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Exposure of U.S. population to endocrine disruptive chemicals (Parabens, Benzophenone-3, Bisphenol-A and Triclosan) and their associations with female infertility Full text
2020
Arya, Sushila | Dwivedi, Alok Kumar | Alvarado, Luis | Kupesic-Plavsic, Sanja
Ubiquitous exposure to endocrine disruptive chemicals (EDC) among women of reproductive age is alarming. Exposure to EDCs could be contributing to infertility. We determined the association between common EDCs and self-reported infertility among U.S. women, 18–45 years of age using the National Health and Nutrition Examination Surveys (NHANES) for periods 2013–2014 and 2015–2016. A cross-sectional study on reproductive age women was conducted. Available important sociodemographic variables, and urinary concentrations of parabens (methyl paraben [MP], ethyl paraben [EP], propyl paraben [PP], and butyl paraben [BP]), Benzophenone-3 (BP-3), Bisphenol-A (BPA), and triclosan (TCS) were obtained from the NHANES databases. Clustering among EDCs were obtained using variable cluster analysis. Relative risk regression models were used to estimate associations of individual and combined EDCs with self-reported infertility after applying appropriate survey weights to account for the complex survey design as well as to compensate for the four-year cycle. Results were summarized using prevalence ratio (PR) with 95% confidence interval (CI). Of total 789 individuals included in the study, 14% (95%CI: 11%–18%) had infertility. MP and PP were detected in 99% of urine samples, BP in 46%, EP and BP-3 in 96%, BPA in 94% and TCS in 73%. Self-reported infertility was significantly associated with combined score of BP-3, BPA and TCS (PR = 1.13, p = 0.007), and above detection level of EP (PR = 1.57, p = 0.025) even after adjusting for potential confounders. Our results suggested the EP and mixtures of benzophenones, TCS, and BPA were associated with infertility among the U.S. women. However, because of the limitations inherent to the cross-sectional study design, prospective cohort studies are warranted to confirm these findings.
Show more [+] Less [-]Atmospheric boundary layer turbulence structure for severe foggy haze episodes in north China in December 2016 Full text
2020
Li, Xin | Gao, Chloe Y. | Gao, Zhiqiu | Zhang, Xiaoye
This paper aims to identify the atmospheric boundary layer turbulence structure and its effect on severe foggy haze events frequently occurring in Northern China. We use data collected from a ground eddy covariance system, meteorology tower, and a PM₂.₅ collector in Baoding, China during December 2016. The data shows that 73.5% of PM₂.₅ concentration is greater than 100 μg m⁻³ with a maximum of 522 μg m⁻³. Analyses on vertical turbulence spectrum also reveal that 1) during the pollution period, lower wind can suppress large-scale turbulence eddies, which are more likely inhomogeneous, breaking into small-scale eddies, and 2) the air pollutant scattering effect for radiation could decrease the air temperature near the ground and generate weak vertical turbulence during the daytime. At night, air pollutants suppress the land surface cooling and decrease the air temperature difference as well as the vertical turbulence intensity difference. The vertical turbulence impact analysis reveals that the percentage of large-scale turbulence eddies can also change the atmospheric vertical mixing capacity. During the daytime, the air pollution evolution is controlled by the wind speed and vertical turbulence intensity. While at night, the vertical turbulence is weak and the atmospheric vertical mixing capacity is mainly controlled by the large-scale eddies’ percentage. The increased number of large-scale turbulence eddies led by low wind at night could increase the vertical mixing of air pollutants and decrease its concentration near the ground.
Show more [+] Less [-]Effects of long-term exposure to microfibers on ecosystem services provided by coastal mussels Full text
2020
Christoforou, Eleni | Dominoni, Davide M. | Lindström, Jan | Stilo, Giulia | Spatharis, Sofie
The biofiltration capacity of bivalve populations is known to alleviate the effects of coastal eutrophication. However, this important ecosystem service could potentially be impaired by the increasing microplastic abundance in near shore environments. It is known that relatively large microplastics (∼500 μm) impair the filtration capacity of bivalves. However, the effect of smaller microplastics, and specifically microfibers, is not known even though they are more common in many natural systems and similar in size to phytoplankton, the main food source of mussels. Here, we investigated the effects of long-term exposure to microfibers (MFs), which are smaller than 100 μm, on the biofiltration capacity of the blue mussel, Mytilus edulis. Our findings show that long-term exposure (here 39 days) to microfibers significantly reduced (21%) the clearance of phytoplankton (Tetraselmis sp). While previous studies have shown that larger microplastics can decrease the filtration capacity of mussels after short-term exposure, our findings suggest that, for smaller MFs, mussel’s clearance capacity is significantly affected after long-term exposure (39 days in this study). This may be due to the accumulation of MFs in the digestive system. In addition, the most efficient phytoplankton consumers were more susceptible to MF accumulation in the digestive system. This suggests that prolonged exposure to MF of coastal mussels could negatively impact the biofiltration of more potent individuals, thus decreasing the ecosystem service potential of the population as a whole.
Show more [+] Less [-]Acrolein-induced apoptosis of smooth muscle cells through NEAT1-Bmal1/Clock pathway and a protection from asparagus extract Full text
2020
Chen, Lijun | Wu, Xiaoyue | Zeb, Falak | Huang, Yunxiang | An, Jing | Jiang, Pan | Chen, Aochang | Xu, Chuyue | Feng, Qing
Apoptosis of vascular smooth muscle cells (VSMCs) accelerates manifestation of plaque vulnerability in atherosclerosis. Long noncoding RNA NEAT1 participates in the proliferation and apoptosis of cells. In addition, circadian clock genes play a significant role in cell apoptosis. However, whether acrolein, an environmental pollutant, affects the apoptosis of VSMCs by regulating NEAT1 and clock genes is still elusive. We established VSMCs as an atherosclerotic cell model in vitro. Acrolein exposure reduced survival rate of VSMCs, and raised apoptosis percentage through upregulating the expression of Bax, Cytochrome c and Cleaved caspase-3 and downregulating Bcl-2. Asparagus extract (AE), as a dietary supplementation, was able to protect VSMCs against acrolein-induced apoptosis. Expression of NEAT1, Bmal1 and Clock was decreased by acrolein, while was ameliorated by AE. Knockdown of NEAT1, Bmal1 or Clock promoted VSMCs apoptosis by regulating Bax, Bcl-2, Cytochrome c and Caspase-3 levels. Correspondingly, overexpression of NEAT1 inhibited the apoptosis. We also observed that silence of NEAT1 repressed the expression of Bmal1/Clock and vice versa. In this study, we demonstrated that VSMCs apoptosis induced by acrolein was associated with downregulation of NEAT1 and Bmal1/Clock. AE alleviated the effects of proapoptotic response and circadian disorders caused by acrolein, which shed a new light on cardiovascular protection.
Show more [+] Less [-]Swine slurry characteristics as affected by selected additives and disinfectants Full text
2020
Duerschner, Jon | Bartelt-Hunt, Shannon | Eskridge, Kent M. | Gilley, John E. | Li, Xu | Schmidt, Amy M. | Snow, Daniel D.
Current swine industry practice is to house animals in confinement facilities which capture and store feces and urine as slurry in pits below the production area. Additives and disinfectants may be introduced into the manure pits. This study was conducted to measure the effects of additives and disinfectants on temporal changes in swine slurry characteristics. Slurry from a commercial swine production facility in southeast Nebraska, USA was collected and transferred to 57 L reactors located within a greenhouse. Selected additives and disinfectants were added to the reactors and physical properties, chemical characteristics, and antibiotic concentrations were monitored for 40 days. Concentrations of dry matter (DM), total nitrogen (TN), phosphorus pentoxide (P₂O₅), calcium (Ca), magnesium (Mg), zinc (Zn), iron (Fe), manganese (Mn), and copper (Cu) were significantly greater than the Control in each of the reactors containing additives. The reactors in which the additives MOC-7, More Than Manure®, Sludge Away, and Sulfi-Doxx were introduced had significantly greater values of chemical oxygen demand (COD), total volatile solids (TVS), total suspended solids (TSS), total solids (TS), dry matter (DM), TN, P₂O₅, Ca, Mg, Zn, Fe, Mn, Cu and chlortetracycline than the other additive treatments. Concentrations of TVS and TSS were significantly lower in the reactors containing Clorox® and Virkon™ than the other disinfectant treatments. The total dissolved solids (TDS) concentration of 26,500 mg L⁻¹ and pH value of 7.27 obtained for the reactors containing Tek-Trol were significantly greater than measurements obtained for the other treatments. Concentrations of chlortetracycline and tiamulin of 8840 and 28.8 ng g⁻¹, respectively, were significantly lower for the treatments containing Tek-Trol. The sodium (Na) concentration of 1070 mg L⁻¹ measured in the reactors containing Clorox® was significantly greater than values for the other disinfectant treatments. The introduction of selected additives and disinfectants may influence certain physical properties, chemical characteristics, and antibiotic concentrations of swine slurry.
Show more [+] Less [-]MicroRNA-382-5p is involved in pulmonary inflammation induced by fine particulate matter exposure Full text
2020
Zhang, Xinwei | Zhang, Yanshu | Meng, Qingtao | Sun, Hao | Wu, Shenshen | Xu, Jie | Yun, Jun | Yang, Xi | Li, Bin | Zhu, Hao | Xue, Ling | Li, Xiaobo | Chen, Rui
Exposure to atmospheric particulate matter (PM) has been related to the increasing incidence and mortality of pulmonary diseases, where microRNAs (miRNAs) play significant roles in these biological and pathological processes. In the present study, we found that miR-382-5p played an anti-inflammatory role in pulmonary inflammation induced by fine particulate matter (PM₂.₅) or diesel exhaust particles (DEPs) in vitro and in vivo. The expression level of miR-382-5p was downregulated, while its target gene, namely CXCL12, was elevated in HBE cells after exposure to PM₂.₅ or DEPs. Mechanistically, PM₂.₅ or DEPs exposure increased CXCL12/MMP9 expression via miR-382-5p inhibition, subsequently triggered pulmonary inflammation. Furthermore, antagonizing the function of CXCL12 significantly reduced the expression of MMP9 and local inflammation induced by PM₂.₅ or DEPs. PM₂.₅ or DEPs caused apoptosis and G1 phase arrest could be partially restored by overexpression of miR-382-5p and antagonism of CXCL12. In a murine model, enhanced miR-382-5p expression effectively reduced expression levels of CXCL12, MMP9 and inflammatory cytokines, hereby protected lung tissues against PM₂.₅ or DEPs-induced lesions. Collectively, the miR-382-5p/CXCL12/MMP9 pathway may provide a mechanism, which mediates inflammatory response to PM₂.₅ or DEPs exposure.
Show more [+] Less [-]Effects of different mobile phone UMTS signals on DNA, apoptosis and oxidative stress in human lymphocytes Full text
2020
Gulati, Sachin | Kosik, Pavol | Durdik, Matus | Skorvaga, Milan | Jakl, Lukas | Markova, Eva | Belyaev, Igor
Different scientific reports suggested link between exposure to radiofrequency radiation (RF) from mobile communications and induction of reactive oxygen species (ROS) and DNA damage while other studies have not found such a link. However, the available studies are not directly comparable because they were performed at different parameters of exposure, including carrier frequency of RF signal, which was shown to be a critical for appearance of the RF effects. For the first time, we comparatively analyzed genotoxic effects of UMTS signals at different frequency channels used by 3G mobile phones (1923, 1947.47, and 1977 MHz). Genotoxicity was examined in human lymphocytes exposed to RF for 1 h and 3 h using complimentary endpoints such as induction of ROS by imaging flow cytometry, DNA damage by alkaline comet assay, mutations in TP53 gene by RSM assay, preleukemic fusion genes (PFG) by RT-qPCR, and apoptosis by flow cytometry. No effects of RF exposure on ROS, apoptosis, PFG, and mutations in TP53 gene were revealed regardless the UMTS frequency while inhibition of a bulk RNA expression was found. On the other hand, we found relatively small but statistically significant induction of DNA damage in dependence on UMTS frequency channel with maximal effect at 1977.0 MHz. Our data support a notion that each specific signal used in mobile communication should be tested in specially designed experiments to rule out that prolonged exposure to RF from mobile communication would induce genotoxic effects and affect the health of human population.
Show more [+] Less [-]On-road vehicle emission inventory and its spatio-temporal variations in North China Plain Full text
2020
Jiang, Peiyu | Zhong, Xi | Li, Lingyu
Vehicle emissions are a major contributor to air pollution in China. In this study, a high-resolution inventory of eight on-road vehicle-emitted pollutants in 53 cities within the North China Plain (NCP) was established for 152 sub-sources. Monthly emission factors were then simulated using the COPERT v5 model and their spatial distribution at 4 km × 4 km resolution was allocated based on the transportation network. In 2017, emissions of BC, CO, NH₃, NMVOCs, NOₓ, PM₁₀, PM₂.₅, and SO₂ were 38.3, 2900, 21.8, 578, 2460, 113, 85.9, and 4.7 kt, respectively. These emissions and their sources differed between cities, mainly due to different vehicle populations, fleet compositions, emission share rates of different vehicle types, and emission standards in each city. Small-medium petrol passenger cars and both 20–26 t and 40–50 t heavy-duty diesel trucks of China 3 and 4 emissions standards were the main contributors for all pollutants. Higher cold-start emission factors caused higher emissions of CO, NMVOCs, NOₓ, and PM₂.₅ in winter. The cities of Beijing, Zhengzhou, Tianjin, Tangshan, Xuzhou, Qingdao, Jinan, Jining, and Zibo had the highest emission intensities. Overall, emissions decreased from the city centers toward surrounding areas. The higher contributions of heavy-duty trucks meant that higher emissions appeared along highways in a vein-like distribution. These results provide a theoretical basis for the effective prevention and control of air pollution in the NCP.
Show more [+] Less [-]The effect of intervention in nickel concentrations on benthic macroinvertebrates: A case study of statistical causal inference in ecotoxicology Full text
2020
Takeshita, Kazutaka M. | Hayashi, Takehiko I. | Yokomizo, Hiroyuki
Field survey-based ecological risk assessments for trace metals are conducted to examine the necessity and/or effectiveness of management intervention, such as setting of environmental quality standards. Observational datasets often involve confounders that may bias estimation of the effects of intervention (e.g., reduction of trace-metal concentrations through regulation). The field of ecotoxicology lags behind some other research fields in understanding proper analytical procedures for causal inference from observational datasets; there are only a few field survey-based ecotoxicological studies that have explicitly controlled for confounders in their statistical analyses. In the present study, we estimated the effect of intervention in nickel concentrations on Ephemeroptera, Plecoptera, and Trichoptera richness in rivers in Japan. We also provide detailed explanations for the backgrounds of spurious associations derived from confounders and on proper analytical procedures for obtaining an unbiased estimate of the targeted intervention effect by using regression analysis. We constructed a multiple regression model based on a causal diagram for aquatic insects and environmental factors, and on “the backdoor criterion,” that enabled us to determine the set of covariates required to obtain an unbiased estimate of the targeted intervention effect from regression coefficients. We found that management intervention in nickel concentrations may be ineffective compared to intervention in organic pollution, and that analysis ignoring the confounders overestimated the effect of intervention in nickel concentrations. Our results highlight the fact that confounders can lead to misjudging the necessity for management of anthropogenic chemical substances. Confounders should be explicitly specified and statistically controlled to achieve a comprehensive assessment of ecological risks for various substances.
Show more [+] Less [-]Using a distributed air sensor network to investigate the spatiotemporal patterns of PM2.5 concentrations Full text
2020
Cao, Rong | Li, Bai | Wang, Zhanyong | Peng, Zhong-Ren | Tao, Shikang | Lou, Shengrong
Spatiotemporal variations in PM₂.₅ are a key factor affecting personal pollution exposure levels in urban areas. However, fixed-site monitoring stations are so sparsely distributed that they hardly capture the dynamic and fine-scale variations in PM₂.₅ in urban areas with complex geographical features and urban forms. Recently, a distributed air sensor network (DASN) was deployed in Dezhou city, China, to monitor fine-scale air pollution information and obtain deep insight into variations in PM₂.₅. Based on the data collected by the DASN, this paper investigated the spatiotemporal patterns of PM₂.₅ using the time-series clustering method. The results demonstrated that there were four stages of PM₂.₅ daily variations, i.e., accumulation, continuous pollution, dispersion, and cleaning. Generally, the stage of dispersion occurred more rapidly than the stage of accumulation, and PM₂.₅ accumulated easily in warm and humid weather with low wind speeds. However, the stage of dispersion was affected mainly by high wind speeds and precipitation. Additionally, the results suggested that four variation stages did not strictly correspond to seasonal divisions. The spatial distributions of PM₂.₅ revealed that the main pollution source was located in a southeastern industrial park, which exhibited a significant impact throughout the four stages. Considering both the temporal and spatial characteristics of PM₂.₅, this study successfully identified pollution hotspots and confirmed the effect of industrial parks. The study demonstrates that the DASN has high prospective applicability for assessing the fine-scale spatial distribution of PM₂.₅, and the time-series clustering method can also assist environmental researchers in further exploring the spatiotemporal characteristics of urban air pollution.
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