Pesticides are applied in agricultural and urban areas to control weeds, insects, fungus, and other pests. Applied pesticides and their degradates can be transported off-site through a variety of mechanisms; these pesticides can then be found in non-target areas. Pesticide transport can occur through the atmosphere, in the aqueous phase (surface and groundwater) and associated with soil/sediment. Depending on persistence and concentration, pesticides can cause adverse effects to aquatic organisms and humans. To understand pesticide exposure, it is imperative that we understand pesticide fate and transport mechanisms.
The Pesticide Fate Research Group (PFRG), located at the USGS California Water Science Center, is focused on assessing the occurrence, fate, and transport of current-use pesticides and other organic contaminants in aquatic and terrestrial environments throughout California and the nation. The PFRG is a dynamic group of chemists, hydrologists, and physical scientists, with specialized training and experience. The PFRG is involved in every aspect of the research process: field study design and sampling, analytical method development in multiple matrices (water, sediment, plants, biota), sample analysis using state of the art instrumentation, data interpretation and data management, and writing and reporting results to diverse stakeholders.
While pesticides are the main research focus of the group, the PFRG does research on other organic chemicals, using their skillset and analytical capabilities to work on a broader range of environmental contaminants including disinfection by-products, chemicals related to cannabis production, alkylphenols, etc.
The PFRG focuses on building collaborative relationships with State cooperators, researchers in academia, and scientists within the USGS and at other federal agencies. As a result of our collaborative nature, project funds come from a variety of sources: USGS mission areas such as Environmental Health (Toxic Substances Hydrology Program and Contaminant Biology Program), Ecosystems, and Water, other USGS Water Science Centers, and Cooperator sources such as California State Department of Pesticide Regulation, Water Resources Control Board, Department of Water Resources, etc.
These collaborative networks are exemplified in our Publications and in our current projects summarized on our Related Science page.
Below are other science projects associated with this project.
Neonicotinoid Seed Treatment Study
Occurrence of Current-use Pesticides in Suisun Bay and Potential Effects on Phytoplankton
Pesticide Studies in the Sacramento/San Joaquin Delta and San Francisco Bay Estuary
Pyrethroids
Pesticide Occurrence in California – Yolo Bypass Pesticide Analyses
Delta Regional Monitoring Program: Current-use Pesticides
Coordinated Pesticide Reconnaissance Study of Surface Waters in California
Pesticides in Suspended Sediment of the Alamo and New Rivers
Pesticide detections in streams throughout the foothills of the Sierra Nevada range using passive samplers from 2017 to 2019
Pesticide concentrations in surface waters of the Sacramento Valley rice-growing regions, 2010
Partitioning of six pyrethroid insecticides at varying salinities
Below are publications associated with this project.
Watershed-scale risk to aquatic organisms from complex chemical mixtures in the Shenandoah River
Juvenile African clawed frogs (Xenopus laevis) express growth, metamorphosis, mortality, gene expression, and metabolic changes when exposed to thiamethoxam and clothianidin
The silence of the clams: Forestry registered pesticides as multiple stressors on soft-shell clams
Assessing the ecological functionality and integrity of natural ponds, excavated ponds and stormwater basins for conserving amphibian diversity
Evaluation of ELISA for the analysis of imidacloprid in biological matrices: Cross-reactivities, matrix interferences, and comparison to LC-MS/MS
Cyprosulfamide: Analysis of the herbicide safener and two of its degradates in surface water and groundwater from the Midwestern United States
Pilot-scale expanded assessment of inorganic and organic tapwater exposures and predicted effects in Puerto Rico, USA
Cross-ecosystem fluxes of pesticides from prairie wetlands mediated by aquatic insect emergence: Implications for terrestrial insectivores
Field-level exposure of bumble bees to fungicides applied to a commercial cherry orchard
Prevalence of neonicotinoids and sulfoxaflor in alluvial aquifers in a high corn and soybean producing region of the Midwestern United States
Public and private tapwater: Comparative analysis of contaminant exposure and potential risk, Cape Cod, Massachusetts, USA
Exploring biophysical linkages between coastal forestry management practices and aquatic bivalve contaminant exposure
Below are news stories associated with this project.
Below are partners associated with this project.
- Overview
Pesticides are applied in agricultural and urban areas to control weeds, insects, fungus, and other pests. Applied pesticides and their degradates can be transported off-site through a variety of mechanisms; these pesticides can then be found in non-target areas. Pesticide transport can occur through the atmosphere, in the aqueous phase (surface and groundwater) and associated with soil/sediment. Depending on persistence and concentration, pesticides can cause adverse effects to aquatic organisms and humans. To understand pesticide exposure, it is imperative that we understand pesticide fate and transport mechanisms.
The above illustration lists pesticide terminology commonly used by scientists. (Click image to enlarge.) The Pesticide Fate Research Group (PFRG), located at the USGS California Water Science Center, is focused on assessing the occurrence, fate, and transport of current-use pesticides and other organic contaminants in aquatic and terrestrial environments throughout California and the nation. The PFRG is a dynamic group of chemists, hydrologists, and physical scientists, with specialized training and experience. The PFRG is involved in every aspect of the research process: field study design and sampling, analytical method development in multiple matrices (water, sediment, plants, biota), sample analysis using state of the art instrumentation, data interpretation and data management, and writing and reporting results to diverse stakeholders.
While pesticides are the main research focus of the group, the PFRG does research on other organic chemicals, using their skillset and analytical capabilities to work on a broader range of environmental contaminants including disinfection by-products, chemicals related to cannabis production, alkylphenols, etc.
The above chart shows the history of the Pesticide Fate Research Group. (Click image to enlarge.) The PFRG focuses on building collaborative relationships with State cooperators, researchers in academia, and scientists within the USGS and at other federal agencies. As a result of our collaborative nature, project funds come from a variety of sources: USGS mission areas such as Environmental Health (Toxic Substances Hydrology Program and Contaminant Biology Program), Ecosystems, and Water, other USGS Water Science Centers, and Cooperator sources such as California State Department of Pesticide Regulation, Water Resources Control Board, Department of Water Resources, etc.
These collaborative networks are exemplified in our Publications and in our current projects summarized on our Related Science page.
- Science
Below are other science projects associated with this project.
Neonicotinoid Seed Treatment Study
Neonicotinoids are a new class of insecticides chemically related to nicotine. Like nicotine, they act on receptors in the nerves and are generally much more toxic to insects, than they are to mammals and other higher organisms. Their use has increased rapidly over the last decade, driven in large part by their use for seed coating. Seed coating is when a seed is treated with an insecticide prior...Occurrence of Current-use Pesticides in Suisun Bay and Potential Effects on Phytoplankton
Suisun Bay is an area identified as critical habitat for the threatened Delta Smelt. Several important changes in the pelagic food web of this area have been documented over the last two decades indicating that food for Delta Smelt and other threatened fishes is in short.Pesticide Studies in the Sacramento/San Joaquin Delta and San Francisco Bay Estuary
The objectives of this specific study are to characterize the mixtures of current-use pesticides and pesticide degradates entering the Sacramento/San Joaquin Delta from its two main river sources over a period of 12 consecutive months.Pyrethroids
Pyrethroid insecticide use in California has been increasing in recent years. Pyrethroids are used in both agricultural and urban areas. They are of environmental concern because of their high toxicity to fish and invertebrates.Pesticide Occurrence in California – Yolo Bypass Pesticide Analyses
The project is part of an overarching Interagency Ecological Program (IEP)/Department of Water Resources (DWR) study that is focused on understanding the processes by which the Yolo Bypass may provide a fall food web supply for the Cache Slough Complex and downstream regions of the Sacramento/San Joaquin Delta. Several studies conducted since 2011 have shown that phytoplankton blooms can be...Delta Regional Monitoring Program: Current-use Pesticides
This study will utilize the unique analytical capabilities of the USGS Pesticide Fate Research Group (PFRG), Organic Chemistry Research Laboratory (OCRL) to assess the occurrence of a large suite of understudied, current-use pesticides and pesticide degradates in surface waters entering the Sacramento/San Joaquin Delta.Coordinated Pesticide Reconnaissance Study of Surface Waters in California
Pesticides are used throughout the State of California in both urban and agricultural settings and are routinely detected in surface water. Each year, new pesticides are introduced to the market and often become detected in surface water. It can take several years or more for routine monitoring programs to acquire the capability to detect new and understudied pesticides of concern because...Pesticides in Suspended Sediment of the Alamo and New Rivers
Previous studies have detected current-use pesticides and DDT metabolites in water and suspended sediments from the Alamo and New Rivers. Additional studies have found water samples from both rivers to be toxic to aquatic organisms in laboratory bioassays, and implicated certain current-use pesticides as the source of this toxicity. Recent requirements under the Clean Water Act for the Regional... - Data
Pesticide detections in streams throughout the foothills of the Sierra Nevada range using passive samplers from 2017 to 2019
This dataset was produced from analyzing Affinisep SDB-RPS, Affinisep HLB, and Restek Resprep C18 disks that were deployed with the use of Chemcatcher� passive sampling devices. Silicone bands were also deployed and used for exploring economical methods of sampling for pesticides in surface water. Sampling assemblies were deployed in streams throughout the foothills of the Sierra Nevada range andPesticide concentrations in surface waters of the Sacramento Valley rice-growing regions, 2010
Surface water samples were collected from four stream/agricultural drain sites in the Sacramento Valley of California to measure pesticides commonly applied to rice. Samples were collected weekly from May through August 2010 to capture the rice pesticide application season. Water samples were filtered (0.7 ?m) and extracted via solid-phase extraction. Additionally, the filter paper was solvent extPartitioning of six pyrethroid insecticides at varying salinities
To determine aqueous pyrethroid partitioning across a salinity gradient 20 mL Pyrex beakers were filled with 8 mL of deionized water at varying salinities (0, 0.5, 2, 6 ppt). Salinity was adjusted using a 10 ppt stock solution (made by diluting Instant Ocean into deionized water). The water samples were spiked with pyrethroids (bifenthrin, cyhalothrin, cyfluthrin, cypermethrin, deltamethrin, esfen - Publications
Below are publications associated with this project.
Filter Total Items: 102Watershed-scale risk to aquatic organisms from complex chemical mixtures in the Shenandoah River
River waters contain complex chemical mixtures derived from natural and anthropogenic sources. Aquatic organisms are exposed to the entire chemical composition of the water, resulting in potential effects at the organismal through ecosystem level. This study applied a holistic approach to assess landscape, hydrological, chemical, and biological variables. On-site mobile laboratory experiments wereAuthorsLarry Barber, Kaycee E. Faunce, David Bertolatus, Michelle Hladik, Jeramy Jasmann, Steffanie H. Keefe, Dana W. Kolpin, Michael T. Meyer, Jennifer L. Rapp, David A. Roth, Alan M. VajdaJuvenile African clawed frogs (Xenopus laevis) express growth, metamorphosis, mortality, gene expression, and metabolic changes when exposed to thiamethoxam and clothianidin
Neonicotinoids (NEO) represent the main class of insecticides currently in use, with thiamethoxam (THX) and clothianidin (CLO) primarily applied agriculturally. With few comprehensive studies having been performed with non-target amphibians, the aim was to investigate potential biomarker responses along an adverse outcome pathway of NEO exposure, whereby data were collected on multiple biologicalAuthorsJill Jenkins, Katherine R. Hartop, Ghadeer Bukhari, Debra E. Howton, Kelly Smalling, Scott Mize, Michelle Hladik, Darren Johnson, Rassa Dale, Bonnie L. BrownThe silence of the clams: Forestry registered pesticides as multiple stressors on soft-shell clams
Contaminants are ubiquitous in the environment, often reaching aquatic systems. Combinations of forestry use pesticides have been detected in both water and aquatic organism tissue samples in coastal systems. Yet, most toxicological studies focus on the effects of these pesticides individually, at high doses, and over acute time periods, which, while key for establishing toxicity and safe limits,AuthorsAlexandra G. Tissot, Elise F. Granek, Anne W Thompson, Michelle Hladik, Patrick W. Moran, Kaegen Scully-EngelmeyerAssessing 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 Smalling, Sara Breitmeyer, John F. Bunnell, Kim J Laidig, Patrick Burritt, Marilyn Sobel, Jonathan Cohl, Michelle Hladik, Kristin M. Romanok, Paul BradleyEvaluation of ELISA for the analysis of imidacloprid in biological matrices: Cross-reactivities, matrix interferences, and comparison to LC-MS/MS
Imidacloprid is among the most used pesticides worldwide and there are toxicity concerns for nontarget organisms. Accurate and sensitive methods are necessary to quantitate imidacloprid concentrations in biological matrices to better understand their fate and effects. Here we evaluated an enzyme-linked immunosorbent assay (ELISA) kit for the analysis of imidacloprid in biological samples. FollowinAuthorsMichael S. Gross, Emily Woodward, Michelle HladikCyprosulfamide: Analysis of the herbicide safener and two of its degradates in surface water and groundwater from the Midwestern United States
Herbicide safeners are commonly included in herbicide formulations to selectively protect crops from herbicide toxicity but are poorly understood in terms of their environmental occurrence and fate. This study established an analytical method for a newer safener, cyprosulfamide, and two of its degradates, cyprosulfamide desmethyl and N-cyclopropyl-4-sulfamoylbenzamide, in water via solid-phase extAuthorsMonica E McFadden, Michelle HladikPilot-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 Bradley, Ingrid Y. Padilla, Kristin Romanok, Kelly Smalling, Michael J. Focazio, Sara 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. WilsonCross-ecosystem fluxes of pesticides from prairie wetlands mediated by aquatic insect emergence: Implications for terrestrial insectivores
Contaminants alter the quantity and quality of insect prey available to terrestrial insectivores. In agricultural regions, the quantity of aquatic insects emerging from freshwaters can be impacted by insecticides originating from surrounding croplands. We hypothesized that, in such regions, adult aquatic insects could also act as vectors of pesticide transfer to terrestrial food webs. To estimateAuthorsJohanna M. Kraus, Kathryn Kuivila, Michelle Hladik, Neil Shook, David M. Mushet, Kelen Dowdy, Rachel HarringtonField-level exposure of bumble bees to fungicides applied to a commercial cherry orchard
Bumble bees, Bombus spp. (Apidae), are important native pollinators; however, populations of some species are declining in North America and agricultural chemicals are a potential cause. Fungicides are generally not highly toxic to bees, but little is known about sublethal or synergistic effects. This study evaluates bumble bee exposure to fungicides by quantifying concentrations of boscalid and pAuthorsKathryn M. Kuivila, Houston Judd, Michelle Hladik, James P. StrangePrevalence of neonicotinoids and sulfoxaflor in alluvial aquifers in a high corn and soybean producing region of the Midwestern United States
Neonicotinoids have been previously detected in Iowa surface waters, but less is known regarding their occurrence in groundwater. To help fill this research gap, a groundwater study was conducted in eastern Iowa and southeastern Minnesota, a corn and soybean producing area with known heavy neonicotinoid use. Neonicotinoids were studied in alluvial aquifers, a hydrogeologic setting known to be vulnAuthorsD.A. Thompson, Dana W. Kolpin, Michelle Hladik, Kimberlee K. Barnes, J.D. Vargo, R.W. FieldPublic and private tapwater: Comparative analysis of contaminant exposure and potential risk, Cape Cod, Massachusetts, USA
BackgroundHumans are primary drivers of environmental contamination worldwide, including in drinking-water resources. In the United States (US), federal and state agencies regulate and monitor public-supply drinking water while private-supply monitoring is rare; the current lack of directly comparable information on contaminant-mixture exposures and risks between private- and public-supplies underAuthorsPaul Bradley, Denis R. LeBlanc, Kristin Romanok, Kelly Smalling, Michael J. Focazio, Mary C. Cardon, Jimmy Clark, Justin M. Conley, Nicola Evans, Carrie E Givens, James L. Gray, L. Earl Gray, Phillip C. Hartig, Christopher P. Higgins, Michelle Hladik, Luke R. Iwanowicz, Keith Loftin, R. Blaine McCleskey, Carrie A. McDonough, Elizabeth Medlock-Kakaley, Christopher P. Weis, Vickie S. WilsonByEcosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Eastern Ecological Science Center, New England Water Science Center, New Jersey Water Science Center, South Atlantic Water Science Center (SAWSC), Upper Midwest Water Science Center, National Water Quality LaboratoryExploring biophysical linkages between coastal forestry management practices and aquatic bivalve contaminant exposure
Terrestrial land use activities present cross-ecosystem threats to riverine and marine species and processes. Specifically, pesticide runoff can disrupt hormonal, reproductive, and developmental processes in aquatic organisms, yet non-point source pollution is difficult to trace and quantify. In Oregon, U.S.A., state and federal forestry pesticide regulations, designed to meet regulatory water quaAuthorsKaegan Scully-Engelmeyer, Elise F. Granek, Max Nielsen-Pincus, Andy Lanier, Steven S Rumrill, Patrick W. Moran, Elena Nilsen, Michelle Hladik, Lori Pillsbury - News
Below are news stories associated with this project.
- Partners
Below are partners associated with this project.