Concentrations of bisphenol A (BPA) in North American and European fresh and marine surface waters and sediments were analyzed to quantify environmental levels and evaluate trends over the years 1996-2014. In North American surface water and sediment, 68% of 1030 weighted observations were below a detection limit (varied widely between studies). In Europe, 33% of 5057 weighted observations were below a detection limit. In North America and Europe, 50th percentile concentrations were 0.005 μg L-1 and 0.029 μg L-1 in freshwater and 0.0011 μg L-1 and 0.007 μg L-1 in marine water. The 95th percentile concentrations in freshwater were the same in North America and Europe at 0.30 μg L-1 and were 0.024 μg L-1 and 0.15 μg L-1 in marine water, respectively. Fiftieth percentile concentrations in North American and European freshwater sediment were 0.7 ng g-1 dry weight (dw) and 7.0 ng g-1 dw and in marine sediment were 1.0 ng g-1 dw and <0.03 ng g-1 dw, respectively. The 95th percentile concentrations were 39 ng g-1 dw and 177 ng g-1 dw in freshwater sediment and 100 ng g-1 dw and 63 ng g-1 dw in marine sediment, respectively. Most concentrations were below published chronic toxicity values or regulatory limits. BPA freshwater concentrations in both regions appear to have remain relatively unchanged over the 19 year period during which BPA production and use in polycarbonate plastic production increased significantly. There is no clear correlation between BPA or polycarbonate production and BPA levels in surface waters.
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http://dx.doi.org/10.1016/j.chemosphere.2018.02.175 | DOI Listing |
BMC Public Health
January 2025
Faculty of Social Work, University of Toronto, 246 Bloor St W, Toronto, ON, M5S 1V4, Canada.
Background: Loneliness is a public health epidemic in the United States (US), with older adults being vulnerable to experiencing loneliness. Predictors of loneliness are less understood among racial/ethnic groups of US older adults, and few studies have included perceived institutional discrimination (PID), stressful life events (SLE), and perceived neighborhood characteristics (PNC) as antecedent stressors of loneliness in diverse older adult samples. Our study assessed the relationship between these stressors and loneliness among specific racial/ethnic groups of older adults.
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January 2025
University of Minnesota Medical School, 420 Delaware Street SE, Mayo Building, Minneapolis, MN, 55455, USA.
Background: A common practice in assessment development, fundamental for fairness and consequently the validity of test score interpretations and uses, is to ascertain whether test items function equally across test-taker groups. Accordingly, we conducted differential item functioning (DIF) analysis, a psychometric procedure for detecting potential item bias, for three preclinical medical school foundational courses based on students' sex and race.
Methods: The sample included 520, 519, and 344 medical students for anatomy, histology, and physiology, respectively, collected from 2018 to 2020.
Nature
January 2025
School of Life Sciences, Hebei University, Baoding, China.
Extreme droughts generally decrease productivity in grassland ecosystems with negative consequences for nature's contribution to people. The extent to which this negative effect varies among grassland types and over time in response to multi-year extreme drought remains unclear. Here, using a coordinated distributed experiment that simulated four years of growing-season drought (around 66% rainfall reduction), we compared drought sensitivity within and among six representative grasslands spanning broad precipitation gradients in each of Eurasia and North America-two of the Northern Hemisphere's largest grass-dominated regions.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Biomedical Engineering, Duke University, Durham, NC, USA.
Acoustically probing biological tissues with light or sound, photoacoustic and ultrasound imaging can provide anatomical, functional, and/or molecular information at depths far beyond the optical diffusion limit. However, most photoacoustic and ultrasound imaging systems rely on linear-array transducers with elevational focusing and are limited to two-dimensional imaging with anisotropic resolutions. Here, we present three-dimensional diffractive acoustic tomography (3D-DAT), which uses an off-the-shelf linear-array transducer with single-slit acoustic diffraction.
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