91 research outputs found

    Characterization of Environmental Levels of Pesticide Residues in Household Air and Dust Samples near a Bioenergy Plant Using Treated Seed as Feedstock

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    Exposure to neonicotinoid insecticides is associated with adverse human health outcomes. There is environmental contamination in Saunders County, Nebraska, due to the accumulation of fungicides and insecticides from a now-closed ethanol plant using seed corn as stock. A pilot study quantified environmental contamination in nearby houses from residual pesticides by measuring dust and air (indoor/outdoor) concentrations of neonicotinoids and fungicides at the study site (households within two miles of the plant) and control towns (20–30 miles away). Air (SASS® 2300 Wetted-Wall Air Sampler) and surface dust (GHOST wipes with 4 × 4-inch template) samples were collected from eleven study households and six controls. Targeted analysis quantified 13 neonicotinoids, their transformation products and seven fungicides. Sample extracts were concentrated using solid phase extraction (SPE) cartridges, eluted with methanol and evaporated. Residues were redissolved in methanol–water (1:4) prior to analysis, with an Acquity H-Class ultraperformance liquid chromatograph (UPLC) and a Xevo triple quadrupole mass spectrometer. We compared differences across chemicals in air and surface dust samples at the study and control sites by dichotomizing concentrations above or below the detection limit, using Fisher’s exact test. A relatively higher detection frequency was observed for clothianidin and thiamethoxam at the study site for the surface dust samples, similarly for thiamethoxam in the air samples. Our results suggest airborne contamination (neonicotinoids and fungicides) from the ethanol facility at houses near the pesticide contamination

    Biomarkers of Toxic Exposure and Oxidative Stress Among U.S. Adult Users of Premium Cigar Versus Other Cigar Subtypes: 2013-2019

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    INTRODUCTION: Cigars are currently the second-highest-used combustible tobacco product among U.S. adults, but knowledge about health effects of premium cigars versus other cigar subtype use is limited. AIMS AND METHODS: This study analyzed the biospecimen data (n = 31 875) from Waves 1-5 of the Population Assessment of Tobacco and Health Study, collected during 2013-2019. Multivariable generalized estimation equations, accounting for within-person clustering, were conducted to examine differences in urine biomarkers of exposure (BOE) from five classes of harmful and potentially harmful constituents along with a biomarker of oxidative stress (urine 8-isoprostane) among exclusive users of premium cigars versus other exclusive cigar subtypes (ie, non-premium large cigars, cigarillos, and filtered cigars), cigarettes, and non-tobacco users. RESULTS: In comparison to non-tobacco users, exclusive premium cigar users had higher geometric mean concentrations of the nicotine metabolite cotinine (5.8 vs. 0.5ng/mg, p \u3c .0001), tobacco-specific nitrosamine (TSNA) (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL): 7.8 vs. 1.3pg/mg, p \u3c .0001), and volatile organic compound (VOC) (N-Acetyl-S-(2-cyanoethyl)-L-cysteine (CYMA, acrylonitrile): 4.7 vs. 1.6ng/mg, p \u3c .0001). Exclusive premium cigar users were less likely to be daily users than other tobacco user groups and had comparable BOEs with exclusive non-premium large cigar users but generally lower BOEs than exclusive cigarillo, filtered cigar, and cigarette smokers. Daily exclusive premium cigar users had similar nicotine and TSNA exposure but lower exposure to polycyclic aromatic hydrocarbons and volatile organic compounds than exclusive cigarillo and filtered cigar users. CONCLUSIONS: Premium cigar use exhibits different exposure to toxicants from other cigar subtype users. Regulations of premium cigars need to formalize product definition and take the population\u27s health effects into consideration. IMPLICATIONS: This population study provides important information on BOE and potential harm with premium cigar use and its potential health effects. At present, premium cigars appear to pose a relatively low overall population health risk due to low frequency of use. However, future regulation of other tobacco products might change the landscape of premium cigar use and alter the overall health impact

    Urine Biomarkers of Risk in the Molecular Etiology of Breast Cancer

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    Endogenous estrogens can be bio-activated to endogenous carcinogens via formation of estrogen quinones. Estrogen-3,4-quinones react with DNA to form mutagenic depurinating estrogen-DNA adducts. The carcinogenicity of endogenous estrogens is related to unbalanced estrogen metabolism leading to excess estrogen quinones and formation of depurinating DNA adducts. The present studies were initiated to confirm that relatively high levels of depurinating estrogen-DNA adducts are present in women at high risk for breast cancer or diagnosed with the disease. These adducts may be biomarkers for early detection of breast cancer risk. The estrogen metabolites, conjugates and depurinating DNA adducts were identified and quantified by using ultraperformance liquid chromatography/tandem mass spectrometry to analyze urine samples from 40 healthy control women, 40 high-risk women and 40 women with newly diagnosed breast cancer. Estrogen metabolism was shifted from protective methoxylation and conjugation pathways in healthy control women towards activating pathways leading to formation of depurinating DNA adducts in women at high risk or with breast cancer. These results support the hypothesis that breast cancer is initiated by mutations derived from depurination of estrogen-DNA adducts. Therefore, relative levels of depurinating estrogen-DNA adducts could become biomarkers for early detection of breast cancer risk and aid in determining preventive strategies

    Joint association between ambient air pollutant mixture and pediatric asthma exacerbations

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    Background: Exposure to air pollutants is known to exacerbate asthma, with prior studies focused on associations between single pollutant exposure and asthma exacerbations. As air pollutants often exist as a complex mixture, there is a gap in understanding the association between complex air pollutant mixtures and asthma exacerbations. We evaluated the association between the air pollutant mixture (52 pollutants) and pediatric asthma exacerbations. Method: This study focused on children (age ≤ 19 years) who lived in Douglas County, Nebraska, during 2016–2019. A seasonal- scale joint association between the outdoor air pollutant mixture adjusting for potential confounders (temperature, precipitation, wind speed, and wind direction) in relation to pediatric asthma exacerbation-related emergency department (ED) visits was evaluated using the generalized weighted quantile sum (qWQS) regression with repeated holdout validation. Results: We observed associations between air pollutant mixture and pediatric asthma exacerbations during spring (lagged by 5 days), summer (lag 0–5 days), and fall (lag 1–3 days) seasons. The estimate of the joint outdoor air pollutant mixture effect was higher during the summer season (adjusted-βWQS = 1.11, 95% confidence interval [CI]: 0.66, 1.55), followed by spring (adjusted-βWQS = 0.40, 95% CI: 0.16, 0.62) and fall (adjusted-βWQS = 0.20, 95% CI: 0.06, 0.33) seasons. Among the air pollutants, PM2.5, pollen, and mold contributed higher weight to the air pollutant mixture. Conclusion: There were associations between outdoor air pollutant mixture and pediatric asthma exacerbations during the spring, summer, and fall seasons. Among the 52 outdoor air pollutant metrics investigated, PM2.5, pollen (sycamore, grass, cedar), and mold (Helminthosporium, Peronospora, and Erysiphe) contributed the highest weight to the air pollutant mixture

    Low-Level Groundwater Atrazine in High Atrazine Usage Nebraska Counties: Likely Effects of Excessive Groundwater Abstraction

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    Recent studies observed a correlation between estrogen-related cancers and groundwater atrazine in eastern Nebraska counties. However, the mechanisms of human exposure to atrazine are unclear because low groundwater atrazine concentration was observed in counties with high cancer incidence despite having the highest atrazine usage. We studied groundwater atrazine fate in high atrazine usage Nebraska counties. Data were collected from Quality Assessed Agrichemical Contaminant Nebraska Groundwater, Parameter–Elevation Regressions on Independent Slopes Model (PRISM), and water use databases. Descriptive statistics and cluster analysis were performed. Domestic wells (59%) were the predominant well type. Groundwater atrazine was affected by well depth. Clusters consisting of wells with low atrazine were characterized by excessive groundwater abstraction, reduced precipitation, high population, discharge areas, and metropolitan counties. Hence, low groundwater atrazine may be due to excessive groundwater abstraction accompanied by atrazine. Human exposure to atrazine in abstracted groundwater may be higher than the estimated amount in groundwater

    Geospatial Distribution of Age-Adjusted Incidence of the Three Major Types of Pediatric Cancers and Waterborne Agrichemicals in Nebraska

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    This study was conducted to examine, at the county level, the relationship between pediatric cancer incidence rate and atrazine and nitrate mean concentrations in surface and groundwater. A negative binomial regression analysis was performed to investigate the association between central nervous system (CNS) tumors, leukemia, lymphoma, and atrazine and nitrate mean concentrations in groundwater. The age-adjusted brain and other CNS cancer incidence was higher than the national average in 63% of the Nebraska counties. After controlling for the counties socio-economic status and nitrate concentrations in groundwater, counties with groundwater atrazine concentrations above 0.0002 μg/L had a higher incidence rate for pediatric cancers (brain and other CNS, leukemia, and lymphoma) compared to counties with groundwater atrazine concentrations in the reference group (0.0000–0.0002 μg/L). Additionally, compared to counties with groundwater nitrate concentrations between 0 and 2 mg/L (reference group), counties with groundwater nitrate concentrations between 2.1 and 5 mg/L (group 2) had a higher incidence rate for pediatric brain and other CNS cancers (IRR = 8.39; 95% CI: 8.24–8.54), leukemia (IRR = 7.35; 95% CI: 7.22–7.48), and lymphoma (IRR = 5.59; CI: 5.48–5.69) after adjusting for atrazine groundwater concentration and the county socioeconomic status. While these findings do not indicate a causal relationship, because other contaminants or cancer risk factors have not been accounted for, they suggest that atrazine and nitrate may pose a risk relative to the genesis of pediatric brain and CNS cancers, leukemia, and lymphoma

    Using Watershed Boundaries to Map Adverse Health Outcomes: Examples From Nebraska, USA

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    In 2009, a paper was published suggesting that watersheds provide a geospatial platform for establishing linkages between aquatic contaminants, the health of the environment, and human health. This article is a follow-up to that original article. From an environmental perspective, watersheds segregate landscapes into geospatial units that may be relevant to human health outcomes. From an epidemiologic perspective, the watershed concept places anthropogenic health data into a geospatial framework that has environmental relevance. Research discussed in this article includes information gathered from the literature, as well as recent data collected and analyzed by this research group. It is our contention that the use of watersheds to stratify geospatial information may be both environmentally and epidemiologically valuable

    Impact of naturally spawning captive-bred Atlantic salmon on wild populations: depressed recruitment and increased risk of climate-mediated extinction

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    The assessment report of the 4th International Panel on Climate Change confirms that global warming is strongly affecting biological systems and that 20–30% of species risk extinction from projected future increases in temperature. It is essential that any measures taken to conserve individual species and their constituent populations against climate-mediated declines are appropriate. The release of captive bred animals to augment wild populations is a widespread management strategy for many species but has proven controversial. Using a regression model based on a 37-year study of wild and sea ranched Atlantic salmon (Salmo salar) spawning together in the wild, we show that the escape of captive bred animals into the wild can substantially depress recruitment and more specifically disrupt the capacity of natural populations to adapt to higher winter water temperatures associated with climate variability. We speculate the mechanisms underlying this seasonal response and suggest that an explanation based on bio-energetic processes with physiological responses synchronized by photoperiod is plausible. Furthermore, we predict, by running the model forward using projected future climate scenarios, that these cultured fish substantially increase the risk of extinction for the studied population within 20 generations. In contrast, we show that positive outcomes to climate change are possible if captive bred animals are prevented from breeding in the wild. Rather than imposing an additional genetic load on wild populations by releasing maladapted captive bred animals, we propose that conservation efforts should focus on optimizing conditions for adaptation to occur by reducing exploitation and protecting critical habitats. Our findings are likely to hold true for most poikilothermic species where captive breeding programmes are used in population management

    Public Health Aspects of the Daugherty Water for Food Institute Strategic Plan

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    The University of Nebraska College of Public Health is committed to contributing to the research, service and education programs of the Daugherty Water for Food Institute. The College can offer a wide variety of expertise that can contribute to programs related to water, food and health. This document has been written to highlight the areas in which College faculty have particular interests, knowledge and experience to contribute.https://digitalcommons.unmc.edu/coph_reports/1000/thumbnail.jp

    Tetra-methoxystilbene modulates ductal growth of the developing murine mammary gland

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    Extensive data suggest that estradiol contributes to the development of breast cancer by acting as a mitogen and exerting direct genotoxic effects after enzymatic conversion to 4-hydroxyestradiol (4-OHE2) via cytochrome P450 1B1 (CYP1B1). The mammary gland, ovary, and uterus all express CYP1B1. Overexpression of this enzyme has been associated with an increased risk of breast cancer and blockade might reduce this carcinogenic effect. For this reason, we conducted systematic in vitro and in vivo studies of a CYP1B1 inhibitor, TMS (2,3',4,5'-tetramethoxystilbene). We found that TMS blocked the enzymatic conversion of radiolabeled estradiol to both 2-hydroxyestradiol (2-OHE2) and 4-OHE2, but did not inhibit Cyp1b1 message formation. In vivo studies using mass spectrometry showed that TMS inhibited formation of 2-OHE2 and 4-OHE2 and the resulting estrogen-DNA adducts. To examine its biologic actions in vivo, we investigated whether TMS could block the hyperplastic changes that occur in the developing breast of aromatase-transfected mice. We found that TMS induced a significant reduction of ductal structures in mice less than 6 months in age. In older mice, no reduction in breast morphology occurred. These latter studies uncovered unexpected estrogen agonistic actions of TMS at high doses, including a paradoxical stimulation of breast ductal structures and the endometrium. These studies suggest that the enzyme inhibitory properties of TMS, as well as the effects on developing breast, could implicate a role for TMS in breast cancer prevention, but only in low doses and on developing breast
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