Bumble bees being prepped for pesticide residue analysis at the USGS Organic Chemistry Research Laboratory (OCRL), California.
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.
Science and Products
Filter Total Items: 17
Organic Chemistry Research Core Technology Team
About the Research The Organic Chemistry Research Laboratory Core Technology Team (CTT) as part of the Environmental Health Program focuses on the identification and quantitation of trace level organic contaminants (with a special focus on pesticides) in a wide array of environmental media (water, sediment/soil, plants, biota, etc.).
A National Assessment of Pesticide, PFAS, Microplastic, and Antibiotic Resistance Gene Exposures in White-Tailed Deer
Research has documented exposures and consequential environmental health effects of pesticides, PFAS, microplastics, and antibiotic resistance genes in environmental biota. Little is known, however, regarding such effects in white-tailed deer ( Odocoileus virginianus ).
Collaborative Science Provides Understanding of Contaminants in Bottled Water-an Increasingly Common Alternate Drinking Water Source
U.S. Geological Survey researchers and public health experts collaborated to determine what contaminants occur in bottled water, which is an increasingly common alternate drinking water source, to broaden their understanding of human exposure to contaminants in drinking water supply chains. Bottled water, like public-supply and private-well tap water supply chains, contained multiple organic...
Wild Prairie Grouse Diet and Microbiomes Vary Between Cropland and Grassland Habitats
Wild prairie grouse residing in croplands had altered diets and gut microbiome imbalances characterized by a greater abundance of pathogenic bacteria and antibiotic-resistance genes in comparison to those residing in grasslands. Similar gut microbiome imbalances are rarely associated with lethal outcomes, but rather linked to sublethal health effects including growth, development, behavior, immune...
Pesticides Detected in Bees, Flowers, Soil, and Air within Pollinator-Attractive Row-Crop Border Plantings
Field study in California describes the potential for pollinator-attractive field borders in agricultural areas to become a pesticide exposure pathway to bees through soil, air, and plants.
Science to Understand Low-Level Exposures to Neonicotinoid Pesticides, their Metabolites, and Chlorinated Byproducts in Drinking Water
Scientists reported the discovery of three neonicotinoid pesticides in drinking water and their potential for transformation and removal during water treatment. The research provides new insights into the persistence of neonicotinoids and their potential for transformation during water treatment and distribution, while also identifying granulated activated carbon as a potentially effective...
Clothianidin Exposure Associated with Changes in Tadpole Behavior
During a laboratory exposure study, tadpole movement decreased with increased concentrations of clothianidin, a neonicotinoid pesticide. Decreased movement could affect a tadpole’s ability to forage, escape predation, and metamorphose before ponds dry.
Costs and Benefits of Nitrapyrin
In December 2020, our research group (as part of the Food Integrated Science Team) published a review of nitrapyrin costs and benefits in the journal Environmental Science & Technology .
Dysbiosis, immunomodulation, and health effects of agricultural pesticides in wild prairie grouse
Agrochemical pollution poses a severe threat to biodiversity. Agrochemicals can detrimentally affect wildlife growth, development, survival, reproduction, and immune responses, which facilitates emergence and spread of infectious diseases that may cause unusually high mortality. Animal microbiota plays a fundamental role in host’s food detoxification and defense against pathogens, regulates...
Environmental Management of Vector-borne Diseases
Effective management programs for vector-borne pathogens, such as West Nile Virus and the Lyme disease spirochete, are necessary to protect public health. However, some vector control methods, such as landscape manipulations and pesticide applications, can also adversely affect nontarget species and environmentally sensitive natural systems. Efficient targeting and integration of vector control...
Water-Quality Inventory Pesticides in the Golden Gate National Recreation Area
In 1998, all urban creeks in the San Francisco Bay Area were added to the Clean Water Act Section 303d list due to known or suspected diazinon impairment. Diazinon is an organophosphorus insecticide used on lawns, and fruit and vegetables. This pesticide has since been "phased out" and has not been available for purchase since late 2004. Diazinon use is declining and is being replaced by other...
Pesticide Fate Research Group (PFRG)
Pesticides are used in both agricultural and urban settings to manage unwanted plants, insects, fungi, and other pests. However, these substances and their breakdown products can move beyond their intended application sites through various means, ending up in areas where they weren't meant to be. This movement can happen via the air, through water (both surface and groundwater), and by sticking to...
Bumble bees being prepped for pesticide residue analysis.
Bumble bees being prepped for pesticide residue analysis at the USGS Organic Chemistry Research Laboratory (OCRL), California.
Water samples are extracted for pesticides.
Water samples are extracted for pesticides at the USGS Organic Chemistry Research Laboratory.
Photo credit: Elisabeth LaBarbera
Water samples are extracted for pesticides at the USGS Organic Chemistry Research Laboratory.
Photo credit: Elisabeth LaBarbera
Biosolids Analysis.
Co-extracted matrix is removed from biosolids prior to analysis at the USGS Organic Chemistry Research Laboratory (OCRL).
Photo Credit: Gabby Black.
Co-extracted matrix is removed from biosolids prior to analysis at the USGS Organic Chemistry Research Laboratory (OCRL).
Photo Credit: Gabby Black.
Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS).
Suspect screening/non-target analysis is done with LC-HRMS at the Organic Chemistry Research Laboratory (OCRL) in Sacramento, CA.
Photo credit: Michelle Hladik
Suspect screening/non-target analysis is done with LC-HRMS at the Organic Chemistry Research Laboratory (OCRL) in Sacramento, CA.
Photo credit: Michelle Hladik
Gas chromatograph-mass spectrometer (GCMS) used for pesticide analysis
Organic Chemistry Research Laboratory — Sacramento, California. Gas chromatograph-mass spectrometer - GCMS
Organic Chemistry Research Laboratory — Sacramento, California. Gas chromatograph-mass spectrometer - GCMS
Pollen samples from various plants collected from hedgerows
Organic Chemistry Research Laboratory -- Sacramento, California. Small sample bottles with pollen inside
Organic Chemistry Research Laboratory -- Sacramento, California. Small sample bottles with pollen inside
Sunflower with Bees
In a field in northern California, seen here is a sunflower with several bees. Bees are drawn to sunflowers for several compelling reasons, and understanding this attraction sheds light on both the nature of bees and the characteristics of sunflowers.
In a field in northern California, seen here is a sunflower with several bees. Bees are drawn to sunflowers for several compelling reasons, and understanding this attraction sheds light on both the nature of bees and the characteristics of sunflowers.
A U.S. Geological Survey chemist evaporating sample extracts
Organic Chemistry Research Laboratory — Sacramento, California. USGS chemist working with samples in a laboratory hood
Organic Chemistry Research Laboratory — Sacramento, California. USGS chemist working with samples in a laboratory hood
U.S. Geological Survey chemist homogenizes a tissue sample
Organic Chemistry Research Laboratory — Sacramento, California. USGS chemist homogenizes a tissue sample into a mortar and pestle
Organic Chemistry Research Laboratory — Sacramento, California. USGS chemist homogenizes a tissue sample into a mortar and pestle
Science and Products
Filter Total Items: 17
Organic Chemistry Research Core Technology Team
About the Research The Organic Chemistry Research Laboratory Core Technology Team (CTT) as part of the Environmental Health Program focuses on the identification and quantitation of trace level organic contaminants (with a special focus on pesticides) in a wide array of environmental media (water, sediment/soil, plants, biota, etc.).
A National Assessment of Pesticide, PFAS, Microplastic, and Antibiotic Resistance Gene Exposures in White-Tailed Deer
Research has documented exposures and consequential environmental health effects of pesticides, PFAS, microplastics, and antibiotic resistance genes in environmental biota. Little is known, however, regarding such effects in white-tailed deer ( Odocoileus virginianus ).
Collaborative Science Provides Understanding of Contaminants in Bottled Water-an Increasingly Common Alternate Drinking Water Source
U.S. Geological Survey researchers and public health experts collaborated to determine what contaminants occur in bottled water, which is an increasingly common alternate drinking water source, to broaden their understanding of human exposure to contaminants in drinking water supply chains. Bottled water, like public-supply and private-well tap water supply chains, contained multiple organic...
Wild Prairie Grouse Diet and Microbiomes Vary Between Cropland and Grassland Habitats
Wild prairie grouse residing in croplands had altered diets and gut microbiome imbalances characterized by a greater abundance of pathogenic bacteria and antibiotic-resistance genes in comparison to those residing in grasslands. Similar gut microbiome imbalances are rarely associated with lethal outcomes, but rather linked to sublethal health effects including growth, development, behavior, immune...
Pesticides Detected in Bees, Flowers, Soil, and Air within Pollinator-Attractive Row-Crop Border Plantings
Field study in California describes the potential for pollinator-attractive field borders in agricultural areas to become a pesticide exposure pathway to bees through soil, air, and plants.
Science to Understand Low-Level Exposures to Neonicotinoid Pesticides, their Metabolites, and Chlorinated Byproducts in Drinking Water
Scientists reported the discovery of three neonicotinoid pesticides in drinking water and their potential for transformation and removal during water treatment. The research provides new insights into the persistence of neonicotinoids and their potential for transformation during water treatment and distribution, while also identifying granulated activated carbon as a potentially effective...
Clothianidin Exposure Associated with Changes in Tadpole Behavior
During a laboratory exposure study, tadpole movement decreased with increased concentrations of clothianidin, a neonicotinoid pesticide. Decreased movement could affect a tadpole’s ability to forage, escape predation, and metamorphose before ponds dry.
Costs and Benefits of Nitrapyrin
In December 2020, our research group (as part of the Food Integrated Science Team) published a review of nitrapyrin costs and benefits in the journal Environmental Science & Technology .
Dysbiosis, immunomodulation, and health effects of agricultural pesticides in wild prairie grouse
Agrochemical pollution poses a severe threat to biodiversity. Agrochemicals can detrimentally affect wildlife growth, development, survival, reproduction, and immune responses, which facilitates emergence and spread of infectious diseases that may cause unusually high mortality. Animal microbiota plays a fundamental role in host’s food detoxification and defense against pathogens, regulates...
Environmental Management of Vector-borne Diseases
Effective management programs for vector-borne pathogens, such as West Nile Virus and the Lyme disease spirochete, are necessary to protect public health. However, some vector control methods, such as landscape manipulations and pesticide applications, can also adversely affect nontarget species and environmentally sensitive natural systems. Efficient targeting and integration of vector control...
Water-Quality Inventory Pesticides in the Golden Gate National Recreation Area
In 1998, all urban creeks in the San Francisco Bay Area were added to the Clean Water Act Section 303d list due to known or suspected diazinon impairment. Diazinon is an organophosphorus insecticide used on lawns, and fruit and vegetables. This pesticide has since been "phased out" and has not been available for purchase since late 2004. Diazinon use is declining and is being replaced by other...
Pesticide Fate Research Group (PFRG)
Pesticides are used in both agricultural and urban settings to manage unwanted plants, insects, fungi, and other pests. However, these substances and their breakdown products can move beyond their intended application sites through various means, ending up in areas where they weren't meant to be. This movement can happen via the air, through water (both surface and groundwater), and by sticking to...
Bumble bees being prepped for pesticide residue analysis.
Bumble bees being prepped for pesticide residue analysis at the USGS Organic Chemistry Research Laboratory (OCRL), California.
Bumble bees being prepped for pesticide residue analysis at the USGS Organic Chemistry Research Laboratory (OCRL), California.
Water samples are extracted for pesticides.
Water samples are extracted for pesticides at the USGS Organic Chemistry Research Laboratory.
Photo credit: Elisabeth LaBarbera
Water samples are extracted for pesticides at the USGS Organic Chemistry Research Laboratory.
Photo credit: Elisabeth LaBarbera
Biosolids Analysis.
Co-extracted matrix is removed from biosolids prior to analysis at the USGS Organic Chemistry Research Laboratory (OCRL).
Photo Credit: Gabby Black.
Co-extracted matrix is removed from biosolids prior to analysis at the USGS Organic Chemistry Research Laboratory (OCRL).
Photo Credit: Gabby Black.
Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS).
Suspect screening/non-target analysis is done with LC-HRMS at the Organic Chemistry Research Laboratory (OCRL) in Sacramento, CA.
Photo credit: Michelle Hladik
Suspect screening/non-target analysis is done with LC-HRMS at the Organic Chemistry Research Laboratory (OCRL) in Sacramento, CA.
Photo credit: Michelle Hladik
Gas chromatograph-mass spectrometer (GCMS) used for pesticide analysis
Organic Chemistry Research Laboratory — Sacramento, California. Gas chromatograph-mass spectrometer - GCMS
Organic Chemistry Research Laboratory — Sacramento, California. Gas chromatograph-mass spectrometer - GCMS
Pollen samples from various plants collected from hedgerows
Organic Chemistry Research Laboratory -- Sacramento, California. Small sample bottles with pollen inside
Organic Chemistry Research Laboratory -- Sacramento, California. Small sample bottles with pollen inside
Sunflower with Bees
In a field in northern California, seen here is a sunflower with several bees. Bees are drawn to sunflowers for several compelling reasons, and understanding this attraction sheds light on both the nature of bees and the characteristics of sunflowers.
In a field in northern California, seen here is a sunflower with several bees. Bees are drawn to sunflowers for several compelling reasons, and understanding this attraction sheds light on both the nature of bees and the characteristics of sunflowers.
A U.S. Geological Survey chemist evaporating sample extracts
Organic Chemistry Research Laboratory — Sacramento, California. USGS chemist working with samples in a laboratory hood
Organic Chemistry Research Laboratory — Sacramento, California. USGS chemist working with samples in a laboratory hood
U.S. Geological Survey chemist homogenizes a tissue sample
Organic Chemistry Research Laboratory — Sacramento, California. USGS chemist homogenizes a tissue sample into a mortar and pestle
Organic Chemistry Research Laboratory — Sacramento, California. USGS chemist homogenizes a tissue sample into a mortar and pestle