Temporal trends of exposure to the herbicide glyphosate in the United States (2013-2018): Data from the National Health and Nutrition Examination Survey.

Glyphosate, the most widely used herbicide in the United States, is applied to control broadleaf weeds and grasses. Public concern is mounting over how pesticides affect human and environmental health. Glyphosate toxicity in animals is known, but human carcinogenicity is controversial, and limited epidemiologic evidence suggests associations between exposure and respiratory diseases (e.

Online solid phase extraction high-performance liquid chromatography - Isotope dilution - Tandem mass spectrometry quantification of organophosphate pesticides, synthetic pyrethroids, and selected herbicide metabolites in human urine.

Analytical methods to quantify pesticide biomarkers in human population studies are critical for exposure assessment given the widespread use of pesticides for pest and weed control and their potential for affecting human health. We developed a method to quantify, in 0.2 mL of urine, concentrations of 10 pesticide biomarkers: four organophosphate insecticide metabolites (3,5,6-trichloro-2-pyridinol (TCPy), 2-isopropyl-6-methyl-4-pyrimidinol, para-nitrophenol, malathion dicarboxylic acid); five synthetic pyrethroid insecticide metabolites (4-fluoro-3-phenoxybenzoic acid, 3-phenoxybenzoic acid, cis and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (DCCA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid); and the herbicide 2,4-dichlorophenoxyacetic acid.

Exposure to glyphosate in the United States: Data from the 2013-2014 National Health and Nutrition Examination Survey.

Background: Exposure to glyphosate, the most used herbicide in the United States, is not well characterized. We assessed glyphosate exposure in a representative sample of the U.S.

Quantification of glyphosate and other organophosphorus compounds in human urine via ion chromatography isotope dilution tandem mass spectrometry.

Organophosphorus pesticides are the most used pesticides in the United States. Most organophosphorus pesticides are composed of a phosphate (or phosphorothioate or phosphorodithioate) moiety and a variable organic group. Organophosphorus pesticides are scrutinized by regulatory bodies and agencies because of their toxicity or suspected carcinogenicity.

Quantification of 16 urinary biomarkers of exposure to flame retardants, plasticizers, and organophosphate insecticides for biomonitoring studies.

Chlorinated alkyl and non-chlorinated aryl organophosphate flame retardants (OPFRs) and some brominated flame retardants (FR) were introduced as replacements for polybrominated diphenyl ethers (PBDEs) after PBDEs phase-out in 2004 and 2013. Organophosphorous (OP) insecticides are mainly used in agricultural settings since the Food Quality Protection Act of 1996 phased-out most residential uses of OP insecticides in the United States. Urinary metabolites of FRs and OPs are known exposure biomarkers to FRs and OP insecticides, respectively.

Quantification of DEET and neonicotinoid pesticide biomarkers in human urine by online solid-phase extraction high-performance liquid chromatography-tandem mass spectrometry.

Neonicotinoid insecticides are widely used replacements for organophosphate and carbamate insecticides, but the extent of human exposure is largely unknown. On the other hand, based on urinary concentrations of DEET metabolites, human exposure to N,N-diethyl-m-toluamide (DEET) appears to be widespread. We developed a fast online solid-phase extraction high-performance liquid chromatography-isotope dilution tandem mass spectrometry (HPLC-MS/MS) method to measure in 200 μL of human urine the concentrations of six neonicotinoid biomarkers (acetamiprid, N-desmethyl-acetamiprid, clothianidin, imidacloprid, 5-hydroxy-imidacloprid, thiacloprid), and two DEET biomarkers (3-diethyl-carbamoyl benzoic acid, 3-ethyl-carbamoyl benzoic acid).

Serum Total Testosterone Concentrations in the US Household Population from the NHANES 2011-2012 Study Population.

Background: Limited information is available about testosterone concentrations representative of the general US population, especially children, women, and non-Hispanic Asians.

Methods: We obtained nationally representative data for total testosterone (totalT), measured with standardized LC-MS/MS, for the US population age 6 years and older from the 2011-2012 National Health and Nutrition Examination Survey (NHANES). We analyzed 6746 serum samples and calculated the geometric means, distribution percentiles, and covariate-adjusted geometric means by age, sex, and race/ethnicity.

High variability in serum estradiol measurements in men and women.

To reduce the variability in estradiol (E2) testing and to assure better patient care, standardization of E2 measurements has been recommended. This study aims to assess the accuracy and variability of E2 measurements performed by 11 routine immunological methods and 6 mass spectrometry methods using single donor serum materials and to compare the results to a reference method. The contribution of calibration bias, specificity or matrix effects, and imprecision on the overall variability of individual assays was evaluated.