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Enantioselective toxic effects of cyproconazole enantiomers against Rana nigromaculata 全文
2018
Zhang, Wenjun | Cheng, Cheng | Chen, Li | Deng, Yue | Zhang, Luyao | Li, Yao | Qin, Yinan | Diao, Jinling | Zhou, Zhiqiang
The environmental contaminant, especially pesticides, threatened the amphibian population. In this assay, the enantioselective behavior of cyproconazole on Rana nigromaculata was studied. We found LC50 (lethal concentration causing 50% mortality) of 4-enantiomers was nearly twice as 3-enantiomers in 96 h acute toxicity test. Besides, the significant considerable variation of oxidative stress and LDH (lactic dehydrogenase) induced by the four enantiomers indicated that cyproconazole could enantioselectively affect enzymes in tadpoles. Bioaccumulation experiments showed the order of cyproconazole in the tadpoles was 4-enantiomers>3- enantiomers>2- enantiomers>1- enantiomers during the exposure for 28d. In tissue distribution test, cyproconazole was formed and accumulated in order of 4-enantiomers>2-enantiomers>3- enantiomers>1- enantiomers, except that in the gut. During the elimination experiment, cyproconazole was rapidly eliminated by 95% within the only 24 h. These results suggested that the influence of enantioselective behavior should consider when assessing ecological risk of chiral pesticides to amphibians.
显示更多 [+] 显示较少 [-]Seasonal contribution of assessed sources to submicron and fine particulate matter in a Central European urban area 全文
2018
Samek, Lucyna | Stegowski, Zdzislaw | Styszko, Katarzyna | Furman, Leszek | Fiedor, Joanna
This study presents the air pollution findings of the submicron (PM1) and fine (PM2.5) particulate matter. The submicron particles are entirely absorbed by the human body and they cause the greatest health risk. For the PM2.5 concentration, there are yearly and/or daily limit values regulations by the European Union (EU) and World Health Organization (WHO). There are no such regulations for PM1 but for health risk reason the knowledge of its concentration is important. This paper presents the seasonal concentration contribution of PM1 and PM2.5, their chemical composition and assessed three basic sources. Daily samples of both fractions were collected from 2nd July 2016 to 27th February 2017 in Krakow, Poland. Apart from PM1 and PM2.5 the concentration of 16 elements, 8 ions and BC for each samples were measured. Based on these chemical species the positive matrix factorization (PMF) receptor modeling was used for the determination of three main sources contribution to the PM1 and PM2.5 concentrations. Daily average concentrations of PM2.5 were 12 μg/m3 in summer and 60 μg/m3 in winter. For PM1 it was 6.9 μg/m3 in summer and 17.3 μg/m3 in winter. These data show a significant difference in percentage contribution of PM1 in PM2.5 in summer (58%) and in winter (29%).For the combustion source, the concentrations calculated from PMF modeling in winter were 4.8 μg/m3 for PM1 and 31 μg/m3 for PM2.5. In summer, the concentrations were smaller than 1 μg/m3 for both fractions. Secondary aerosols' concentration for PM1 was 3.4 μg/m3 in summer and 11 μg/m3 in winter - for PM2.5 these were 7.1 μg/m3 and 17 μg/m3 respectively. The third source - soil, industry and traffic together, had small seasonal variation: for PM1 it was from 1.4 to 1.8 μg/m3 and for PM2.5 from 4.7 to 7.9 μg/m3.
显示更多 [+] 显示较少 [-]Potential ecotoxicological effects of elevated bicarbonate ion concentrations on marine organisms 全文
2018
Gim, Byeong-Mo | Hong, Seongjin | Lee, Jung-Suk | Kim, Nam-Hyun | Kwon, Eun-Mi | Gil, Joon-Woo | Lim, Hyun-Hwa | Jeon, Eui-Chan | Khim, Jong Seong
Recently, a novel method for carbon capture and storage has been proposed, which converts gaseous CO2 into aqueous bicarbonate ions (HCO3−), allowing it to be deposited into the ocean. This alkalinization method could be used to dispose large amounts of CO2 without acidifying seawater pH, but there is no information on the potential adverse effects of consequently elevated HCO3− concentrations on marine organisms. In this study, we evaluated the ecotoxicological effects of elevated concentrations of dissolved inorganic carbon (DIC) (max 193 mM) on 10 marine organisms. We found species-specific ecotoxicological effects of elevated DIC on marine organisms, with EC50-DIC (causing 50% inhibition) of 11–85 mM. The tentative criteria for protecting 80% of individuals of marine organisms are suggested to be pH 7.8 and 11 mM DIC, based on acidification data previously documented and alkalinization data newly obtained from this study. Overall, the results of this study are useful for providing baseline information on ecotoxicological effects of elevated DIC on marine organisms. More complementary studies are needed on the alkalinization method to determine DIC effects on seawater chemistry and marine organisms.
显示更多 [+] 显示较少 [-]Impact of prenatal heavy metal exposure on newborn leucocyte telomere length: A birth-cohort study 全文
2018
Wai, Kyi Mar | Umezaki, Masahiro | Kosaka, Satoko | Mar, Ohn | Umemura, Mitsutoshi | Fillman, Toki | Watanabe, Chiho
Arsenic, cadmium and lead are toxic environmental contaminants. They were shown to be associated with telomere length (TL) in adults. Although they can cross the placental barrier, the effect of prenatal exposure of these metals on newborn TL is unknown. The aim of this study was to examine whether prenatal exposure to heavy metals has an impact on newborn leucocyte TL. A birth-cohort study was conducted with 409 pregnant women and their newborns in Myanmar. During the first visit, face-to-face interviews were conducted, and maternal spot urine sampling was performed. Cord blood samples were collected during follow-up. Urinary heavy metal concentration was measured by ICP-MS and adjusted for creatinine. Relative TL was measured by quantitative real-time polymerase chain reaction. The extent of prenatal arsenic, cadmium and lead exposure and their associations with newborn leucocyte TL were assessed using multivariate linear regression. The median values of maternal urinary arsenic, cadmium, and lead concentrations were 73.9, 0.9, and 1.8 μg/g creatinine, respectively. Prenatal arsenic and cadmium exposure was significantly associated with newborn TL shortening (lowest vs highest quartile, coefficient = - 0.13, 95% CI: - 0.22, - 0.03, p = 0.002, and coefficient = - 0.17, 95% CI: - 0.27, - 0.07, p = 0.001, respectively), and the associations remained robust after adjusting for confounders. There was no significant association between prenatal lead exposure and newborn TL. The present study identified the effect of arsenic and cadmium exposure on TL shortening, even in utero exposure at a lower concentration.
显示更多 [+] 显示较少 [-]Microplastic abundance and characteristics in French Atlantic coastal sediments using a new extraction method 全文
2018
Phuong, Nam Ngoc | Poirier, Laurence | Lagarde, Fabienne | Kamari, Abderrahmane | Zalouk-Vergnoux, Aurore
The ubiquitous presence of microplastics (MPs) has been demonstrated in all environmental compartments in the recent years. They are detected in air, freshwater, soil, organisms and particularly in marine ecosystems. Since sediments are known to be the major sink of many organic and inorganic pollutants, the aim of this study was to develop and validate a fast and cheap methodology to assess the MP contamination in intertidal sediments from the Gulf of Biscay (Pays de la Loire region, France). Sediments were sampled at three locations (Pays de la Loire region, France) and during two seasons: October 2015 and March 2016. The analytical protocol involved MP extraction from dried sediments using milliQ water and a centrifugation technique. After a filtration step of supernatants, MPs were detected and directly identified on the membrane filters using μFTIR spectroscopy in reflection mode. For the first time, the number of replicates allowing to obtain a satisfying representativeness of the whole sampled sediment was also evaluated at 10 replicates of 25 g each. The average number of MPs in sediments was 67 (±76) MPs/kg dw (N = 60) with no significant difference between sites and seasons. Ten different compositions of MPs were defined by μFT-IR with a high proportion of polypropylene (PP) and polyethylene (PE), 38 and 24%, respectively. Among MPs, mainly fragments (84%) were observed with main size classes corresponding to [>100 μm] and [50–100 μm] but no particles > 1 mm could be found suggesting that mainly small microplastics (<1 mm) were subject to vertical transport.
显示更多 [+] 显示较少 [-]Distribution and availability of cadmium in profile and aggregates of a paddy soil with 30-year fertilization and its impact on Cd accumulation in rice plant 全文
2018
Rao, Zhong-Xiu | Huang, Dao-You | Wu, Jin-Shui | Zhu, Qi-Hong | Zhu, Han-Hua | Xu, Chao | Xiong, Jie | Wang, Hui | Duan, Ming-Meng
The research was conducted to investigate the accumulation, distribution and availability of Cd in paddy soil and their relation to Cd in rice plants under 30-year fertilization regimes. Six treatments were involved in the study: control without fertilization (CK), chemical fertilizer (NPK), high nitrogen chemical fertilizer (HN), rice straw incorporation (ST), low and high dosage of manure fertilizer (LM and HM). Total and DTPA extractable concentration of Cd (T-Cd and DTPA-Cd) in bulk soils (20 cm topsoil), profiles (0–60 cm) and aggregates (>2, 1–2, 0.5–1, 0.25–0.5, 0.053–0.25 and < 0.053 mm) were investigated. The Cd concentration in relevant rice plant (roots, stems, leaves, husks and grains) were also analyzed. Manure fertilizers caused T-Cd accumulation in bulk soil with a significant increase of 36.2% in LM and 81.2% in HM. Similar impacts of manure fertilizers were observed in DTPA-Cd in the bulk soil. Further, the HM generated a further accumulation in deeper soil layers, presenting a remarkable increase of T-Cd (28.3%–225%) in 10–40 cm and DTPA-Cd (116%–158%) in 10–30 cm profiles. Moreover, the continuous application of manure fertilizers enhanced the availability of Cd in all aggregate size classes with an increase of 17.3%–87.8% in DTPA-Cd. Organic fertilizers (LM, HM and ST) heightened the content of Cd (38.0%–152%) in all parts of rice plant. The accumulation of Cd in rice plants was directly affected by fertilization regimes and Cd availability in the 10–20 cm soil layers and 0.25–0.5 mm aggregates. In conclusion, long-term application of manures resulted in increasing availability of Cd in aggregates and in topsoil and subsoil layers, which accordingly enhanced the accumulation of Cd in rice plants.
显示更多 [+] 显示较少 [-]COPD rat model is more susceptible to cold stress and PM2.5 exposure and the underlying mechanism 全文
2018
Zhang, Kai | Guo, Lei | Wei, Qiaozhen | Song, Quanquan | Liu, Jiangtao | Niu, Jingping | Zhang, Li | Ruan, Ye | Luo, Bin
The purpose of this study is to verify the hypothesis that chronic obstructive pulmonary disease (COPD) model rat is more susceptible to cold stress and fine particulate matter (PM2.5) exposure than the healthy rat, and explore the related mechanism. COPD rat model, established with cigarette smoke and lipopolysaccharide intratracheal instillation, were exposed to cold stress (0 °C) and PM2.5 (0, 3.2, 12.8 mg/ml). After that, the levels of superoxide dismutase, inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α), monocyte chemotactic protein 1 (MCP-1) and angiotensin Ⅱ (Ang-Ⅱ) in lung were measured, as well as the expression levels of lung 8-hydroxy-2-deoxyguanosine (8-OHdG), nuclear factor kappa B (NF-κB), heme-oxygenase-1 (HO-1) and nuclear factor erythroid-2-related factor 2 (Nrf2). There were significant positive relationships between PM2.5 and lung level of iNOS, TNF-α, MCP-1 and Ang-Ⅱ, lung function and pathologic damage in COPD rats. The HO-1, NF-κB and 8-OHdG were found highly expressed in COPD rat lung, particularly at the higher PM2.5 dose of cold stress groups, while Nrf2 was found declined. Thus, COPD rats may be more susceptible to cold stress and PM2.5 exposure. Cold stress may aggravate PM2.5-induced toxic effects in the lung of COPD rats through increasing Ang-Ⅱ/NF-κB signaling pathway and suppressing Nrf2 signaling pathway.
显示更多 [+] 显示较少 [-]Prenatal exposure to polychlorinated biphenyl and umbilical cord hormones and birth outcomes in an island population 全文
2018
Tang, Mengling | Yin, Shanshan | Zhang, Jianyun | Chen, Kun | Jin, Mingjuan | Liu, Weiping
Prenatal exposure to polychlorinated biphenyl (PCB) is suspected to interfere with fetal development including reproductive and thyroid function and birth outcomes, but published evidence are still sparse. We designed a cross-sectional study to analyze the associations between PCB levels in umbilical cord sera and hormones and birth outcomes of mothers and newborns who are residents from an island. Seven indicator-PCB (PCB-28, 52, 101, 118, 138, 153, 180), and five reproductive hormones including luteotropic hormones (LH), estradiol (E2), testosterone (T), follicle-stimulating hormones (FSH) and anti-Mullerian hormones (AMH), and three thyroid hormones including tri-iodothyronine (T3), tetra-iodothyronine (T4) and thyroid stimulating hormones (TSH) were measured in 106 cord sera specimens. Birth outcomes include birth weight, length, head circumference, and gestational age. Multiple linear regression and quartile regression were used to analyze the associations between PCB and each of the hormones and birth outcomes, adjusting for selected potential confounders. The median value of total PCB in umbilical cord sera was 2.02 μg L−1 (IQR, 1.13–4.64). Several negative associations between PCB exposure and reproductive hormones were found. Among them, the β value of PCB-101 for FSH reached −0.38 (95%CI, −0.69, −0.07; p = 0.02). Moreover, we also found some sex-specific associations i.e. PCB-28 was negatively correlated with LH and T and PCB-118 was negatively correlated with T in male newborns but not in female newborns. The associations between PCB and birth outcomes seem to differ by molecular weight of the PCB congeners i.e. the low-chlorinated PCB congeners were negatively associated with gestational age and head circumference while high-chlorinated PCB congeners were positively associated birth weight and gestational age. In this study, we found that PCB congeners with different molecular weight has different associations with hormones and birth outcomes, and future studies are recommended to investigate underlying mechanisms of these associations.
显示更多 [+] 显示较少 [-]New insights into the mechanism of phthalate-induced developmental effects 全文
2018
Mu, Xiyan | Huang, Ying | Li, Jia | Yang, Ke | Yang, Wenbo | Shen, Gongming | Li, Xuxing | Lei, Yunlei | Pang, Sen | Wang, Chengju | Li, Xuefeng | Li, Yingren
To investigate the biological pathways involved in phthalate-induced developmental effects, zebrafish embryos were exposed to different concentrations of di-(2-ethylhexyl) (DEHP) and di-butyl phthalate (DBP) for 96 h. Embryonic exposure to DEHP and DBP induced body length decrease, yolk sac abnormities, and immune responses (up-regulation of immune proteins and genes). The lipidomic results showed that at a concentration of 50 μg/L, DEHP and DBP significantly reduced the levels of fatty acids, triglycerides, diacylglycerol, and cholesterol. These effects are partly explained by biological pathway enrichment based on data from the transcriptional and proteomic profiles. Co-exposure to DBP and ER antagonist did not significantly relieve the toxic symptoms compared with exposure to DBP alone. This indicates that phthalate-induced developmental abnormities in zebrafish might not be mediated by the ER pathway. In conclusion, we identified the possible biological pathways that mediate phthalate-induced developmental effects and found that these effects may not be driven by estrogenic activation.
显示更多 [+] 显示较少 [-]The influence of three e-cigarette models on indoor fine and ultrafine particulate matter concentrations under real-world conditions 全文
2018
Volesky, Karena D. | Maki, Anthony | Scherf, Christopher | Watson, Louis | Van Ryswyk, Keith | Fraser, Bruce | Weichenthal, Scott A. | Cassol, Edana | Villeneuve, Paul J.
Electronic cigarette (e-cigarette) use has steadily increased since 2010. Indoor e-cigarette use exposes bystanders to a new source of particulate matter (PM) air pollution. Elevated short-term exposures to PM with a lower measuremented aerodynamic diameter (≤2.5 μm), PM₂.₅ and ultrafine particles (UFPs) have been linked to increased risk of adverse respiratory and cardiac events. This exposure study estimated concentrations of PM₂.₅ and UFPs from indoor e-cigarette use at 0.5 meters (m) and 1 m away from an e-cigarette user and investigated whether these indoor concentrations varied across three common e-cigarette models. One e-cigarette user tested three different e-cigarettes containing the same nicotine solution on three separate occasions and measured concentrations on PM₂.₅ and UFPs at 0.5 and 1 m in a ∼38 m³ office. Continuous measures of PM₂.₅ and UFPs were taken for 5.5 min before e-cigarette use, then the user puffed seven times for 6.5 min (exposure), and for 10 min after ceasing e-cigarette use. Following the initiation of e-cigarette use, levels of PM₂.₅ increased 160-fold at a distance of 0.5 m, and 103-fold at 1 m. The corresponding increases in UFP counts were 5.2, and 3.0-fold higher, respectively. The PM₂.₅ concentrations and UFP counts between e-cigarette models were statistically significantly different at 1 m, but not at 0.5 m. There was substantial variability between distances, e-cigarettes, and replicates. This study indicates that e-cigarette vapors influence PM₂.₅ and UFPs concentrations/counts at close proximity distances indoors; additional research is needed to characterize the composition of those particles and evaluate the impacts of other e-cigarette solutions on indoor air quality.
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