A5054264185- Effects and risks of endocrine disrupting chemicals
- Toxic Organic Pollutants Impact
- Per- and polyfluoroalkyl substances research
- Environmental Toxicology and Ecotoxicology
- Pharmaceutical and Antibiotic Environmental Impacts
- Carcinogens and Genotoxicity Assessment
- Pluripotent Stem Cells Research
- Water Treatment and Disinfection
- Selenium in Biological Systems
- Mercury impact and mitigation studies
- Sexual Differentiation and Disorders
- Analytical chemistry methods development
- Chemical Analysis and Environmental Impact
- Freshwater macroinvertebrate diversity and ecology
- Gestational Diabetes Research and Management
- Atmospheric chemistry and aerosols
- Smart Materials for Construction
- Heavy metals in environment
- Reproductive Biology and Fertility
- Fecal contamination and water quality
- Physiological and biochemical adaptations
- Aquatic Invertebrate Ecology and Behavior
- Genetically Modified Organisms Research
- Peroxisome Proliferator-Activated Receptors
- Mine drainage and remediation techniques
Environmental Protection Agency
2016-2024
Research Triangle Park Foundation
2016-2024
Southern Research Institute
2018
North Carolina State University
2009-2017
Oak Ridge Associated Universities
2016
Oak Ridge Institute for Science and Education
2016
University of Tennessee at Chattanooga
2008-2009
Stroud Water Research Center
2009
University of Manitoba
2009
Hexafluoropropylene oxide dimer acid [(HFPO-DA), GenX] is a member of the per- and polyfluoroalkyl substances (PFAS) chemical class, elevated levels HFPO-DA have been detected in surface water, air, treated drinking water United States Europe.We aimed to characterize potential maternal postnatal toxicities oral rats during sexual differentiation. Given that some PFAS activate peroxisome proliferator-activated receptors (PPARs), we sought assess whether affects androgen-dependent development...
Hexafluoropropylene oxide dimer acid (HFPO-DA or GenX) is an industrial replacement for the straight-chain perfluoroalkyl substance (PFAS), perfluorooctanoic (PFOA). Previously we reported maternal, fetal, and postnatal effects from gestation day (GD) 14-18 oral dosing in Sprague-Dawley rats. Here, further evaluated perinatal toxicity of HFPO-DA by orally rat dams with 1-125 mg/kg/d (n = 4 litters per dose) GD16-20 10-250 5) GD8 - (PND) 2. Effects were similar to those previously GD14-18...
In vitro bioassays are sensitive, effect-based tools used to quantitatively screen for chemicals with nuclear receptor activity in environmental samples. We measured estrogen (ER), androgen (AR), and glucocorticoid (GR) activity, along a broad suite of chemical analytes, streamwater from 35 well-characterized sites (3 reference 32 impacted) across 24 states Puerto Rico. ER agonism was the most frequently detected nearly all (34/35) displaying (range, 0.054-116 ng E2Eq L
Selenium contamination in aquatic ecosystems provides management challenges because bioaccumulation animals is largely a function of dietary exposure, whereas regulatory entities have traditionally focused on direct water to organism interactions. known be readily absorbed by primary producers and can potentially biomagnify food webs elicit adverse effects higher trophic levels. However, selenium the invertebrate prey many predatory poorly understood. Here, we used 75Se (as selenite) as...
Abstract In previous laboratory chronic 7‐d toxicity tests conducted with the cladoceran Ceriodaphnia dubia , surface waters collected from Appalachian sites impacted by coal mining have shown toxic effects associated elevated total dissolved solids (TDS). The objective of present study was to evaluate major ions in C . (7‐d exposure), a unionid mussel ( Lampsilis siliquoidea ; 28‐d an amphipod Hyalella azteca and mayfly Centroptilum triangulifer 35‐d exposure) 3 reconstituted designed be...
Biomonitoring efforts have clearly shown that all humans are exposed to chemical mixtures. Of concern is whether or not exposure mixtures during pregnancy contributes congenital abnormalities in children even when each at an individual dose does affect the fetus. Here, we hypothesized utero a mixture of chemicals covering multiple "antiandrogenic" mechanisms action doses individually no adverse effect would result permanent reproductive tract alterations male rat after birth. Pregnant dams...
Humans carry residues of multiple synthetic chemicals at any given point in time. Research has demonstrated that compounds with varying molecular initiating events (MIE) disrupt common key can act concert to produce cumulative adverse effects. Congenital defects the male reproductive tract are some most frequently diagnosed malformations humans and chemical exposures utero these effects laboratory animals humans. Here, we hypothesized exposure a mixture pesticides phthalates, each which...
Nafion byproduct 2 (NBP2) is a polyfluoroalkyl ether sulfonic acid that was recently detected in surface water, drinking and human serum samples from monitoring studies North Carolina, USA. We orally exposed pregnant Sprague-Dawley rats to NBP2 gestation day (GD) 14-18 (0.1-30 mg/kg/d), GD17-21, GD8 postnatal (PND) (0.3-30 mg/kg/d) characterize maternal, fetal, effects. GD14-18 exposures were also conducted with perfluorooctane sulfonate (PFOS) for comparison NBP2, as well data previously...
Globally, biomonitoring data demonstrate virtually all humans carry residues of multiple per- and polyfluoroalkyl substances (PFAS). Despite pervasive co-exposure, limited mixtures-based in vivo PFAS toxicity research has been conducted. Perfluorooctanoic acid (PFOA) perfluorooctane sulfonic (PFOS) are commonly detected human environmental samples both produce adverse effects laboratory animal studies, including maternal offspring when orally administered during pregnancy lactation. To...
Perfluoro-2-methoxyacetic acid (PFMOAA) is a short-chain perfluoroalkyl ether carboxylic that has been detected at high concentrations (∼10 μg/L) in drinking water eastern North Carolina, USA, and human serum breastmilk China. Despite documented exposure there are almost no toxicity data available to inform risk assessment of PFMOAA. Here we exposed pregnant Sprague–Dawley rats range PFMOAA doses (10–450 mg/kg/d) via oral gavage from gestation day (GD) 8 postnatal (PND) 2 compared results...
In vitro estrogen receptor assays are valuable tools for identifying environmental samples and chemicals that display estrogenic activity. However, in potency cannot necessarily be extrapolated to estimates of vivo because currently unable fully account absorption, distribution, metabolism, excretion. To explore this issue, we calculated relative factors (RPF), using 17α-ethinyl estradiol (EE2) as the reference compound, several mixtures T47D-KBluc transactivation assay. RPFs were used...
Humans are primary drivers of environmental contamination worldwide, including in drinking-water resources. In the United States (US), federal and state agencies regulate monitor public-supply drinking water while private-supply monitoring is rare; current lack directly comparable information on contaminant-mixture exposures risks between private- public-supplies undermines tapwater (TW) consumer decision-making.We compared residential point-of-use TW at Cape Cod, Massachusetts, where both...
Little is known about the bioaccumulation dynamics, biotransformation processes, or subsequent toxicity to consumers of dissolved selenite (SeO3) versus selenate (SeO4) uptake into aquatic primary producer communities. To address these data gaps, we examined SeO3 and SeO4 bioconcentration complex freshwater periphyton communities under static static-renewal conditions. Further, explored Se species using X-ray absorption near edge structure (XANES) spectroscopy analysis changes in associated...
A pilot-scale expanded target assessment of mixtures inorganic and organic contaminants in point-of-consumption drinking water (tapwater, TW) was conducted Puerto Rico (PR) to continue inform TW exposures corresponding estimations cumulative human-health risks across the US. In August 2018, a spatial synoptic pilot than 524 37 chemicals 14 locations (7 home; 7 commercial) PR. follow-up 3-day temporal variability December 2018 at two (1 home, 1 included daily pre- post-flush samples....
Selenium (Se) trafficking in oviparous species remains understudied and a major source of uncertainty developing sound Se regulations. Here, we utilized 75Se to follow through simulated natural food chain (water, periphyton, mayflies (Centroptilum triangulifer), fish (Japanese medaka)). We specifically examined assimilation efficiency, tissue distribution, efflux rate, maternal transfer medaka. efficiency (AE) averaged 63.2 ± 8.8% from mayfly diets was not affected by [Se] across dietary...