细化搜索
结果 571-580 的 4,935
Monitoring of explosive residues in lake-bottom water using Polar Organic Chemical Integrative Sampler (POCIS) and chemcatcher: determination of transfer kinetics through Polyethersulfone (PES) membrane is crucial 全文
2019
Estoppey, Nicolas | Mathieu, Jörg | Gascon Diez, Elena | Sapin, Eric | Delémont, Olivier | Esseiva, Pierre | de Alencastro, Luiz Felippe | Coudret, Sylvain | Folly, Patrick
Between 1920 and 1967, approximatively 8200 tons of ammunition waste were dumped into some Swiss lakes. This study is part of the extensive historical and technical investigations performed since 1995 by Swiss authorities to provide a risk assessment. It aims to assess whether explosive monitoring by passive sampling is feasible in lake-bottom waters. Polar organic chemical integrative sampler (POCIS) and Chemcatcher were first calibrated in a channel system supplied with continuously refreshed lake water spiked with two nitroamines (HMX and RDX), one nitrate ester (PETN), and six nitroaromatics (including TNT). Exposure parameters were kept as close as possible to the ones expected at the bottom of two affected lakes. Sixteen POCIS and Chemcatcher were simultaneously deployed in the channel system and removed in duplicates at 8 different intervals over 21 days. Sorbents and polyethersulfone (PES) membranes were separately extracted and analyzed by UPLC-MS/MS. When possible, a three-compartment model was used to describe the uptake of compounds from water, over the PES membrane into the sorbent. Uptake of target compounds by sorbents was shown not to approach equilibrium during 21 days. However, nitroaromatics strongly accumulated in PES, thus delaying the transfer of these compounds to sorbents (lag-phase up to 9 days). Whereas sampling rate (RS) of nitroamines were in the range of 0.06–0.14 L day⁻¹, RS of nitroaromatics were up to 10 times lower. As nitroaromatic accumulation in PES was integrative over 21 days, PES was used as receiving phase for these compounds. The samplers were then deployed at lake bottoms. To ensure that exposure conditions were similar between calibration and field experiments, low-density polyethylene strips spiked with performance reference compounds were co-deployed in both experiments and dissipation data were compared. Integrative concentrations of explosives measured in the lakes confirmed results obtained by previous studies based on grab sampling.
显示更多 [+] 显示较少 [-]Aluminum distribution heterogeneity and relationship with nitrogen, phosphorus and humic acid content in the eutrophic lake sediment 全文
2019
Lin, Qingwei | Peng, Xue | Liu, Biyun | Min, Fenli | Zhang, Yi | Zhou, Qiaohong | Ma, Jianmin | Wu, Zhenbin
Increasing amount of aluminum (Al) gets into aquatic ecosystem through anthropogenic activity, but the knowledge about Al migration and relationships with sediments possessing different physico-chemical properties in eutrophic lakes is limited. Here, the Al migration rule and relationships with sediment nutritions in the Hangzhou West Lake, China was investigated, where a certain amount of residual Al-salts can enter because of the pre-treatment of the Qiantang River diversion project every day. Results revealed the obvious spatial distribution heterogeneity of Al in sediment vertical direction and horizontal direction following water flow. The Al content in sediment ranged 0.463–1.154 g kg⁻¹ in Maojiabu Lake, and ranged 9.862–40.442 g kg⁻¹ in Xiaonanhu Lake. Higher Al content distributed in upper layer sediment in lake with more disturbance. Total nitrogen (TN) contents were higher 0.917–3.387 mg g⁻¹ and 0.627–0.786 mg g⁻¹ in upper layer sediment than that in lower layer in Maojiabu Lake and Xiaonanhu Lake, respectively. Total phosphorus (TP) content ranged 0.779–2.580 mg g⁻¹, in which IP and Fe/Al-P contributed 24.9–80.8% and 17.0–51.6%, respectively. Correlations between Al content with nutrition, humic acid (HA) etc. of sediment regionally varied in Maojiabu and Xiaonanhu Lake. Spatial distribution of Al-salt in eutrophic lakes closely related with the physico-chemical characteristics of nutrients, humus, human disturbance and water division parameters. Results provides new insight into Al-salts migration and references for Al-risk evaluating in eutrophic lakes.
显示更多 [+] 显示较少 [-]Urinary bisphenol analogues concentrations and biomarkers of oxidative DNA and RNA damage in Chinese school children in East China: A repeated measures study 全文
2019
Zhou, Ying | Yao, Yuan | Shao, Yijun | Qu, Weidong | Chen, Yue | Jiang, Qingwu
The associations between bisphenol analogues (BPs) exposure and oxidative damage was explored in this 3-year longitudinal study of 275 school children in East China. Nine BPs in first morning urine samples were measured to assess BPs exposure, and 8-hydroxydeoxyguanosine (8-OHdG) and 8-oxo-7,8-dihydroguanosine (8-OHG) were measured as biomarkers of oxidative DNA and RNA damage. Linear mixed model (LMM) was used for repeated measures analysis. School children were mainly exposed to BPA, BPS, BPF, and BPAF (detection frequencies: 97.9%, 42.2%, 13.3%, and 12.8%) with median concentrations of 1.55, 0.355, 0.236 and 0.238 μg g⁻¹Cᵣₑ, respectively. An interquartile range (IQR) increase in urinary BPA was significantly associated with 12.9% (95% CI: 6.1%, 19.6%) increase in 8-OHdG and 19.4% (95% CI: 11.7%, 27.1%) increase in 8-OHG, and for total of BPs (the sum of BPA, BPS, BPF, and BPAF), they were 17.4% (95% CI: 8.9%, 26.0%) for 8-OHdG and 25.9% (95% CI: 16.1%, 35.7%) for 8-OHG, respectively. BPS was positively associated with 8-OHG, but not with 8-OHdG. The study found positive associations of urinary levels of BPA and total BPs with 8-OHdG and 8-OHG and indicated that BPs exposure might cause oxidative RNA damage.
显示更多 [+] 显示较少 [-]Tetrabromobisphenol A: Disposition, kinetics and toxicity in animals and humans 全文
2019
Yu, Yunjiang | Yu, Ziling | Chen, Haibo | Han, Yajing | Xiang, Mingdeng | Chen, Xichao | Ma, Ruixue | Wang, Zheng-Dong
Tetrabromobisphenol A (TBBPA) is a nonregulated brominated flame retardant with a high production volume, and it is applied in a wide variety of consumer products. TBBPA is ubiquitous in abiotic matrices, wildlife and humans around the world. This paper critically reviews the published scientific data concerning the disposition, metabolism or kinetics and toxicity of TBBPA in animals and humans. TBBPA is rapidly absorbed and widely distributed among tissues, and is excreted primarily in the feces. In rats, TBBPA and its metabolites have limited systemic bioavailability. TBBPA has been detected in human milk in the general population. It is available to both the developing fetus and the nursing pups following maternal exposure. It has been suggested that TBBPA causes acute toxicity, endocrine disruptor activity, immunotoxicity, neurotoxicity, nephrotoxicity, and hepatotoxicity in animals. Cell-based assays have shown that TBBPA can induce reactive oxygen species in a concentration-dependent manner, and it promotes the production of inflammatory factors such as TNF α, IL-6, and IL-8. Cells exposed to high levels of TBBPA exhibit seriously injured mitochondria and a dilated smooth endoplasmic reticulum. This review will enhance the understanding of the potential risks of TBBPA exposure to ecological and human health.
显示更多 [+] 显示较少 [-]Petroleum hydrocarbon (PHC) uptake in plants: A literature review 全文
2019
Hunt, Lillian J. | Duca, Daiana | Dan, Tereza | Knopper, Loren D.
Crude oil and its constituents can have adverse effects on ecological and human health when released into the environment. The Canadian Council of Ministers of the Environment (CCME) has developed remedial guidelines and a risk assessment framework for both ecological and human exposure to PHC. One of the assumptions used in the derivation of these guidelines is that plants are unable to take up PHC from contaminated soil and therefore subsequent exposure at higher trophic levels is not a concern. However, various studies suggest that plants are indeed able to take up PHC into their tissues. Consumption of plants is a potential exposure pathway in both ecological (e.g., herbivorous and omnivorous birds, and mammals) and human health risk assessments. If plants can uptake PHC, then the current approach for risk assessment of PHC may underestimate exposures to ecological and human receptors. The present review aims to assess whether or not plants are capable of PHC uptake and accumulation. Twenty-one articles were deemed relevant to the study objective and form the basis of this review. Of the 21 primary research articles, 19 reported detectable PHC and/or its constituents in plant tissues. All but five of the 21 articles were published after the publication of the CCME Canada-Wide Standards. Overall, the present literature review provides some evidence of uptake of PHC and its constituents into plant tissues. Various plant species, including some edible plants, were shown to take up PHC from contaminated soil and aqueous media in both laboratory and field studies. Based on the findings of this review, it is recommended that the soil-plant-wildlife/human pathway should be considered in risk assessments to avoid underestimating exposure and subsequent toxicological risks to humans and wildlife.
显示更多 [+] 显示较少 [-]Transcriptomic analysis of short-term 17α-ethynylestradiol exposure in two Californian sentinel fish species sardine (Sardinops sagax) and mackerel (Scomber japonicus) 全文
2019
Renaud, Ludivine | Agarwal, Nisha | Richards, Dylan J. | Falcinelli, Silvia | Hazard, E Starr | Carnevali, Oliana | Hyde, John | Hardiman, Gary
Endocrine disrupting chemicals (EDCs) are substances which disrupt normal functioning of the endocrine system by interfering with hormone regulated physiological pathways. Aquatic environments provide the ultimate reservoir for many EDCs as they enter rivers and the ocean via effluent discharges and accumulate in sediments. One EDC widely dispersed in municipal wastewater effluent discharges is 17α-ethynylestradiol (EE2), which is one of the most widely prescribed medicines. EE2 is a bio-active estrogen employed in the majority of oral contraceptive pill formulations. As evidence of the health risks posed by EDCs mount, there is an urgent need to improve diagnostic tools for monitoring the effects of pollutants. As the cost of high throughput sequencing (HTS) diminishes, transcriptional profiling of an organism in response to EDC perturbation presents a cost-effective way of screening a wide range of endocrine responses. Coastal pelagic filter feeding fish species analyzed using HTS provide an excellent tool for EDC risk assessment in the marine environment. Unfortunately, there are limited genome sequence data and annotation for many of these species including Pacific sardine (Sardinops sagax) and chub mackerel (Scomber japonicus), which limits the utility of molecular tools such as HTS to interrogate the effects of endocrine disruption. In this study, we carried out RNA sequencing (RNAseq) of liver RNA harvested from wild sardine and mackerel exposed for 5 h under laboratory conditions to a concentration of 12.5 pM EE2 in the tank water. We developed an analytical framework for transcriptomic analyses of species with limited genomic information. EE2 exposure altered expression patterns of key genes involved in important metabolic and physiological processes. The systems approach presented here provides a powerful tool for obtaining a comprehensive picture of endocrine disruption in aquatic organisms.
显示更多 [+] 显示较少 [-]Endocrine disrupting chemicals in wild freshwater fishes: Species, tissues, sizes and human health risks 全文
2019
Zhou, Xinyi | Yang, Zhaoguang | Luo, Zhoufei | Li, Haipu | Chen, Guoyao
Increasing attention has been devoted to the adverse effects of endocrine disrupting chemicals (EDCs) on aquatic environments, such as water, sediment and sludge. To date, few studies have investigated the bio-accumulative characteristics of EDCs in different tissues of diverse wild freshwater fish species and their combined impacts on human health. Five EDCs were investigated in the muscle, liver, gill and, especially, gonad of three fish species collected from the Xiangjiang River, southern China. Carnivorous Siniperca Chuatsi or omnivorous Cyprinus Carpio accumulated higher contents of bisphenol A (BPA) and estrone than herbivorous Parabramis Pekinensis in muscle. Furthermore, 4-n-nonylphenol and estrone were found at higher levels and more frequently in the liver, implying that the liver played an important role in basic metabolism for accumulation, biotransformation and excretion of EDCs. Highest concentrations of BPA found in the gonad revealed that the BPA may pose a serious threat to the reproductive system of aquatic organisms. The mean liver/muscle concentration ratios of 4-n-nonylphenol, BPA, estrone and 17α-ethynyl estradiol confirmed the prolonged exposure of the fish to these EDCs. In addition, the relationships between the fish sizes and the EDC concentrations analyzed by Pearson correlation analysis implied that the bioaccumulation of diethylstilbestrol and BPA increased with the growth of Parabramis Pekinensis, and there was a balance between the uptake rate and elimination rate of EDCs in Siniperca Chuatsi and Cyprinus Carpio. Most importantly, the cumulative impacts of combined EDCs on human health by fish consumption were evaluated. The total estradiol equivalent quantity of estrogens was higher than that of phenols. Also, based on the results of the Monte-Carlo simulation, the 95th percentile values of the total estimated daily intakes from consuming the three freshwater fish species from the Xiangjiang River were higher than the acceptable daily intake.
显示更多 [+] 显示较少 [-]Concentrations and gas-particle partitioning of atmospheric reactive mercury at an urban site in Beijing, China 全文
2019
Zhang, Huan | Wang, Zhangwei | Wang, Chunjie | Zhang, Xiaoshan
Measurements of speciated atmospheric mercury play a key role in identifying mercury behavior in the atmosphere. In this study, we measured speciated atmospheric mercury, including gaseous elemental mercury (GEM), reactive gaseous mercury (RGM), and particulate bound mercury (PBM) (<2.5 μm), in 2015 and 2016 at an urban site in Beijing, China. The mean concentrations of GEM, RGM, and PBM were 4.70 ± 3.53 ng m−3, 18.47 ± 22.27 pg m−3, and 85.18 ± 95.34 pg m−3, respectively. The concentration of PM2.5 significantly affected the distribution of reactive mercury between the gaseous and particulate phases. With the raising of PM2.5 levels, PBM concentrations increased, on the contrary, the concentrations of RGM decreased gradually. The mean concentration of PBM during air-pollution events was more than three times that during clear days. During days with air pollution, the relative humidity significantly affected the gas-particle partitioning of reactive mercury. The linear relationships between gas-particle partitioning coefficient and meteorological factors (air temperature and relative humidity) were obtained over the four seasons. The data also showed that the gas-particle partitioning coefficient of reactive mercury was related to particle composition (e.g., Cl−, BC). The data present in this paper suggested the influence of anthropogenic emissions on reactive mercury in Beijing urban. And the findings will contribute to understand the gas-particle partitioning of reactive mercury and its influencing factors with complex urban pollution.
显示更多 [+] 显示较少 [-]Effect of flow and humidity on indoor deposition of particulate matter 全文
2019
Kim, Jeong Jae | Hann, Taeseong | Lee, Sang Joon
The removal of particulate matter (PM) is an important issue in public health and the global atmospheric environment. Various PM removal methods have been suggested to effectively remove PM particles. However, the effects of various factors on PM deposition are not completely clear. We quantitatively investigated the effects of flow and humidity difference in a closed chamber on PM deposition. To elucidate the parameters affecting the deposition of PM particles, PM removal efficiency and deposition constant were examined at different flow rates, flow directions, and relative humidity (RH) inside the closed system. The highest PM deposition rate was achieved under humid condition with the upward direction flow at a fan speed of RPM = 150. Mean velocity fields inside the test chamber were obtained by a particle image velocimetry (PIV) technique to quantitatively examine the effect of flow conditions on the PM deposition. The flow structure and RH inside the closed chamber have significant influence on PM deposition.
显示更多 [+] 显示较少 [-]Toxicity of nano-CuO particles to maize and microbial community largely depends on its bioavailable fractions 全文
2019
Pu, Shengyan | Yan, Chun | Huang, Hongyan | Liu, Shibin | Deng, Daili
The environmental consequences of nano-CuO particles have gained significant attention in recent decades. Identification of the mechanisms for soil and plant responses with respect to the chemical speciation of nano-CuO (mainly the exchangeable and reducible fractions) remains scarce. Here, we analyzed different chemical speciation of Cu and DTPA-extractable Cu over 42 days in (1) control soil without Cu addition; (2) soil treated with nano-CuO particles; and (3) soil treated with CuSO₄ solution. The applied dose was 500 mg Cu kg⁻¹ and maize was grown in these soils. Plant growth was inhibited, but the inhibition by nano-CuO was slightly weaker compared to CuSO₄. Cu accumulations were similar in the roots for CuSO₄ and nano-CuO treatments, but significantly higher in the shoots for CuSO₄ treatment. This indicates that Cu from nano-CuO-treated soils mainly accumulated in roots but rarely transferred to shoots. Enzyme activities on the rhizoplane visualized by zymography were strongly depressed by CuSO₄ but slightly inhibited by nano-CuO. Microbial community diversity measured by 16S rRNA was the lowest in CuSO₄-treated soils among three treatments. These results were explained by the following mechanisms: (1) Gradual increases of DTPA-extractable and exchangeable Cu were found in nano-CuO-treated soil, and the final concentrations at day 42 were only half of those in CuSO₄-treated soil; (2) Enzyme activities on the rhizoplane were positively related to soil pH and negatively correlated with DTPA-extractable and exchangeable Cu; (3) Even though reducible Cu in nano-CuO-treated soils was 1.3 times higher than in CuSO₄-treated soils, indicating stronger nano-accrued oxidative stress in nano-CuO-treated soils, the toxicity induced by nano-CuO particles was still weaker than CuSO₄. Nevertheless, the toxicity of Cu particles to plants and microbes mainly depends on the gradually-released bioavailable Cu. This demonstrates the greater importance of bioavailable Cu concentrations for toxicity modulation rather than the scale of Cu particles.
显示更多 [+] 显示较少 [-]