51 research outputs found

    Moderating Effect of the Neighborhood Physical Activity Environment on the Relation Between Psychosocial Factors and Physical Activity in Children: A Longitudinal Study

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    Background Few studies have examined the moderating role of neighbourhood environments on the relation between psychosocial factors and physical activity, and results of these studies are mixed. This study examined this relationship in 636 fifth to seventh graders from South Carolina, USA. Methods From 2010 to 2013, children and their parent/guardian completed annual self-reported surveys assessing psychosocial factors, and children wore accelerometers for 1 week each year. Neighbourhood environments were classified as supportive or non-supportive for physical activity (PA) based on in-person audits of facilities near children’s homes and windshield surveys of children’s streets. Growth curve analyses were completed to assess the moderating effect of the neighbourhood physical activity environment (NPAE) on the relation between psychosocial factors and total physical activity (TPA) over time. Results Significant interactions on TPA were found for (1) time, NPAE and parent-reported parent support for PA; (2) time, NPAE and child-reported equipment in the home; (3) child-reported parental support for PA and time; (4) child-reported parental support for PA and NPAE; (5) PA self-schema and time and (6) child-reported parental encouragement and time. Parental support and a supportive NPAE were important for TPA, especially as children transitioned to middle school, whereas home equipment and a supportive NPAE were important for fifth graders’ TPA. Conclusion Consistent with the socioecological model, PA behaviour was dependent on interacting effects across levels of influence. Generally, both a supportive NPAE and positive psychosocial factors were needed to support TPA. Factors influencing PA across multiple levels should be addressed in PA interventions

    Biomonitoring Data for 2,4-Dichlorophenoxyacetic Acid in the United States and Canada: Interpretation in a Public Health Risk Assessment Context Using Biomonitoring Equivalents

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    Background: Several extensive studies of exposure to 2,4- dichlorophenoxyacetic acid (2,4-D) using urinary concentrations in samples from the general population, farm applicators, and farm family members are now available. Reference doses (RfDs) exist for 2,4-D, and Biomonitoring Equivalents (BEs; concentrations in urine or plasma that are consistent with those RfDs) for 2,4-D have recently been derived and published. Objective: We reviewed the available biomonitoring data for 2,4-D from the United States and Canada and compared them with BE values to draw conclusions regarding the margin of safety for 2,4-D exposures within each population group. Data sources: Data on urinary 2,4-D excretion in general and target populations from recent published studies are tabulated and the derivation of BE values for 2,4-D summarized. Data synthesis: The biomonitoring data indicate margins of safety (ratio of BE value to biomarker concentration) of approximately 200 at the central tendency and 50 at the extremes in the general population. Median exposures for applicators and their family members during periods of use appear to be well within acute exposure guidance values. Conclusions: Biomonitoring data from these studies indicate that current exposures to 2,4-D are below applicable exposure guidance values. This review demonstrates the value of biomonitoring data in assessing population exposures in the context of existing risk assessments using the BE approach. Risk managers can use this approach to integrate the available biomonitoring data into an overall assessment of current risk management practices for 2,4-D

    Review of Pesticide Urinary Biomarker Measurements from Selected US EPA Children’s Observational Exposure Studies

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    Children are exposed to a wide variety of pesticides originating from both outdoor and indoor sources. Several studies were conducted or funded by the EPA over the past decade to investigate children’s exposure to organophosphate and pyrethroid pesticides and the factors that impact their exposures. Urinary metabolite concentration measurements from these studies are consolidated here to identify trends, spatial and temporal patterns, and areas where further research is required. Namely, concentrations of the metabolites of chlorpyrifos (3,5,6-trichloro-2-pyridinol or TCPy), diazinon (2-isopropyl-6-methyl-4-pyrimidinol or IMP), and permethrin (3-phenoxybenzoic acid or 3-PBA) are presented. Information on the kinetic parameters describing absorption and elimination in humans is also presented to aid in interpretation. Metabolite concentrations varied more dramatically across studies for 3-PBA and IMP than for TCPy, with TCPy concentrations about an order of magnitude higher than the 3-PBA concentrations. Temporal variability was high for all metabolites with urinary 3-PBA concentrations slightly more consistent over time than the TCPy concentrations. Urinary biomarker levels provided only limited evidence of applications. The observed relationships between urinary metabolite levels and estimates of pesticide intake may be affected by differences in the contribution of each exposure route to total intake, which may vary with exposure intensity and across individuals

    Genome-wide meta-analysis of problematic alcohol use in 435,563 individuals yields insights into biology and relationships with other traits

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    Problematic alcohol use (PAU) is a leading cause of death and disability worldwide. Although genome-wide association studies have identified PAU risk genes, the genetic architecture of this trait is not fully understood. We conducted a proxy-phenotype meta-analysis of PAU, combining alcohol use disorder and problematic drinking, in 435,563 European-ancestry individuals. We identified 29 independent risk variants, 19 of them novel. PAU was genetically correlated with 138 phenotypes, including substance use and psychiatric traits. Phenome-wide polygenic risk score analysis in an independent biobank sample (BioVU, n = 67,589) confirmed the genetic correlations between PAU and substance use and psychiatric disorders. Genetic heritability of PAU was enriched in brain and in conserved and regulatory genomic regions. Mendelian randomization suggested causal effects on liability to PAU of substance use, psychiatric status, risk-taking behavior and cognitive performance. In summary, this large PAU meta-analysis identified novel risk loci and revealed genetic relationships with numerous other traits

    A longitudinal study of patients with cirrhosis treated with L-ornithine L-aspartate, examined with magnetization transfer, diffusion-weighted imaging and magnetic resonance spectroscopy

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    The presence of overt hepatic encephalopathy (HE) is associated with structural, metabolic and functional changes in the brain discernible by use of a variety of magnetic resonance (MR) techniques. The changes in patients with minimal HE are less well documented. Twenty-two patients with well-compensated cirrhosis, seven of whom had minimal HE, were examined with cerebral 3 Tesla MR techniques, including T1- and T2-weighted, magnetization transfer and diffusion-weighted imaging and proton magnetic resonance spectroscopy sequences. Studies were repeated after a 4-week course of oral L-ornithine L-aspartate (LOLA). Results were compared with data obtained from 22 aged-matched healthy controls. There was no difference in mean total brain volume between patients and controls at baseline. Mean cerebral magnetization transfer ratios were significantly reduced in the globus pallidus and thalamus in the patients with cirrhosis irrespective of neuropsychiatric status; the mean ratio was significantly reduced in the frontal white matter in patients with minimal HE compared with healthy controls but not when compared with their unimpaired counterparts. There were no significant differences in either the median apparent diffusion coefficients or the mean fractional anisotropy, calculated from the diffusion-weighted imaging, or in the mean basal ganglia metabolite ratios between patients and controls. Psychometric performance improved in 50% of patients with minimal HE following LOLA, but no significant changes were observed in brain volumes, cerebral magnetization transfer ratios, the diffusion weighted imaging variables or the cerebral metabolite ratios. MR variables, as applied in this study, do not identify patients with minimal HE, nor do they reflect changes in psychometric performance following LOLA

    Dietary Pyrethroid Exposures and Intake Doses for 188 Duplicate-Single Solid Food Items Consumed by North Carolina Adults

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    Few studies have measured pyrethroid residue concentrations in food items consumed by adults in their daily environments. In a further analysis of study data, the objectives were to determine pyrethroid residue levels in single, solid food items consumed by adults and to estimate dietary pyrethroid exposures and intake doses per food item. A total of 50 adults collected 782 duplicate-diet solid food samples over a six-week monitoring period in North Carolina between 2009 and 2011. Of these samples, 188 contained a single, solid food item (i.e., lasagna). Levels of eight pyrethroids were quantified in the 188 food items using LC–MS/MS. At least one pyrethroid was detected in 39% of these food items. Cis-permethrin (17%), bifenthrin (15%), trans-permethrin (14%), and deltamethrin (14%) were detected the most often. Cyfluthrin, cyhalothrin, cypermethrin, and esfenvalerate were all detected in <6% of the samples. The highest residue level was found in a pizza sample containing both cis-permethrin (96.4 ng/g) and trans-permethrin (73.7 ng/g). For cis-permethrin, median residue levels (≥LOQ) were significantly higher (p = 0.001) in foods that contained a fruit/vegetable compared to foods that did not. For individual pyrethroids, the participants’ maximum dietary intake doses in the single food items ranged from 38.1 (deltamethrin) to 939 ng/kg/day (cis/trans-permethrin)

    Dietary Exposures and Intake Doses to Bisphenol A and Triclosan in 188 Duplicate-Single Solid Food Items Consumed by US Adults

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    Few data exist on bisphenol A (BPA) or triclosan (TCS) residue levels in foods consumed by adults in everyday settings. In a further analysis of study data, the objectives were to determine BPA and TCS residue concentrations in duplicate-single solid food items consumed by adults and to estimate dietary exposure and intake doses per food item. A convenience sample of 50 adults was recruited in North Carolina (2009–2011). Participants completed 24 h food diaries and collected 24 h duplicate-diet solid food samples consumed on days 1 and 2 during sampling weeks 1, 2, and 6. A total of 188 of the collected 776 duplicate-diet solid food samples contained a single, solid food item. BPA and TCS residue levels were quantified in the 188 food items using GC–MS. BPA and TCS were detected in 37% and 58% of these food items, respectively. BPA concentrations were highest in a cheese and tomato sandwich (104 ng/g), whereas the highest TCS concentrations were in a burrito (22.1 ng/g). These chemicals co-occurred in 20% of the samples (maximum = 54.7 ng/g). Maximum dietary intake doses were 429 ng/kg/day for BPA in a vegetable soup with tortilla sample and 72.0 ng/kg/day for TCS in a burrito sample

    Exposure to Triclosan and Bisphenol Analogues B, F, P, S and Z in Repeated Duplicate-Diet Solid Food Samples of Adults

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    Triclosan (TCS) and bisphenol analogues are used in a variety of consumer goods. Few data exist on the temporal exposures of adults to these phenolic compounds in their everyday diets. The objectives were to determine the levels of TCS and five bisphenol analogues (BPB, BPF, BPP, BPS, and BPZ) in duplicate-diet solid food (DDSF) samples of adults and to estimate maximum dietary exposures and intake doses per phenol. Fifty adults collected 776 DDSF samples over a six-week monitoring period in North Carolina in 2009–2011. The levels of the target phenols were concurrently quantified in the DDSF samples using gas chromatography/mass spectrometry. TCS (59%), BPS (32%), and BPZ (28%) were most often detected in the samples. BPB, BPF, and BPP were all detected in <16% of the samples. In addition, 82% of the total samples contained at least one target phenol. The highest measured concentration of 394 ng/g occurred for TCS in the food samples. The adults’ maximum 24-h dietary intake doses per phenol ranged from 17.5 ng/kg/day (BPB) to 1600 ng/kg/day (TCS). An oral reference dose (300,000 ng/kg/day) is currently available for only TCS, and the adult’s maximum dietary intake dose was well below a level of concern

    Exposure to Triclosan and Bisphenol Analogues B, F, P, S and Z in Repeated Duplicate-Diet Solid Food Samples of Adults

    No full text
    Triclosan (TCS) and bisphenol analogues are used in a variety of consumer goods. Few data exist on the temporal exposures of adults to these phenolic compounds in their everyday diets. The objectives were to determine the levels of TCS and five bisphenol analogues (BPB, BPF, BPP, BPS, and BPZ) in duplicate-diet solid food (DDSF) samples of adults and to estimate maximum dietary exposures and intake doses per phenol. Fifty adults collected 776 DDSF samples over a six-week monitoring period in North Carolina in 2009–2011. The levels of the target phenols were concurrently quantified in the DDSF samples using gas chromatography/mass spectrometry. TCS (59%), BPS (32%), and BPZ (28%) were most often detected in the samples. BPB, BPF, and BPP were all detected in <16% of the samples. In addition, 82% of the total samples contained at least one target phenol. The highest measured concentration of 394 ng/g occurred for TCS in the food samples. The adults’ maximum 24-h dietary intake doses per phenol ranged from 17.5 ng/kg/day (BPB) to 1600 ng/kg/day (TCS). An oral reference dose (300,000 ng/kg/day) is currently available for only TCS, and the adult’s maximum dietary intake dose was well below a level of concern
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