Park in 2017-2019, South Carolina, USA
The dataset contains quantitative polymerase chain reaction data for microbial source tracking markers screened on water samples collected from streams and rivers within and bounding Congaree National Park from samples collected throughout the year from December 2017 through June 2019. The number of samples collected per event ranged from 4-16 over the span of 11 sample events.Target-Chemical Concentration Results of Mixed-Organic/Inorganic Chemical Exposures in Cape Cod, Massachusetts Tapwater, 2018
This dataset provides the water-quality results for organic and inorganic concentrations analyzed from samples collected at residential tapwater faucets, sourced from private drinking water wells in Cape Cod, Massachusetts. Samples were collected in July and August, 2018 from 20 locations. Samples were analyzed at various U.S. Geological Survey laboratories: the National Water Quality Laboratory iConcentrations of Pesticide, Pharmaceutical, and Organic Wastewater Contaminants from a Multi-Regional Assessment of Wadeable USA Streams, 2014-17
Human-use pharmaceutical, pesticide, and wastewater indicator compounds were analyzed at the U.S. Geological Survey, National Water Quality Laboratory, Denver, Colorado, in wadeable streams in 4 Regional Stream Quality Assessments: Northeast (NESQA), Southeast (SESQA), Pacific Northwest (PNSQA) and California (CSQA). Multiple (with few exceptions) samplings occurred at each site, during base flow,Pesticide and transformation product concentrations and risk quotients in U.S. headwater streams
This dataset includes a subset of previously released pesticide data (Morace and others, 2020) from the U.S. Geological Survey (USGS) National Water Quality Assessment Program (NAWQA) Regional Stream Quality Assessment (RSQA) project and the corresponding hazard index results calculated using the R package toxEval, which are relevant to Mahler and others, 2020. Pesticide and transformation productCyanotoxin Concentration and Phytoplankton Community Composition Data for Surface Water Samples Collected at Lake Mattamuskeet National Wildlife Refuge, North Carolina during summer 2015
Data release including concentrations of cyanotoxins and phytoplankton community composition data for water samples collected from the Lake Mattamuskeet National Wildlife Refuge in North Carolina during 2015.Water-, Sediment-, and Biological-Quality Data for Waters Receiving Runoff from Five Bridges in South Carolina, 2013 to 2018
This dataset contains water-, sediment-, and biological-quality data collected immediately upstream and downstream from 5 bridges in 3 physiographic provinces (Piedmont, Upper Coastal Plain, and Lower Coast Plain) in South Carolina during periods of observable bridge-deck runoff during 2013 to 2018. The associated report (Journey and others, 2020, "Effects of Stormwater Runoff from Selected BridgeTarget-Chemical Concentrations in Landfill Leachate and Wastewater Treatment Influent and Effluent
Concentration results and quality assurance for pharmaceutical, hormone, and per- and polyfluorinated alkyl substances (PFAS) analyzed in landfill leachate and wastewater influent and effluent. Samples were collected between July and October 2016, using U.S. Geological Survey field methods. Water-quality samples for pharmaceutical and hormone compounds (reported in nanograms per liter; ng/L) wereConcentrations of Pharmaceutical Contaminants and Their Predicted Effects from a Multi-Regional Assessment of Wadeable USA Streams, 2014-2017
Human-use pharmaceutical compounds were analyzed at the U.S. Geological Survey, National Water Quality Laboratory, Denver, Colorado, in wadeable streams in 4 Regional Stream Quality Assessments: Northeast (NESQA), Southeast (SESQA), Pacific Northwest (PNSQA) and California (CSQA). Multiple (with few exceptions) samplings occurred at each site, during base flow, between 2014 and 2017. Sites were lo - Multimedia
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Rapid implementation of high-frequency wastewater surveillance of SARS-CoV-2
There have been over 507 million cases of COVID-19, the disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), resulting in 6 million deaths globally. Wastewater surveillance has emerged as a valuable tool in understanding SARS-CoV-2 burden in communities. The National Wastewater Surveillance System (NWSS) partnered with the United States Geological Survey (USGS) to imAuthorsMeghan M. Holst, John Person, Wiley Jennings, Rory M. Welsh, Michael J. Focazio, Paul M. Bradley, W. Bane Schill, Amy E. Kirby, Zachary A. MarshEcological consequences of neonicotinoid mixtures in streams
Neonicotinoid mixtures are common in streams worldwide, but corresponding ecological responses are poorly understood. We combined experimental and observational studies to narrow this knowledge gap. The mesocosm experiment determined that concentrations of the neonicotinoids imidacloprid and clothianidin (range of exposures, 0 to 11.9 μg/liter) above the hazard concentration for 5% of species (0.0AuthorsTravis S. Schmidt, Janet L. Miller, Barbara Mahler, Peter C. Van Metre, Lisa H. Nowell, Mark W. Sandstrom, Daren Carlisle, Patrick W. Moran, Paul M. BradleyArsenic in private well water and birth outcomes in the United States
BackgroundPrenatal exposure to drinking water with arsenic concentrations >50 μg/L is associated with adverse birth outcomes, with inconclusive evidence for concentrations ≤50 μg/L. In a collaborative effort by public health experts, hydrologists, and geologists, we used published machine learning model estimates to characterize arsenic concentrations in private wells—federally unregulated for driAuthorsCatherine Bulka, Molly Scannell Bryan, Melissa Lombard, Scott Bartell, Daniel Jones, Paul M. Bradley, Veronica Vieira, Debra Silverman, Michael J. Focazio, Patricia Toccalino, Johnni Daniel, Lorraine C. Backer, Joseph D. Ayotte, Matthew O. Gribble, Maria ArgosTemporal variability in TiO2 engineered particle concentrations in rural Edisto River
Titanium dioxide (TiO2) is widely used in engineered particles including engineered nanomaterial (ENM) and pigments, yet its occurrence, concentrations, temporal variability, and fate in natural environmental systems are poorly understood. For three years, we monitored TiO2 concentrations in a rural river basin (Edisto River, < 1% urban land cover) in South Carolina, United States. The total conceAuthorsMd Mahmudun Nabi, J. Wang, Celeste A. Journey, Paul M. Bradley, Mohammed BaaloushaFood, beverage, and feedstock processing facility wastewater: A unique and underappreciated source of contaminants to U.S. streams
Process wastewaters from food, beverage, and feedstock facilities, although regulated, are an under-investigated environmental contaminant source. Food process wastewaters (FPWWs) from 23 facilities in 17 U.S. states were sampled and documented for a plethora of chemical and microbial contaminants. Of the 576 analyzed organics, 184 (32%) were detected at least once, with concentrations as large asAuthorsLaura E. Hubbard, Dana W. Kolpin, Carrie E Givens, Bradley D. Blackwell, Paul M. Bradley, James L. Gray, Rachael F. Lane, Jason R. Masoner, R. Blaine McCleskey, Kristin M. Romanok, Mark W. Sandstrom, Kelly L. Smalling, Daniel L. VilleneuveByEcosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Central Midwest Water Science Center, Kansas Water Science Center, New Jersey Water Science Center, Pennsylvania Water Science Center, South Atlantic Water Science Center (SAWSC), Upper Midwest Water Science Center, National Water Quality LaboratoryIntegrated science for the study of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the environment—A strategic science vision for the U.S. Geological Survey
Concerns related to perfluoroalkyl and polyfluoroalkyl substances (PFAS) in sources of drinking water and in natural and engineered environments have captured national attention over the last few decades. This report provides an overview of the science gaps that exist in the fields of study related to PFAS that are relevant to the U.S. Geological Survey mission and identifies opportunities where tAuthorsAndrea K. Tokranov, Paul M. Bradley, Michael J. Focazio, Douglas B. Kent, Denis R. LeBlanc, Jeff W. McCoy, Kelly L. Smalling, Jeffery A. Steevens, Patricia L. ToccalinoAssessing the ecological functionality and integrity of natural ponds, excavated ponds and stormwater basins for conserving amphibian diversity
Wetlands provide ecological functionality by maintaining and promoting regional biodiversity supporting quality habitat for aquatic organisms. Globally, habitat loss, fragmentation and degradation due to increases in agricultural activities and urban development have reduced or altered geographically isolated wetlands, thus reducing biodiversity. The objective of this study was to assess the relatAuthorsKelly L. Smalling, Sara E. Breitmeyer, John F. Bunnell, Kim J Laidig, Patrick Burritt, Marilyn Sobel, Jonathan Cohl, Michelle Hladik, Kristin M. Romanok, Paul M. BradleyMultiple in-stream stressors degrade biological assemblages in five U.S. regions
Biological assemblages in streams are affected by a wide variety of physical and chemical stressors associated with land-use development, yet the importance of combinations of different types of stressors is not well known. From 2013 to 2017, the U.S. Geological Survey completed multi-stressor/multi-assemblage stream ecological assessments in five regions of the United States (434 streams total).AuthorsIan R. Waite, Peter C. Van Metre, Patrick W. Moran, Christopher P. Konrad, Lisa H. Nowell, Michael R. Meador, Mark D. Munn, Travis S. Schmidt, Allen C. Gellis, Daren Carlisle, Paul M. Bradley, Barbara MahlerByEcosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Kansas Water Science Center, Oklahoma-Texas Water Science Center, Oregon Water Science Center, South Atlantic Water Science Center (SAWSC), Washington Water Science Center, Wyoming-Montana Water Science CenterIs there an urban pesticide signature? Urban streams in five U.S. regions share common dissolved-phase pesticides but differ in predicted aquatic toxicity
Pesticides occur in urban streams globally, but the relation of occurrence to urbanization can be obscured by regional differences. In studies of five regions of the United States, we investigated the effect of region and urbanization on the occurrence and potential toxicity of dissolved pesticide mixtures. We analyzed 225 pesticide compounds in weekly discrete water samples collected during 6–12AuthorsLisa H. Nowell, Patrick W. Moran, Laura M. Bexfield, Barbara Mahler, Peter C. Van Metre, Paul M. Bradley, Travis S. Schmidt, Daniel T. Button, Sharon L. QiByEcosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Fort Collins Science Center, Maryland-Delaware-D.C. Water Science Center, New Mexico Water Science Center, Oklahoma-Texas Water Science Center, Oregon Water Science Center, Pennsylvania Water Science Center, South Atlantic Water Science Center (SAWSC), Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center, Washington Water Science CenterUntargeted lipidomics for determining cellular and sub-cellular responses in Zebrafish (Danio rerio) liver cells following exposure to complex mixtures in U.S. streams
Surface waters often contain a variety of chemical contaminants potentially capable of producing adverse outcomes in both humans and wildlife due to impacts from industrial, urban, and agricultural activity. Here, we report the results of a zebrafish liver (ZFL) cell-based lipidomics approach to assess the potential ecotoxicological effects of complex contaminant mixtures using water collected froAuthorsHuajun Zhen, Quincy Teng, Jonathan D Mosley, Timothy W. Collette, Yang Yue, Paul M. Bradley, Drew R. EkmanPilot-scale expanded assessment of inorganic and organic tapwater exposures and predicted effects in Puerto Rico, USA
A pilot-scale expanded target assessment of mixtures of inorganic and organic contaminants in point-of-consumption drinking water (tapwater, TW) was conducted in Puerto Rico (PR) to continue to inform TW exposures and corresponding estimations of cumulative human-health risks across the US. In August 2018, a spatial synoptic pilot assessment of than 524 organic, 37 inorganic, and select microbioloAuthorsPaul M. Bradley, Ingrid Y. Padilla, Kristin M. Romanok, Kelly Smalling, Michael J. Focazio, Sara E. Breitmeyer, Mary C. Cardon, Justin M. Conley, Nicola Evans, Carrie E Givens, James L. Gray, L. Earl Gray, Phillip C. Hartig, Michelle Hladik, Christopher P. Higgins, Luke R. Iwanowicz, Rachael F. Lane, Keith Loftin, R. Blaine McCleskey, Carrie A. McDonough, Elizabeth Medlock-Kakaley, Shannon M. Meppelink, Christopher P. Weis, Vickie S. WilsonReconnaissance of cumulative risk of pesticides and pharmaceuticals in Great Smoky Mountains National Park streams
The United States (US) National Park Service (NPS) manages protected public lands to preserve biodiversity. Exposure to and effects of bioactive organic contaminants in NPS streams are challenges for resource managers. Recent assessment of pesticides and pharmaceuticals in protected-streams within the urbanized NPS Southeast Region (SER) indicated the importance of fluvial inflows from external soAuthorsPaul M. Bradley, Matt A. Kulp, Bradley J. Huffman, Kristin M. Romanok, Kelly L. Smalling, Sara E. Breitmeyer, Jimmy Clark, Celeste A. Journey - Web Tools
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