Environmental health perspectives
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Environ. Health Perspect. · Dec 2019
Acute Methylmercury Exposure and the Hypoxia-Inducible Factor- 1 α Signaling Pathway under Normoxic Conditions in the Rat Brain and Astrocytes in Vitro.
As a ubiquitous environmental pollutant, methylmercury (MeHg) induces toxic effects in the nervous system, one of its main targets. However, the exact mechanisms of its neurotoxicity have not been fully elucidated. Hypoxia-inducible factor- 1 α ( HIF- 1 α ), a transcription factor, plays a crucial role in adaptive and cytoprotective responses in cells and is involved in cell survival, proliferation, apoptosis, inflammation, angiogenesis, glucose metabolism, erythropoiesis, and other physiological activities. ⋯ MeHg induced a significant reduction in HIF- 1 α protein by activating proline hydroxylase (PHD) and the ubiquitin proteasome system (UPS) in primary rat astrocytes. Additionally, ROS scavenging by antioxidants played a neuroprotective role via increasing HIF- 1 α expression in response to MeHg toxicity. Moreover, we established that up-regulation of HIF- 1 α might serve to mitigate the acute toxicity of MeHg in astrocytes, affording a novel therapeutic target for future exploration. https://doi.org/10.1289/EHP5139.
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Environ. Health Perspect. · Oct 2019
Examining the Shape of the Association between Low Levels of Fine Particulate Matter and Mortality across Three Cycles of the Canadian Census Health and Environment Cohort.
Ambient fine particulate air pollution with aerodynamic diameter ≤2.5 μm (PM2.5) is an important contributor to the global burden of disease. Information on the shape of the concentration-response relationship at low concentrations is critical for estimating this burden, setting air quality standards, and in benefits assessments. ⋯ In a very large population-based cohort with up to 25 y of follow-up, PM2.5 was associated with nonaccidental mortality at concentrations as low as 5 μg/m3. https://doi.org/10.1289/EHP5204.
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Environ. Health Perspect. · Apr 2019
Associations between Maternal Tobacco Smoke Exposure and the Cord Blood [Formula: see text] DNA Methylome.
Maternal tobacco smoke exposure has been associated with altered DNA methylation. However, previous studies largely used methylation arrays, which cover a small fraction of CpGs, and focused on whole cord blood. ⋯ Maternal tobacco smoke exposure in pregnancy is associated with cord blood [Formula: see text] DNA methylation in key regulatory regions, including enhancers. While we used a method that performs well on low-coverage data, we cannot exclude the possibility that some results may be false positives. However, we identified a differentially methylated CpG in amino acid transporter SLC7A8 that is highly reproducible, which may be sensitive to cigarette smoke in both cord blood and adult [Formula: see text] cells. https://doi.org/10.1289/EHP3398.
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Environ. Health Perspect. · Jan 2019
Geographic, Demographic, and Temporal Variations in the Association between Heat Exposure and Hospitalization in Brazil: A Nationwide Study between 2000 and 2015.
Limited evidence is available regarding the association between heat exposure and morbidity in Brazil and how the effect of heat exposure on health outcomes may change over time. ⋯ In Brazil's hot seasons, 6% of hospitalizations were estimated to be attributed to heat exposure. As there was no evidence indicating that thermal adaptation had occurred at the national level, the burden of hospitalization associated with heat exposure in Brazil is likely to increase in the context of global warming. https://doi.org/10.1289/EHP3889.
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Environ. Health Perspect. · Sep 2018
Association of Prenatal Urinary Concentrations of Phthalates and Bisphenol A and Pubertal Timing in Boys and Girls.
Animal studies suggest that phthalates and bisphenol A (BPA), endocrine-disrupting chemicals found in many consumer products, may impact the timing of puberty. ⋯ Several high-molecular-weight phthalates and BPA were associated with later puberty in girls and earlier puberty in boys included in the CHAMACOS cohort study. Childhood overweight/obesity may modify these associations. https://doi.org/10.1289/EHP3424.