Michelle L Hladik, PhD
(She/her)I am an environmental organic chemist whose current research focuses on the fate and transport of current-use pesticides and other organic contaminants in aquatic and terrestrial environments.
Much of my research is focused on pesticides but also includes other organic contaminants. I direct a research laboratory that is focused on developing new methods to measure pesticides and their degradates in water, sediment, and biota. My laboratory specializes in small samples sizes, complex matrices, and non-standard procedues. Additionally, I also work on developing methods and measuring disinfection by-products in treated water (especially those that are not-currently regulated and are understudied) with a focus on wastewater discharges.
Professional Experience
Research Chemist, USGS, California Water Science Center, Sacramento, 2006 to present
Chemist, USGS, California Water Science Center, Sacramento, 2005-2006
Graduate Fellow/Research and Teaching Assistant, Deparment of Geography and Environmental Engineering, Johns Hopkins University, 1999-2005
Undergraduate Research Summer Institute, Department of Chemistry, Vassar College, 1997,1998
Undergraduate Research and Teaching Assistant, Department of Chemistry, Vassar College ,1997,1998
Education and Certifications
Ph.D. 2005, Environmental Engineering and Chemistry, Johns Hopkins University, Baltimore, Maryland
B.A. 1999, Chemistry, Vassar College, Poughkeepsie, New York
Science and Products
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Exposure and potential effects of pesticides and pharmaceuticals in protected streams of the US National Park Service southeast Region
Globally protected areas offer refugia for a broad range of taxa including threatened and endangered species. The United States National Park Service (NPS) manages public lands to preserve biodiversity, but increasing park visitation and development of surrounding landscapes increase exposure to and effects from bioactive contaminants. The risk (exposure and hazard) to NPS protected...
Authors
Paul M. Bradley, Kristin M. Romanok, Jeffrey R. Duncan, William Battaglin, Jimmy Clark, Michelle Hladik, Bradley Huffman, Luke Iwanowicz, Celeste A. Journey, Kelly Smalling
By
Ecosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Colorado Water Science Center, Eastern Ecological Science Center, New Jersey Water Science Center, South Atlantic Water Science Center (SAWSC)
Pesticide mixtures in the Sacramento–San Joaquin Delta, 2016–17: Results from year 2 of the Delta Regional Monitoring Program
The Delta Regional Monitoring Program was developed by the Central Valley Regional Water Quality Control Board in response to the decline of pelagic fish species in the Sacramento–San Joaquin Delta that was observed in the early 2000s. The U.S. Geological Survey, in cooperation with the Delta Regional Monitoring Program, has been responsible for collecting and analyzing surface-water...
Authors
Matthew D. De Parsia, Emily E. Woodward, James L. Orlando, Michelle L. Hladik
Review of and recommendations for monitoring contaminants and their effects in the San Francisco Bay−Delta
Legacy and current-use contaminants enter into and accumulate throughout the San Francisco Bay−Delta (Bay−Delta), and are present at concentrations with known effects on species important to this diverse watershed. There remains major uncertainty and a lack of focused research able to address and provide understanding of effects across multiple biological scales, despite previous and...
Authors
Richard E Connon, Simone Hasenbein, Susanne M. Brander, Helen C. Poynton, Erika B Holland, Daniel Schlenk, James Orlando, Michelle Hladik, Tracy K. Collier, Nathaniel L Scholz, John P Incardona, Nancy D. Denslow, Amro Hamdoun, Sascha Nicklisch, Natalia Garcia-Reyero, Edward J. Perkins, Evan P Gallagher, Xin Deng, Dan Wang, Stephanie Fong, Richard S Breuer, Mehrdad Hajibabei, James B Brown, John K Colbourne, Thomas M Young, Gary Cherr, Andrew Whitehead, Anne E. Todgham
Effects of the neonicotinoid insecticide clothianidin on southern leopard frog (Rana sphenocephala) tadpole behavior
Neonicotinoid insecticides are highly water soluble with relatively long half-lives, which allows them to move into and persist in aquatic ecosystems. However, little is known of the impacts of neonicotinoids on non-target vertebrates, especially at sublethal concentrations. We evaluated the effects of the neonicotinoid clothianidin on the behavior of southern leopard frog tadpoles (Rana...
Authors
J. N. Holtswarth, F. E. Rowland, Holly J. Puglis, Michelle Hladik, Elisabeth B. Webb
Urban stormwater: An overlooked pathway of extensive mixed contaminants to surface and groundwaters in the United States
Increasing global reliance on stormwater control measures to reduce discharge to surface water, increase groundwater recharge, and minimize contaminant delivery to receiving waterbodies necessitates improved understanding of stormwater-contaminant profiles. A multi-agency study of organic and inorganic chemicals in urban stormwater from 50 runoff events at 21 sites across the United...
Authors
Jason R. Masoner, Dana W. Kolpin, Isabelle M. Cozzarelli, Larry B. Barber, D.S. Burden, William T. Foreman, Kenneth J. Forshay, Edward Furlong, Justin F. Groves, Michelle Hladik, Matthew E. Hopton, Jeanne B. Jaeschke, Steffanie H. Keefe, David Krabbenhoft, Richard Lowrance, Kristin Romanok, David L. Rus, William R. Selbig, Brad Williams, Paul Bradley
By
Water Resources Mission Area, Science Synthesis, Analysis and Research Program, Contaminant Biology, Science Analytics and Synthesis (SAS) Program, Toxic Substances Hydrology, California Water Science Center, Central Midwest Water Science Center, New Jersey Water Science Center, Oklahoma-Texas Water Science Center, South Atlantic Water Science Center (SAWSC), Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center, Reston Biogeochemical Processes in Groundwater Laboratory
Toxicokinetics of imidacloprid-coated wheat seeds in Japanese quail (Coturnix japonica) and an evaluation of hazard
Birds are potentially exposed to neonicotinoid insecticides by ingestion of coated seeds during crop planting. Adult male Japanese quail were orally dosed with wheat seeds coated with an imidacloprid (IMI) formulation at either 0.9 mg/kg body weight (BW) or 2.7 mg/kg BW (~3 and 9% of IMI LD50 for Japanese quail, respectively) for 1 or 10 days. Quail were euthanized between 1 and 24 h...
Authors
Thomas G. Bean, Michael S. Gross, Natalie K. Karouna-Renier, Paula F. P. Henry, Sandra L. Schultz, Michelle Hladik, Kathryn Kuivila, Barnett A. Rattner
Chlorinated byproducts of neonicotinoids and their metabolites: An unrecognized human exposure potential?
We recently reported the initial discovery of neonicotinoid pesticides in drinking water and their potential for transformation through chlorination and alkaline hydrolysis during water treatment. The objectives of this research were: (1) to determine if neonicotinoid metabolites are relevant to drinking water exposure and (2) to identify the products formed from chlorination of...
Authors
Kathryn L. Klarich Wong, Danielle T. Webb, Matthew R. Nagorzanski, Dana W. Kolpin, Michelle L. Hladik, David M. Cwiertny, Gregory H. LeFevre
Organic geochemistry and toxicology of a stream impacted by unconventional oil and gas wastewater disposal operations
Water and sediment extracts samples were analyzed for extractable hydrocarbons by gas chromatography/mass spectrometry (GC/MS) using an Agilent (Agilent Technologies, Palo Alto, CA, USA) 7890 series GC and 5975 electron ionization (EI) mass selective detector (MSD) operated in scan mode. Agilent ChemStation software was used for data acquisition and analysis (version E.02.00.493 on GC/MS...
Authors
William H. Orem, Matthew S. Varonka, Lynn M. Crosby, Karl B. Haase, Keith A. Loftin, Michelle L. Hladik, Denise M. Akob, Calin Tatu, Adam C. Mumford, Jeanne B. Jaeschke, Anne L. Bates, Tiffani Schell, Isabelle M. Cozzarelli
Reconnaissance of mixed organic and inorganic chemicals in private and public supply tapwaters at selected residential and workplace sites in the United States
Safe drinking water at the point-of-use (tapwater, TW) is a United States public health priority. Multiple lines of evidence were used to evaluate potential human health concerns of 482 organics and 19 inorganics in TW from 13 (7 public supply, 6 private well self-supply) home and 12 (public supply) workplace locations in 11 states. Only uranium (61.9 μg L–1, private well) exceeded a...
Authors
Paul M. Bradley, Dana W. Kolpin, Kristin M. Romanok, Kelly L. Smalling, Michael J. Focazio, Juliane B. Brown, Mary C. Cardon, Kurt D. Carpenter, Steven R. Corsi, Laura A. DeCicco, Julie E. Dietze, Nicola Evans, Edward T. Furlong, Carrie E. Givens, James L. Gray, Dale W. Griffin, Christopher P. Higgins, Michelle L. Hladik, Luke R. Iwanowicz, Celeste A. Journey, Kathryn Kuivila, Jason R. Masoner, Carrie A. McDonough, Michael T. Meyer, James L. Orlando, Mark J. Strynar, Christopher P. Weis, Vickie S. Wilson
By
Ecosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Central Midwest Water Science Center, Colorado Water Science Center, Eastern Ecological Science Center, Kansas Water Science Center, New Jersey Water Science Center, Oregon Water Science Center, South Atlantic Water Science Center (SAWSC), St. Petersburg Coastal and Marine Science Center, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center, National Water Quality Laboratory
Methods used for the collection and analysis of chemical and biological data for the Tapwater Exposure Study, United States, 2016–17
In 2016, the U.S. Geological Survey (USGS) Environmental Health Mission Area, initiated the Tapwater Exposure Study as part of an infrastructure project to assess human exposure to potential threats from complex mixtures of contaminants. In the pilot phase (2016), samples were collected from 11 States throughout the United States, and in the second phase (2017), the study focused on the...
Authors
Kristin M. Romanok, Dana W. Kolpin, Shannon M. Meppelink, Maria Argos, Juliane B. Brown, Michael J. Devito, Julie E. Dietze, Carrie E. Givens, James L. Gray, Christopher P. Higgins, Michelle L. Hladik, Luke R. Iwanowicz, Keith A. Loftin, R. Blaine McCleskey, Carrie A. McDonough, Michael T. Meyer, Mark J. Strynar, Christopher P. Weis, Vickie S. Wilson, Paul M. Bradley
Dissolved pesticide concentrations in the lower Sacramento River and its source waters, California, 2016
As part of a collaborative study designed to better understand water-quality conditions in the Sacramento River, surface-water samples were collected from the lower Sacramento River and five of its tributaries and then analyzed by the U.S. Geological Survey for a suite of 162 current-use pesticides and pesticide degradates. Samples were collected in May and October 2016 at 16 sites on...
Authors
Sean M. Stout, James L. Orlando, Megan McWayne-Holmes, Corey Sanders, Michelle L. Hladik
Fate and transport of nitrapyrin in agroecosystems: Occurrence in agricultural soils, subsurface drains, and receiving streams in the Midwestern US
Nitrapyrin is a nitrification inhibitor that is co-applied with nitrogen fertilizer in agroecosystems. There is limited information on the fate of nitrapyrin after it is applied to agricultural soils. Over the course of one year (March 2016 to June 2017), 192 water samples from seven streams across Iowa and Illinois were analyzed for nitrapyrin, its metabolite 6‑chloropicolinic acid (6...
Authors
Emily Woodward, Dana W. Kolpin, Wei Zheng, Nancy L Holm, Shannon M. Meppelink, Paul J. Terrio, Michelle Hladik
Science and Products
Filter Total Items: 17
Filter Total Items: 45
No Result Found
Filter Total Items: 119
Exposure and potential effects of pesticides and pharmaceuticals in protected streams of the US National Park Service southeast Region
Globally protected areas offer refugia for a broad range of taxa including threatened and endangered species. The United States National Park Service (NPS) manages public lands to preserve biodiversity, but increasing park visitation and development of surrounding landscapes increase exposure to and effects from bioactive contaminants. The risk (exposure and hazard) to NPS protected...
Authors
Paul M. Bradley, Kristin M. Romanok, Jeffrey R. Duncan, William Battaglin, Jimmy Clark, Michelle Hladik, Bradley Huffman, Luke Iwanowicz, Celeste A. Journey, Kelly Smalling
By
Ecosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Colorado Water Science Center, Eastern Ecological Science Center, New Jersey Water Science Center, South Atlantic Water Science Center (SAWSC)
Pesticide mixtures in the Sacramento–San Joaquin Delta, 2016–17: Results from year 2 of the Delta Regional Monitoring Program
The Delta Regional Monitoring Program was developed by the Central Valley Regional Water Quality Control Board in response to the decline of pelagic fish species in the Sacramento–San Joaquin Delta that was observed in the early 2000s. The U.S. Geological Survey, in cooperation with the Delta Regional Monitoring Program, has been responsible for collecting and analyzing surface-water...
Authors
Matthew D. De Parsia, Emily E. Woodward, James L. Orlando, Michelle L. Hladik
Review of and recommendations for monitoring contaminants and their effects in the San Francisco Bay−Delta
Legacy and current-use contaminants enter into and accumulate throughout the San Francisco Bay−Delta (Bay−Delta), and are present at concentrations with known effects on species important to this diverse watershed. There remains major uncertainty and a lack of focused research able to address and provide understanding of effects across multiple biological scales, despite previous and...
Authors
Richard E Connon, Simone Hasenbein, Susanne M. Brander, Helen C. Poynton, Erika B Holland, Daniel Schlenk, James Orlando, Michelle Hladik, Tracy K. Collier, Nathaniel L Scholz, John P Incardona, Nancy D. Denslow, Amro Hamdoun, Sascha Nicklisch, Natalia Garcia-Reyero, Edward J. Perkins, Evan P Gallagher, Xin Deng, Dan Wang, Stephanie Fong, Richard S Breuer, Mehrdad Hajibabei, James B Brown, John K Colbourne, Thomas M Young, Gary Cherr, Andrew Whitehead, Anne E. Todgham
Effects of the neonicotinoid insecticide clothianidin on southern leopard frog (Rana sphenocephala) tadpole behavior
Neonicotinoid insecticides are highly water soluble with relatively long half-lives, which allows them to move into and persist in aquatic ecosystems. However, little is known of the impacts of neonicotinoids on non-target vertebrates, especially at sublethal concentrations. We evaluated the effects of the neonicotinoid clothianidin on the behavior of southern leopard frog tadpoles (Rana...
Authors
J. N. Holtswarth, F. E. Rowland, Holly J. Puglis, Michelle Hladik, Elisabeth B. Webb
Urban stormwater: An overlooked pathway of extensive mixed contaminants to surface and groundwaters in the United States
Increasing global reliance on stormwater control measures to reduce discharge to surface water, increase groundwater recharge, and minimize contaminant delivery to receiving waterbodies necessitates improved understanding of stormwater-contaminant profiles. A multi-agency study of organic and inorganic chemicals in urban stormwater from 50 runoff events at 21 sites across the United...
Authors
Jason R. Masoner, Dana W. Kolpin, Isabelle M. Cozzarelli, Larry B. Barber, D.S. Burden, William T. Foreman, Kenneth J. Forshay, Edward Furlong, Justin F. Groves, Michelle Hladik, Matthew E. Hopton, Jeanne B. Jaeschke, Steffanie H. Keefe, David Krabbenhoft, Richard Lowrance, Kristin Romanok, David L. Rus, William R. Selbig, Brad Williams, Paul Bradley
By
Water Resources Mission Area, Science Synthesis, Analysis and Research Program, Contaminant Biology, Science Analytics and Synthesis (SAS) Program, Toxic Substances Hydrology, California Water Science Center, Central Midwest Water Science Center, New Jersey Water Science Center, Oklahoma-Texas Water Science Center, South Atlantic Water Science Center (SAWSC), Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center, Reston Biogeochemical Processes in Groundwater Laboratory
Toxicokinetics of imidacloprid-coated wheat seeds in Japanese quail (Coturnix japonica) and an evaluation of hazard
Birds are potentially exposed to neonicotinoid insecticides by ingestion of coated seeds during crop planting. Adult male Japanese quail were orally dosed with wheat seeds coated with an imidacloprid (IMI) formulation at either 0.9 mg/kg body weight (BW) or 2.7 mg/kg BW (~3 and 9% of IMI LD50 for Japanese quail, respectively) for 1 or 10 days. Quail were euthanized between 1 and 24 h...
Authors
Thomas G. Bean, Michael S. Gross, Natalie K. Karouna-Renier, Paula F. P. Henry, Sandra L. Schultz, Michelle Hladik, Kathryn Kuivila, Barnett A. Rattner
Chlorinated byproducts of neonicotinoids and their metabolites: An unrecognized human exposure potential?
We recently reported the initial discovery of neonicotinoid pesticides in drinking water and their potential for transformation through chlorination and alkaline hydrolysis during water treatment. The objectives of this research were: (1) to determine if neonicotinoid metabolites are relevant to drinking water exposure and (2) to identify the products formed from chlorination of...
Authors
Kathryn L. Klarich Wong, Danielle T. Webb, Matthew R. Nagorzanski, Dana W. Kolpin, Michelle L. Hladik, David M. Cwiertny, Gregory H. LeFevre
Organic geochemistry and toxicology of a stream impacted by unconventional oil and gas wastewater disposal operations
Water and sediment extracts samples were analyzed for extractable hydrocarbons by gas chromatography/mass spectrometry (GC/MS) using an Agilent (Agilent Technologies, Palo Alto, CA, USA) 7890 series GC and 5975 electron ionization (EI) mass selective detector (MSD) operated in scan mode. Agilent ChemStation software was used for data acquisition and analysis (version E.02.00.493 on GC/MS...
Authors
William H. Orem, Matthew S. Varonka, Lynn M. Crosby, Karl B. Haase, Keith A. Loftin, Michelle L. Hladik, Denise M. Akob, Calin Tatu, Adam C. Mumford, Jeanne B. Jaeschke, Anne L. Bates, Tiffani Schell, Isabelle M. Cozzarelli
Reconnaissance of mixed organic and inorganic chemicals in private and public supply tapwaters at selected residential and workplace sites in the United States
Safe drinking water at the point-of-use (tapwater, TW) is a United States public health priority. Multiple lines of evidence were used to evaluate potential human health concerns of 482 organics and 19 inorganics in TW from 13 (7 public supply, 6 private well self-supply) home and 12 (public supply) workplace locations in 11 states. Only uranium (61.9 μg L–1, private well) exceeded a...
Authors
Paul M. Bradley, Dana W. Kolpin, Kristin M. Romanok, Kelly L. Smalling, Michael J. Focazio, Juliane B. Brown, Mary C. Cardon, Kurt D. Carpenter, Steven R. Corsi, Laura A. DeCicco, Julie E. Dietze, Nicola Evans, Edward T. Furlong, Carrie E. Givens, James L. Gray, Dale W. Griffin, Christopher P. Higgins, Michelle L. Hladik, Luke R. Iwanowicz, Celeste A. Journey, Kathryn Kuivila, Jason R. Masoner, Carrie A. McDonough, Michael T. Meyer, James L. Orlando, Mark J. Strynar, Christopher P. Weis, Vickie S. Wilson
By
Ecosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Central Midwest Water Science Center, Colorado Water Science Center, Eastern Ecological Science Center, Kansas Water Science Center, New Jersey Water Science Center, Oregon Water Science Center, South Atlantic Water Science Center (SAWSC), St. Petersburg Coastal and Marine Science Center, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center, National Water Quality Laboratory
Methods used for the collection and analysis of chemical and biological data for the Tapwater Exposure Study, United States, 2016–17
In 2016, the U.S. Geological Survey (USGS) Environmental Health Mission Area, initiated the Tapwater Exposure Study as part of an infrastructure project to assess human exposure to potential threats from complex mixtures of contaminants. In the pilot phase (2016), samples were collected from 11 States throughout the United States, and in the second phase (2017), the study focused on the...
Authors
Kristin M. Romanok, Dana W. Kolpin, Shannon M. Meppelink, Maria Argos, Juliane B. Brown, Michael J. Devito, Julie E. Dietze, Carrie E. Givens, James L. Gray, Christopher P. Higgins, Michelle L. Hladik, Luke R. Iwanowicz, Keith A. Loftin, R. Blaine McCleskey, Carrie A. McDonough, Michael T. Meyer, Mark J. Strynar, Christopher P. Weis, Vickie S. Wilson, Paul M. Bradley
Dissolved pesticide concentrations in the lower Sacramento River and its source waters, California, 2016
As part of a collaborative study designed to better understand water-quality conditions in the Sacramento River, surface-water samples were collected from the lower Sacramento River and five of its tributaries and then analyzed by the U.S. Geological Survey for a suite of 162 current-use pesticides and pesticide degradates. Samples were collected in May and October 2016 at 16 sites on...
Authors
Sean M. Stout, James L. Orlando, Megan McWayne-Holmes, Corey Sanders, Michelle L. Hladik
Fate and transport of nitrapyrin in agroecosystems: Occurrence in agricultural soils, subsurface drains, and receiving streams in the Midwestern US
Nitrapyrin is a nitrification inhibitor that is co-applied with nitrogen fertilizer in agroecosystems. There is limited information on the fate of nitrapyrin after it is applied to agricultural soils. Over the course of one year (March 2016 to June 2017), 192 water samples from seven streams across Iowa and Illinois were analyzed for nitrapyrin, its metabolite 6‑chloropicolinic acid (6...
Authors
Emily Woodward, Dana W. Kolpin, Wei Zheng, Nancy L Holm, Shannon M. Meppelink, Paul J. Terrio, Michelle Hladik