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النتائج 991 - 1000 من 6,548
Long-term exposure to outdoor and household air pollution and blood pressure in the Prospective Urban and Rural Epidemiological (PURE) study النص الكامل
2020
Arku, Raphael E. | Bräuer, Michael | Ahmed, Suad H. | AlHabib, Khalid F. | Avezum, Alvaro | Bo, Jian | Choudhury, Tarzia | Dans, Antonio ML. | Gupta, Rajiv | Iqbal, Romaina | Ismail, Noorhassim | Kelishadi, Roya | Khatib, Rasha | Koon, Teo | Kumar, Rajesh | Lanas, Fernando | Lear, Scott A. | Wei, Li | Lopez-Jaramillo, Patricio | Mohan, Viswanathan | Poirier, Paul | Puoane, Thandi | Rangarajan, Sumathy | Rosengren, Annika | Soman, Biju | Caklili, Ozge Telci | Yang, Shunyun | Yeates, Karen | Yin, Lu | Yusoff, Khalid | Zatoński, Tomasz | Yūsuf, Sālim | Hystad, Perry
Exposure to air pollution has been linked to elevated blood pressure (BP) and hypertension, but most research has focused on short-term (hours, days, or months) exposures at relatively low concentrations. We examined the associations between long-term (3-year average) concentrations of outdoor PM₂.₅ and household air pollution (HAP) from cooking with solid fuels with BP and hypertension in the Prospective Urban and Rural Epidemiology (PURE) study. Outdoor PM₂.₅ exposures were estimated at year of enrollment for 137,809 adults aged 35–70 years from 640 urban and rural communities in 21 countries using satellite and ground-based methods. Primary use of solid fuel for cooking was used as an indicator of HAP exposure, with analyses restricted to rural participants (n = 43,313) in 27 study centers in 10 countries. BP was measured following a standardized procedure and associations with air pollution examined with mixed-effect regression models, after adjustment for a comprehensive set of potential confounding factors. Baseline outdoor PM₂.₅ exposure ranged from 3 to 97 μg/m³ across study communities and was associated with an increased odds ratio (OR) of 1.04 (95% CI: 1.01, 1.07) for hypertension, per 10 μg/m³ increase in concentration. This association demonstrated non-linearity and was strongest for the fourth (PM₂.₅ > 62 μg/m³) compared to the first (PM₂.₅ < 14 μg/m³) quartiles (OR = 1.36, 95% CI: 1.10, 1.69). Similar non-linear patterns were observed for systolic BP (β = 2.15 mmHg, 95% CI: −0.59, 4.89) and diastolic BP (β = 1.35, 95% CI: −0.20, 2.89), while there was no overall increase in ORs across the full exposure distribution. Individuals who used solid fuels for cooking had lower BP measures compared to clean fuel users (e.g. 34% of solid fuels users compared to 42% of clean fuel users had hypertension), and even in fully adjusted models had slightly decreased odds of hypertension (OR = 0.93; 95% CI: 0.88, 0.99) and reductions in systolic (−0.51 mmHg; 95% CI: −0.99, −0.03) and diastolic (−0.46 mmHg; 95% CI: −0.75, −0.18) BP. In this large international multi-center study, chronic exposures to outdoor PM₂.₅ was associated with increased BP and hypertension while there were small inverse associations with HAP.
اظهر المزيد [+] اقل [-]Monitoring of microplastics in the clam Donax cuneatus and its habitat in Tuticorin coast of Gulf of Mannar (GoM), India النص الكامل
2020
Narmatha Sathish, M. | Immaculate Jeyasanta, K. | Patterson, Jamila
Microplastics (MPs) in the marine environment are ubiquitous. The ingestion of these pollutants by marine organisms has drawn global attention. This work studies the distribution pattern and characteristics of MPs found in the body of the clam Donax cuneatus and its environment in order to understand the possible relationship between the MP concentration in the environment (water and sediment) and that in the clam’s body. Samples of D. cuneatus were collected from the coast between Vembar and Periyathazhai in Tuticorin district along GoM. MP concentrations range from 0.6 to 1.3 items/g (wet weight) in clams, 10–30 items/l in water, and 24–235 items/kg in sediment. Small-sized clams contain the highest concentration of MPs. Hence it is hypothesised that allometric relationship exists between body size and MP concentration, depending on the surface-area to volume ratio. MP abundance in clam body has a clear, positive, significant correlation with MP abundance in sediment but not with abundance of MP in water. Microplastics of fiber type with size 100–250 μm have a predominant presence in clams. The study identified ten types of polymers, of which polyethylene is the most common polymer in all sample types. FTIR-ATR spectra and surface morphology indicate that most of the microplastics have been strongly weathered. Energy dispersive X-ray spectroscopy analysis detected heavy metals associated with MPs like Cd, Pb, Cu, Zn, Ni and Fe. Filter-feeding clams like Donax sp. can provide valuable information on the spatial patterns of MP distribution, and so can act as bio-indicators in monitoring MP pollution in coastal areas.
اظهر المزيد [+] اقل [-]Spatiotemporal variability, source apportionment, and acid-neutralizing capacity of atmospheric wet base-cation deposition in China النص الكامل
2020
Zhang, Qiongyu | Wang, Qiufeng | Zhu, Jianxing | Xu, Li | Chen, Zhi | Xiao, Jingfeng | He, Nianpeng
Atmospheric wet deposition of base cations (BCs) plays a significant role in providing plant nutrients and buffering acidification. However, the temporal dynamic of wet BC deposition in China during the past two decades remain unclear. Here, we used long-term monitoring and literature data since 2000 to assess the temporal dynamics (seasonal and inter-annual variation), spatial patterns, main influencing factors, source apportionment, and capacity to neutralize the acidity of wet BC depositions at site, regional, and national scales. The results showed that total wet deposition of BCs was, on average, 2.12 keq ha⁻¹ yr⁻¹, where Ca²⁺ accounted for 65.57% of the total deposition, followed by Na⁺ (13.21%), Mg²⁺ (13.68%), and K⁺ (7.55%). Qinghai-Tibet had significantly lower BC deposition fluxes than northern, southern, and central China, as well as Inner Mongolia. Exchangeable BCs in soil, PM₁₀ in the atmosphere, energy consumption, and cement production are significantly related to wet BC deposition, which account for 79.17% of the variation in the spatial deposition of BC. Influenced by the strategies to control acid rain and particulate matter in China, interannual variations showed a stabilization trend after a continuous decline from 2000 to 2017, which can be explained by inter-annual changes in PM₁₀, energy consumption and cement production. Statistical methods confirmed that 45.95% of wet BC deposition was derived from crustal contributions, 27.78% from sea salt sources, and 26.27% from anthropogenic sources. Furthermore, we found that wet deposition of BCs neutralized 84.85% of the acidity due to NO₃⁻ and SO₄²⁻ depositions. Under the emissions reduction strategy, there has been a decrease in the deposition of BC. However, SO₄²⁻ and NO₃⁻ depositions decreased faster than BC deposition, which buffered a higher proportion of acidic depositions. Our findings contribute to an improved understanding of wet BC deposition in China, an evaluation of their capacity to neutralize acidity, and important parameters for acidification models.
اظهر المزيد [+] اقل [-]Exposure to etoxazole induces mitochondria-mediated apoptosis in porcine trophectoderm and uterine luminal epithelial cells النص الكامل
2020
Park, Wonhyoung | Lim, Whasun | Park, Sunwoo | Whang, Kwang-Youn | Song, Gwonhwa
Etoxazole is an organofluorine insecticide widely used in agriculture. Exposure to insecticides is a serious environmental problem owing to their cytotoxic effects in humans and animals. Reproductive toxicity of various organofluorine insecticides have been shown in previous studies. However, few studies have evaluated the toxicity of etoxazole in mammals. We aimed to examine the toxic effects of etoxazole in porcine trophectoderm (pTr) and uterine luminal epithelial (pLE) cells. To estimate the effects of etoxazole, we conducted assays after treatment with multiple concentration of etoxazole (0, 2, 4, 6 and 9 μM) to pTr and pLE cells for 0–72 h. Etoxazole decreased the cell proliferation, viability, and migration of pTr and pLE cells. Further, etoxazole induced apoptosis via cell cycle arrest and disruption of mitochondrial membrane potential. We also found that pro-apoptotic proteins and endoplasmic reticulum (ER) stress-response proteins were activated in response to etoxazole. Finally, we observed that etoxazole altered the PI3K/AKT and MAPK signaling pathways and the mRNA expression of genes associated with implantation. Collectively, these results suggest that etoxazole disrupts normal cellular physiology and might cause early implantation failure.
اظهر المزيد [+] اقل [-]Experimental and theoretical insights into kinetics and mechanisms of hydroxyl and sulfate radicals-mediated degradation of sulfamethoxazole: Similarities and differences النص الكامل
2020
Gao, Lingwei | Mao, Qiming | Luo, Shuang | Cao, Linying | Xie, Xiande | Yang, Yuan | Deng, Yunfeng | Wei, Zongsu
Hydroxyl radical (•OH)- and sulfate radical (▪)-based advanced oxidation technologies (AOTs) have been proven an effective method to remove antibiotics in wastewater treatment plants (WWTPs). This study aims to gain insights into kinetics and mechanisms of neutral sulfamethoxazole (SMX) degradation, a representative antibiotic, by •OH and ▪ using an experimental and theoretical approach. First, the second-order rate constants (k) of SMX with •OH and ▪ were determined to be (7.27 ± 0.43) × 10⁹ and (2.98 ± 0.32) × 10⁹ M⁻¹ s⁻¹ in UV/H₂O₂ and UV/persulfate (UV/PS) systems, respectively. The following theoretical calculations at the M06–2X level of theory revealed that addition of radicals to the benzene ring is the most favorable first-step reaction for both •OH and ▪, but that ▪ exhibits higher energy barriers and selectivity than •OH due to steric hindrance. We further analyzed subsequent reactions and, interestingly, our findings closely corroborated HOMO/LUMO distributions of SMX to the oxidation pathways. Finally, the estimation of energy consumption for UV alone, •OH–, and ▪–mediated oxidation processes was compared. These comparative results, for the first time, provide insights into the similarities and differences of degradation of SMX by •OH/▪ at the molecular level and can help improve antibiotics removal using radical based AOTs in WWTPs.
اظهر المزيد [+] اقل [-]Usefulness of bee bread and capped brood for the assessment of monocyclic aromatic hydrocarbon levels in the environment النص الكامل
2020
Zięba, Katarzyna | Szostak, Elżbieta | Czekońska, Krystyna | Miśkowiec, Paweł | Moos-Matysik, Agnieszka | Nyczyk-Malinowska, Anna | Szentgyörgyi, Hajnalka
Usefulness of bee bread and capped brood for the assessment of monocyclic aromatic hydrocarbon levels in the environment النص الكامل
2020
Zięba, Katarzyna | Szostak, Elżbieta | Czekońska, Krystyna | Miśkowiec, Paweł | Moos-Matysik, Agnieszka | Nyczyk-Malinowska, Anna | Szentgyörgyi, Hajnalka
Monitoring airborne pollutants, like aromatic hydrocarbons, are raising more and more concerns recently. Various sampling techniques and methods are known to collect, measure, and analyse environmental pollution levels based on honey bee bodies or bee product samples. Although honey bees are studied in detail and sampling methods are becoming more and more sophisticated biological samples may significantly differ in pollutant accumulation, showing a wide range of pollution levels even in the same site and environment. We have compared the pollution levels of honey bee capped brood and bee bread (pollen collected by honey bees and deposited in the hive) originating from four sites during two years of study and twelve honey bee families near various pollution sources emitting monocyclic aromatic hydrocarbons (BTEX) to the environment. Our result showed, that the environmental monitoring of BTEX can be based on sampling honey bees, and bee bread in particular. However, we found a significant difference in the uptake of these pollutants regarding sample type. Pollen collected as a food source revealed consistently higher levels of BTEX than bee brood, as well as some other differences in pollution levels between samples and between seasons, as opposed to capped brood. Based on our results, we suggest that for measuring and monitoring of BTEX pollution in the environment the use of bee bread is a valuable source of information.
اظهر المزيد [+] اقل [-]Usefulness of bee bread and capped brood for the assessment of monocyclic aromatic hydrocarbon levels in the environment النص الكامل
Katarzyna Zięba | Elżbieta Szostak | Krystyna Czekońska | Paweł Miśkowiec | Agnieszka Moos-Matysik | Anna Nyczyk-Malinowska | Hajnalka Szentgyörgyi
Monitoring airborne pollutants, like aromatic hydrocarbons, are raising more and more concerns recently. Various sampling techniques and methods are known to collect, measure, and analyse environmental pollution levels based on honey bee bodies or bee product samples. Although honey bees are studied in detail and sampling methods are becoming more and more sophisticated biological samples may significantly differ in pollutant accumulation, showing a wide range of pollution levels even in the same site and environment. We have compared the pollution levels of honey bee capped brood and bee bread (pollen collected by honey bees and deposited in the hive) originating from four sites during two years of study and twelve honey bee families near various pollution sources emitting monocyclic aromatic hydrocarbons (BTEX) to the environment. Our result showed, that the environmental monitoring of BTEX can be based on sampling honey bees, and bee bread in particular. However, we found a significant difference in the uptake of these pollutants regarding sample type. Pollen collected as a food source revealed consistently higher levels of BTEX than bee brood, as well as some other differences in pollution levels between samples and between seasons, as opposed to capped brood. Based on our results, we suggest that for measuring and monitoring of BTEX pollution in the environment the use of bee bread is a valuable source of information. | 100 | 2-10 | Part A
اظهر المزيد [+] اقل [-]Deterministic and probabilistic health risk assessment techniques to evaluate non-carcinogenic human health risk (NHHR) due to fluoride and nitrate in groundwater of Panipat, Haryana, India النص الكامل
2020
Kaur, Lakhvinder | Rishi, Madhuri S. | Siddiqui, Azeem Uddin
Human interferences have caused groundwater contamination in alluvial aquifers which subsequently affects the health of exposed population. In the present study, 74 groundwater samples from the semi-arid region of Panipat district, falling under Yamuna sub-basin, India was evaluated to know the potential non-carcinogenic human health risk in local adult and child population. The major objective of the present study was to know the non-carcinogenic human health risk due to intake of fluoride and nitrate contaminated water, using two different approaches: deterministic and probabilistic (Monte Carlo simulation). The values of hazard quotient (HQ) determined by deterministic as well as probabilistic approach were nearly identical. The hazard index (HI) value of 40.8% samples was above the unity in case of adults while 69.7% samples indicated HI value greater than unity for children thus indicating children are more prone to non-carcinogenic health risk than the adult population. Sensitivity analysis was performed to identify the influence of the non-carcinogenic human health risk predictor variables for the prediction of risk and concentration factor (CF) was the most influential variable. Multivariate statistical techniques were employed to know the positive and negative relationship of fluoride and nitrate with other parameters. Results of principal component analysis/factor analysis (PCA/FA) indicated that the concentration of fluoride is controlled by the presence of calcium due to their negative correlation in groundwater samples. The hierarchical agglomerative cluster analysis (HCA) also supported the outcome of PCA/FA and both indicated anthropogenic sources of fluoride and nitrate in groundwater.
اظهر المزيد [+] اقل [-]Dibutyl phthalate contamination accelerates the uptake and metabolism of sugars by microbes in black soil النص الكامل
2020
Chen, Wenjing | Wang, Zhigang | Xu, Weihui | Tian, Renmao | Zeng, Jin
Dibutyl phthalate (DBP) is widely used as plasticizer and has been detected in the environment, posing a threat to animal health. However, the effects of DBP on agricultural microbiomes are not known. In this study, DBP levels in black soil were evaluated, and the impact of DBP contamination on the uptake and metabolism of sugars in microbes was assessed by glucose absorption tests, metaproteomics, metabolomics, enzyme activity assays and computational simulation analysis. The results indicated that DBP contamination accelerated glucose consumption and upregulated the expression of porins and periplasmic monosaccharide ATP-binding cassette (ABC) transporter solute-binding proteins (SBPs). DBP and its metabolic intermediates (carboxymuconate and butanol) may form a stable complex with sugar transporters and enhance the rigidity and stability of these proteins. Sugar metabolism resulting in the generation of ATP and reducing agent (NADPH), as well as the expression of some key enzymes (dehydrogenases) were also upregulated by DBP treatment. Moreover, a diverse bacterial community appears to utilize sugar, suggesting that there are widespread effects of DBP contamination on soil microbial ecosystems. The results of this study provide a theoretical basis for investigating the toxicological effects of DBP on microbes in black soil.
اظهر المزيد [+] اقل [-]Impact of mariculture-derived microplastics on bacterial biofilm formation and their potential threat to mariculture: A case in situ study on the Sungo Bay, China النص الكامل
2020
Sun, Xuemei | Chen, Bijuan | Xia, Bin | Li, Qiufen | Zhu, Lin | Zhao, Xinguo | Gao, Yaping | Qu, Keming
Microplastics (MPs) pollution in the marine environment has attracted considerable global attention. However, the colonization of microorganisms on mariculture-derived MPs and their effects on mariculture remain poorly understood. In this study, the MPs (fishing nets, foams and floats) and a natural substrate, within size ranges (1–4 mm), were then incubated for 21 days in Sungo Bay (China), and the composition and diversity of bacterial communities attached on all substrates were investigated. Results showed that bacterial communities on MPs mainly originated from their surrounding seawater and sediment, with an average contribution on total MPs adherent population of 47.91% and 37.33%, respectively. Principle coordinate analysis showed that community similarity between MPs and surrounding seawater decreased with exposure time. In addition, lower average bacterial community diversity and higher relative abundances of bacteria from the genera Vibrio, Pseudoalteromonas and Alteromonas on MPs than those in their surrounding seawater and sediments indicated that MPs might enrich potential pathogens and bacteria related with carbohydrate metabolism. They are responsible for the significant differences in KEGG Orthology pathways (infectious disease and carbohydrate metabolism) between MPs and seawater. The KO pathway (Infectious Diseases) associated with MPs was also significantly higher than those with feathers in the nearshore area. MPs might be vectors for enrichment of potentially pathogenic Vibrio, and enhance the ecological risk of MPs to mariculture industry.
اظهر المزيد [+] اقل [-]Household air pollution and personal exposure from burning firewood and yak dung in summer in the eastern Tibetan Plateau النص الكامل
2020
Ye, Wenlu | Saikawa, Eri | Avramov, Alexander | Cho, Seung-Hyun | Chartier, Ryan
This study assessed the sources, magnitudes, and chemical compositions of household air pollution (HAP) and personal exposure in traditional Tibetan households. We measured 24-h personal exposures to PM₂.₅ and kitchen area black carbon (BC) concentrations, using MicroPEMs and microAeths, respectively. Particulate polycyclic aromatic hydrocarbon (PAH) and inorganic element concentrations were quantified via post analyses of a subset of MicroPEM sample filters. Household surveys regarding participant demographics, cookstove usage, household fuel, cooking behaviors, and lifestyles were collected. The results reaffirm that burning firewood and yak dung, mainly for cooking, leads to high PM₂.₅ and BC exposures. The geometric mean concentration (95% confidence interval, CI) was 74.3 (53.6, 103) μg/m³ for PM₂.₅ and the arithmetic mean ± standard deviation (SD) concentration was 4.90 ± 5.01 μg/m³ for BC and 292 ± 364 ng/m³ for 15 identified PAHs, respectively. The arithmetic mean ± SD of mass concentrations of 24 detected elements ranged from 0.76 ± 0.91 ng/m³ (Co) to 1.31 ± 1.35 μg/m³ (Si). Our statistical analyses further illustrated that the high concentrations of PM₂.₅, BC, and most PAHs and metals, are significantly associated with nomadic village, poorer stove/chimney conditions and yak dung burning. The results from this study show that substantial HAP exposure is prevalent in Tibetan households and requires immediate actions to mitigate potential negative environmental health impacts. The observational data also revealed the possibility of other important sources (e.g. traffic and garbage burning) that have contributed to personal exposures. These findings improve our understanding of HAP exposure and potential health risks in Tibetan communities and will help inform strategies for reducing HAP in Tibetan households and beyond.
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