细化搜索
结果 1-10 的 42
Do toxicokinetic and toxicodynamic processes hold the same for light and heavy rare earth elements in terrestrial organism Enchytraeus crypticus?
2020
Huang, Xueying | He, Erkai | Qiu, Hao | Zhang, Lulu | Tang, Yetao | Zhao, Chunmei | Li, Min | Xiao, Xue | Qiu, Rongliang
The widespread use of rare earth elements (REEs) in numerous sectors have resulted in their release into the environment. Existing knowledge about the effects of REEs were acquired mainly based on toxicity tests with aquatic organisms and a fixed exposure time, Here, the dynamic accumulation and toxicity of REEs (La, Ce, and Gd) in soil organism Enchytraeus crypticus were determined and modeled by a first-order one-compartment model and a time-toxicity logistic model, respectively. Generally, the accumulation and toxicity of REEs were both exposure level- and time-dependent. The overall uptake rate constants were 2.97, 2.48, and 2.38 L kg⁻¹d⁻¹ for La, Ce, and Gd, respectively. The corresponding elimination rate constants were 0.99, 0.78, and 0.56 d⁻¹, respectively. The worms exhibited faster uptake and elimination ability for light REEs (La and Ce) than for heavy REEs (Gd). For all three REEs, the LC50 values based on exposure concentrations decreased with time and reached ultimate values after approximately 10 d exposure. The estimated ultimate LC50 values (LC50∞) were 279, 334, and 358 mg L⁻¹ for Ce, Gd, and La, respectively. When expressed as body concentration, the LC50ᵢₙₜₑᵣ value was almost constant with time, demonstrating that internal body concentration could be a better indicator of dynamic toxicity of REEs than external dose. This study highlights that specific REE and exposure time should be taken into account in accurately assessing risk of REEs.
显示更多 [+] 显示较少 [-]Urbanization and cattle density are determinants in the exposure to anticoagulant rodenticides of non-target wildlife
2019
López-Perea, Jhon J. | Camarero, Pablo R. | Sánchez-Barbudo, Ines S. | Mateo, Rafael
The persistence and toxicity of second generation anticoagulant rodenticides (SGARs) in animal tissues make these compounds dangerous by biomagnification in predatory species. Here we studied the levels of SGARs in non-target species of wildlife and the environmental factors that influence such exposure. Liver samples of terrestrial vertebrates (n = 244) found dead between 2007 and 2016 in the region of Aragón (NE Spain) were analysed. The presence of SGARs was statistically analysed with binary or ordinal logistic models to study the effect of habitat characteristics including human population density, percentage of urban surface, livestock densities and surface of different types of crops. SGARs residues were detected in 83 (34%) of the animals and levels >200 ng/g were found in common raven (67%), red fox (50%), red kite (38%), Eurasian eagle-owl (25%), stone marten (23%), Eurasian buzzard (17%), northern marsh harrier (17%), and Eurasian badger (14%). The spatial analysis revealed that the presence of SGARs residues in wildlife was more associated with the use of these products as biocides in urban areas and cattle farms rather than as plant protection products in agricultural fields. This information permits to identify potential habitats where SGARs may pose a risk for predatory birds and mammals.
显示更多 [+] 显示较少 [-]Relationships between seminal plasma metals/metalloids and semen quality, sperm apoptosis and DNA integrity
2017
Wang, Yi-Xin | Wang, Peng | Feng, Wei | Liu, Chong | Yang, Pan | Chen, Ying-Jun | Sun, Li | Sun, Yang | Yue, Jing | Gu, Long-Jie | Zeng, Qiang | Lu, Wen-Qing
This study aimed to investigate the relationships between environmental exposure to metals/metalloids and semen quality, sperm apoptosis and DNA integrity using the metal/metalloids levels in seminal plasma as biomarkers. We determined 18 metals/metalloids in seminal plasma using an inductively coupled plasma-mass spectrometry among 746 men recruited from a reproductive medicine center. Associations of these metals/metalloids with semen quality (n = 746), sperm apoptosis (n = 331) and DNA integrity (n = 404) were evaluated using multivariate linear and logistic regression models. After accounting for multiple comparisons and confounders, seminal plasma arsenic (As) quartiles were negatively associated with progressive and total sperm motility using multivariable linear regression analysis, which were in accordance with the trends for increased odds ratios (ORs) for below-reference semen quality parameters in the logistic models. We also found inverse correlations between cadmium (Cd) quartiles and progressive and total sperm motility, whereas positive correlations between zinc (Zn) quartiles and sperm concentration, between copper (Cu) and As quartiles and the percentage of tail DNA, between As and selenium (Se) quartiles and tail extent and tail distributed moment, and between tin (Sn) categories and the percentage of necrotic spermatozoa (all Ptrend<0.05). These relationships remained after the simultaneous consideration of various elements. Our results indicate that environmental exposure to As, Cd, Cu, Se and Sn may impair male reproductive health, whereas Zn may be beneficial to sperm concentration.
显示更多 [+] 显示较少 [-]Industrial water pollution, water environment treatment, and health risks in China
2016
Wang, Qing | Yang, Zhiming
The negative health effects of water pollution remain a major source of morbidity and mortality in China. The Chinese government is making great efforts to strengthen water environment treatment; however, no studies have evaluated the effects of water treatment on human health by water pollution in China. This study evaluated the association between water pollution and health outcomes, and determined the extent to which environmental regulations on water pollution may lead to health benefits. Data were extracted from the 2011 and 2013 China Health and Retirement Longitudinal Study (CHARLS). Random effects model and random effects Logit model were applied to study the relationship between health and water pollution, while a Mediator model was used to estimate the effects of environmental water treatment on health outcomes by the intensity of water pollution. Unsurprisingly, water pollution was negatively associated with health outcomes, and the common pollutants in industrial wastewater had differential impacts on health outcomes. The effects were stronger for low-income respondents. Water environment treatment led to improved health outcomes among Chinese people. Reduced water pollution mediated the associations between water environment treatment and health outcomes. The results of this study offer compelling evidence to support treatment of water pollution in China.
显示更多 [+] 显示较少 [-]Association between urinary concentration of phthalate metabolites and impaired renal function in Shanghai adults
2019
Chen, Jingsi | Zhou, Xiaofeng | Zhang, Han | Liu, Yueming | Cao, Chen | Dong, Ruihua | Yuan, Yaqun | Wang, Min | Lu, Yuanan | Wu, Min | Li, Shuguang | Chen, Bo
Exposure to phthalates is reported to be associated with increased incidence of microalbuminuria and low-grade albuminuria in children and adolescents. However, this phenomenon of phthalate-related nephrotoxicity is unknown in adults.Urine samples of 1663 adults from the 2012 Shanghai Food Consumption Survey (SHFCS) were measured for 10 metabolites of 6 phthalates and for renal function parameters. Their associations were explored by linear and logistic regression models.Multivariate linear regression analysis showed that all three renal function parameters (albumin-to-creatinine ratio (ACR), β2-microglobulin (B2M), and N-acetyl-β-d-glucosaminidase (NAG)) are positively associated with six metabolites, including mono-benzylphthalate (MBzP), mono-2-ethylhexylphthalate (MEHP), mono-2-ethyl-5-oxohexyphthalate (MEOHP), mono-2-ethyl-5-hydroxyhexylphthalate (MEHHP), mono-2-ethyl-5-carboxypentylphthalate (MECPP), and mono-2-carboxymethyl-hexyl phthalate (MCMHP) (P < 0.05). Logistic analysis showed that the prevalence of hyperALBuria, hyperB2Muria, hyperNAGuria, or potentially impaired renal function (PIRF) were positively associated with urinary levels of MBzP, MEOHP, and MECPP, respectively (P < 0.05). Co-exposure to identified risk metabolites monoethylphthalate (MEP), MBzP, MEHP, MEOHP, MECPP, MEHHP, and MCMHP increased the risk of having impaired renal function.Certain metabolites of phthalates, including bis (2-ethylhexyl) phthalate (DEHP) and benzyle butyl phthalate (BBzP), were associated with impaired renal function in Shanghai adults.
显示更多 [+] 显示较少 [-]A multivariate approach to analyzing functional redundancy of marine periphytic ciliates during the colonization process for bioassessment in coastal ecosystems
2017
Xu, Guangjian | Zhong, Xiaoxiao | Warren, Alan | Xu, Henglong
Functional redundancy is a useful tool for determining functional compensation and for reducing “signal to noise” ratios of full-species datasets in community-based monitoring programs. The functional redundancy of marine periphytic ciliate communities during the colonization process in coastal waters of the Yellow Sea, China, was analyzed using a peeling procedure (BVSTEP). Four response units (RUs) with trophic-functional equivalents were identified from the full 77-species dataset. These RUs, which comprised four, seven, six and six species respectively, represented a clear variation in trophic-functional structures across the levels of functional redundancy. RU1 was dominated by bacterivores, RU2 and RU3 first by bacterivores then by algivores, and RU4 first by non-selectives and bacterivores then by algivores. The colonization process and growth curve of each RU were significantly well-fitted to the MacArthur-Wilson and logistic models, respectively. These results suggest that RUs can be used as changeable trophic-functional equivalents for bioassessment in marine ecosystems.
显示更多 [+] 显示较少 [-]The impact of environmental regulations on the location choice of newly built polluting firms: based on the perspective of new economic geography
2022
Peng, Na | Zhang, Xiangjian
Based on the unique micro-data of newly built polluting firms for the period of 2009–2018, this paper adopts the conditional logit model to empirically evaluate the impact of environmental regulations on the location choice of polluting firms. Moreover, we extend the theoretical model by considering that the environment regulations not only influence the pollution cost but also the level of technological innovation and labor cost. The empirical results show that polluting firms tend to flow into areas with stringent environmental regulations, which supports the Porter hypothesis, but the effect of environmental regulations have a divergent impact on heavily polluting firms. Heterogeneous analysis indicates that environmental regulations have shown a positive impact on the location choice of private and foreign-funded firms but no significant impact on that of state-owned firms; the impact of environmental regulation is consistent with pollution haven hypothesis for firms in the central region but is in line with Porter hypothesis for firms in other regions. Meanwhile, the probability of air polluting firms entering areas with stricter environmental regulations is higher than that of water-polluting ones. Finally, this paper further empirically tests the conduction mechanism, that is, environmental regulations can affect the location choice of polluting firms by affecting the regional technological innovation capabilities and labor cost.
显示更多 [+] 显示较少 [-]Arsenite removal from drinking water by bark-based magnetic iron oxide particle (BMIOP): a column study
2022
Dhoble, Rajesh M. | Rayalu, Sadhana | Kularkar, Ankush | Hajare, Hemant
The removal of arsenite [As(III)] from drinking water was investigated in a column at flow rates of 2.0 and 5.0 mL/min (up-flow direction) using bark-based magnetic iron oxide particles (BMIOP) prepared by coating (Fe(NO₃)₃.9H₂O) over Tamarindus Indica bark. The BMIOP was compared with regenerated BMIOP, commercial activated carbon, commercial activated alumina (Al₂O₃). At 2.0 mL/min, empty bed contact time (EBCT), breakthrough time (BT), the volume of treated water and breakthrough capacity (BC) on fresh BMIOP were found to be 6.8 min, 33.15 h, 4.380 L and 0.742 mg/g, respectively, and at 5.0 mL/min, were found to be 4.1 min, 13 h, 3.675 L and 0.453 mg/g respectively. EBCT, BT and BC were increased by 65.85%, 155% and 63.79%, respectively, as the flow rate was reduced from 5.0 to 2.0 mL/min. After regeneration of BMIOP, EBCT, BT, saturated time, BC and saturation capacity (SC) were reduced by 21.95%, 15.38%, 55.15%, 16.78% and 29.71%, respectively. The BC of fresh BMIOP was increased by factors 4.15, 3.60 and 1.20 and SC by factors 9.51, 7.88 and 1.42 compared to commercial activated carbon, commercial activated Al₂O₃ and regenerated BMIOP, respectively. Logit model could be used for the design of the adsorption column. Thomas model and artificial neural network (ANN) were applied to predict the characteristic column parameters useful for process design. Quality of treated water meets BIS requirements. Toxicity Characteristic Leaching Procedure (TCLP) and semi-dynamic tests show that the exhausted BMIOP is safe for disposal in a secure landfill; hence, BMIOP has been proved to separate As(III) from water.
显示更多 [+] 显示较少 [-]Simultaneous biodegradation of dimethyl sulfide and 1-propanethiol by Pseudomonas putida S-1 and Alcaligenes sp. SY1: “Lag” cause, reduction, and kinetics exploration
2022
Li, Qian | Tang, Zeqin | Zhang, Jiahui | Hu, Jingtao | Chen, Jianmeng | Chen, Dongzhi
Simultaneous biodegradation of malodorous 1-propanethiol (PT) and dimethyl sulfide (DMS) by Pseudomonas putida S-1 and Alcaligenes sp. SY1 was investigated and the interactions implicated were explored. Results showed that PT was completely degraded in 33 h, while a lag of 10 h was observed for DMS degradation alone, and the lag was even extended to 81 h in the binary mixture. Mechanism analysis found that the lag was mainly attributed to the exposure of DMS degrader (Alcaligenes sp. SY1), rather than PT metabolites and PT degrader. The exposure time and PT concentration also influenced the lag duration much. Citric acid could effectively reduce the lag. Pseudo-first-order model was proved suitable for the description of PT degradation, revealing that PT degradation could be enhanced in presence of DMS with a concentration of < 50 mg L⁻¹. A modified Gompertz model, incorporated the lag phase, was developed for the description of DMS degradation in the mixture, revealing that DMS degradation depended on the initial PT concentration, and when the lag was not considered, PT with low-concentration could promote DMS biodegradation, while a higher concentration (> 20 mg L⁻¹) cast negative effect.
显示更多 [+] 显示较少 [-]Associations between organophosphate esters metabolites and sleep disorder and trouble sleeping in adults: a machine-learning approach
2022
Kang, Xiao | Li, Jingxian | Luo, Jia | Zhang, Dongfeng
Organophosphate esters (OPEs) are used widely as flame retardants and plasticizers. However, the associations between OPEs metabolites and sleep outcomes (sleep disorder and trouble sleeping) remain unknown. Data utilized in this cross-sectional study was from the National Health and Nutrition Examination Survey 2013–2014, including 1393 adults aged ≥ 20 years. We conducted weighted logistic regression and Bayesian kernel machine regression (BKMR) models to analyze the associations between OPEs metabolites and sleep outcomes. We included data from 2011 to 2012 cycle in our sensitivity analysis to explore the association further. Logistic regression model presented a significant positive association between diphenyl phosphate (DPHP) and sleep disorder in all participants (odds ratio (95% confidence interval) for the second quartile was 2.46 (1.85, 3.28)). We observed positive associations between OPEs metabolites and sleep outcomes in males. Among females, no significant association was observed in the logistic model. BKMR presented that dibutyl phosphate (DBUP) was the relatively important exposure. There was a positive association between OPEs metabolites mixture and trouble sleeping. Univariable exposure–response functions demonstrated U-shaped associations between DBUP and sleep outcomes, while bis(2-chloroethyl) phosphate (BCEP) was associated with sleep disorder negatively in females. No substantial changes appeared in the results after including the data from 2011 to 2012 cycle. This current study indicated that OPEs metabolites might be associated with sleep disorder and trouble sleeping, and the associations seemed to be sex-dependent.
显示更多 [+] 显示较少 [-]