Modelling the fate of mirex and lindane in Lake Ontario,off the Niagara river mouth

A seasonally averaged (June–November) fate model (toxfate) of organic contaminants was used to assess the relative importance of transport, degradation and volatization processes in the Niagara River and in Lake Ontario near the river mouth. The model predicts concentrations in several compartments, including suspended sediments, water, plankton, and fish. Two contaminants were modelled, Mirex and α-hexachlorocyclohexane (Lindane). Simulations show that the largest amount of contaminants is usually in the water fraction. About 70% of Mirex is in the water at the mouth of the Niagara River, compared with 99% for Lindane. For these two contaminants, the processes of degradation and volatilization are two to three orders of magnitude slower than the rate of transport through the river and the plume. In the water, the most important process is a change of phase, from the dissolved to the adsorbed state. This change of state is mostly relevant for strongly hydrophobic compounds like Mirex, and less so for Lindane. Simulations were performed for a 40-day period during which fish concentrations did not reach equilibrium with Mirex, but they did with Lindane. Spatial distributions of these contaminants were also predicted and compared with available data.     

Algae and bacteria consortia for wastewater decontamination and transformation into biodiesel,bioethanol, biohydrogen,biofertilizers and animal feed: a review

Traditional wastewater treatment has been aimed solely at sanitation by removing contaminants, yet actual issues of climate change and depletion of natural resources are calling for methods that both remove contaminants and convert waste into chemicals and fuels. In particular, biological treatments with synergic coupling of microalgae and bacteria appear promising to remove organic, inorganic, and pathogen contaminants and to generate biofuels. Here, we review the use of algae and bacteria in the treatment and valorization of wastewater with focus on cell-to-cell adhesion, wastewater properties, and techniques for algae harvesting and production of biodiesel, bioethanol, biohydrogen, exopolysaccarides, biofertilizers, and animal feeds.

     

Atrazine increases ranavirus susceptibility in the tiger salamander, Ambystoma tigrinum.

Pathogenic diseases and environmental contaminants are two of the leading hypotheses for global amphibian declines, yet few studies have examined the influence of contaminants on disease susceptibility. In this study, we examined effects of ecologically relevant doses of atrazine (0, 1.6, 16, and 160 microg/L), sodium nitrate (0, 6.8, 68 mg/L), and their interactions on susceptibility of four laboratory-bred tiger salamander families to Ambystoma tigrinum virus (ATV), a pathogen implicated in global amphibian die-offs. Salamanders were from Arizona populations where a coevolutionary history with ATV is supported, and thus cofactors rather than recent introduction may contribute to disease epizootics. Use of atrazine and nitrogenous fertilizers are ubiquitous; therefore, the impact of these cofactors on disease susceptibility is an important consideration. Atrazine and sodium nitrate significantly decreased peripheral leukocyte levels, suggesting an impact of these contaminants on the immune system. As expected from this result, atrazine significantly increased susceptibility of larvae to ATV infection. In contrast, nitrate had a marginally significant main effect and significantly decreased infection rate at the highest level. However, neither atrazine nor sodium nitrate had significant effects on viral copy number per individual. These results suggest that ecologically relevant concentrations of atrazine and nitrates have immunosuppressive effects, and atrazine may contribute to ATV epizootics, raising concerns about the influence of contaminants on diseases in general.     

Interactive effects of single,binary and trinary trace metals (lead,zinc and copper) on the physiological responses of Kandelia obovata seedlings

Environmental Geochemistry and Health - Heavy metals are considered important environmental contaminants, and their mixture toxicity on plants has complex mutual interactions. The interactive...     

Predicted distribution of 16 short-chain chlorinated paraffins in air,water, soils and sediments

Environmental Chemistry Letters - Short-chain chlorinated paraffins are industrial contaminants of great concern due to their persistent and toxic characteristics. The predicted distribution of...     

微塑料与污染物相互作用的研究进展

微塑料广泛存在于环境中,其比表面积大、吸附性强,可吸附环境中的重金属、有机物、微生物等污染物,并改变它们在环境中的归趋;同时,这些污染物也会影响微塑料的性质及其在环境中的吸附、迁移、降解等行为,进而对生态环境产生潜在风险.开展微塑料与污染物的相互作用研究是进行微塑料环境风险评价的基础.当前相关研究多集中于微塑料的分布及...     

Industrial organic contaminants: identification,toxicity and fate in the environment

Industrialization and urbanization in the more economically developed countries and also in emerging and developing nations have led to an intensive and still increasing use of water resources. The involved chemical contamination led to a deterioration of aquatic systems in many areas. Industries are important pollution sources and the discharged wastewaters may contain very diverse and potentially harmful organic compound groups. We therefore present here a comprehensive review of the current state of knowledge of organic contaminants from industrial wastewaters. The available studies proved the heterogenic chemical composition of industrial wastewaters, even from the same industry branches, and the presence of heterogenic organic contaminant mixtures from industrial sources in aquatic systems. We conclude that our knowledge of the chemical composition of industrial wastewaters and the occurrence of industrial organic contaminants in the environment is as yet very limited. A combination of chemical and toxicological methods enabled the identification of toxic organic constituents in industrial wastewaters. Chemical evaluations of industrial contamination linked to surveys of environmental impacts could relate toxic effects of field samples to the presence of specific contaminants. Exposure experiments in the field proved the bioaccumulation and toxicity of several industrial compounds. Ecological surveys in industrial areas combined with a comprehensive chemical characterization and toxicity evaluation are so far missing. Some of the identified organic contaminants are related to characteristic industrial production processes, and their presence in water, sediment or biota indicates the input of specific industrial wastewaters. Accordingly, these compounds can be used as industrial markers. We suggest the proceeding application of the marker concept, as markers are useful to verify the input of specific industrial wastewaters to aquatic systems and to investigate the spatial distribution of the emission. Such information helps to disentangle different emission sources for the subsequent investigation of potential impacts in the environment.     

Concentration,sources, influencing factors and hazards of heavy metals in indoor and outdoor dust: A review

Environmental Chemistry Letters - Heavy metals are a common class of toxic contaminants in soil, water and air, yet their occurrence in indoor environments is less known. Heavy metals enter...     

Nanoplastic occurrence,transformation and toxicity: a review

Environmental Chemistry Letters - Nanoplastics are emerging contaminants of concern for living organisms and ecosystems, yet nanoplastics are difficult to extract and analyse. Once released into...     

Concentration enrichment of sparingly soluble contaminants (U,Th and Pb) by erosion and by soil adhesion to plants and skin

Sparingly soluble contaminants are less likely to affect human health through food chain transfers, such as plant uptake or passage through animal-based foods, because mobility in these pathways is limited by solubility. Direct ingestion or inhalation of contaminated soil becomes the dominant pathway. However, both of these can be selective processes. Clay-sized particles carry the bulk of the sparingly soluble contaminants, and mechanisms that selectively remove and accumulate clay from the bulk soil also concentrate the contaminants. Erosion is another process that selectively removes clays. This project examined the degree of clay and contaminant-concentration enrichment that could occur by these processes, using U, Th and Pb as representative contaminants and using a clay and a loam soil. Erosion by water in natural rainfall events caused concentration enrichments up to 7 fold, and enrichments varied with characteristics of the erosion events. Enrichments were higher for the coarser, loam soil. Adhesion to skin gave modest enrichments of 1.3 fold in these soils, but up to 10 fold in sandy soils studied subsequently. Adhesion to plant leaves, where there was no root contact with contaminated soil, gave leaf concentrations comparable to situations where the roots contacted the contaminated soil. Clearly, adhesion to leaves is an important component of plant accumulation of sparingly soluble contaminants.     

Organochlorine Residues in Coastal Birds From the Vellar River Watershed Areas,Parangipettai, Southern India

Organochlorine contaminants (HCHs, DDTs and PCBs) in the muscle tissues of 12 bird species collected from Vellar River watershed areas (S. India) were determined. the accumulation pattern of organochlorine residues in birds of different feeding groups for HCHs and PCBs was: scavengers > inland piscivores > coastal piscivores > insectivores. the pattern for DDTs was: coastal piscivores > scavengers > insectivores > inland piscivores. Scavengers accumulated all the three organochlorines to a higher degree than the other groups of birds. Marked variations in the accumulation pattern by different species and individuals of birds to the same and different organochlorine residues were observed. the differences in the accumulation pattern of residues in different species of birds with similar feeding habits could be attributed to different feeding areas and because migrants are exposed to contaminants in different geographical locations. HCH residues were generally found in higher concentrations than DDTs, reflecting increasing use of HCH pesticides since banning of DDT for agriculture. Levels of PCBs were lower than in birds in developed countries. Results are discussed in relation to future pest control and industrialisation in India.     

联合基于野外的代谢组学和化学分析手段筛选优先关注新兴污染物：在五大湖流域的案例研究

由于毒性评估项目很难与日渐增长的需要测试的污染物保持同步,所以较难将关注点集中在影响水生生态系统的最为生物相关的污染物上。由于评估潜在毒性污染物所造成的生物影响已被证明是有效的,内生性代谢物的研究（代谢组学）对于剔除那些较低可能造成生物影响的污染物或许有一定帮助,从而找出生物重要性最高的污染物。本研究在北美五大湖流域的18个地点针对置于笼中的黑头软口鲦（Pimephales promelas）进行实验。我们测定了水体温度和水样中的污染物浓度（目标污染物132种,检出86种）,并使用1H-NMR谱测量了肝极性提取物中的内生性代谢物。利用偏最小二乘法回归来比对内生性代谢物的相对丰度与污染物浓度和环境温度。结果表明内生性极性代谢物的指标与最多49种污染物存在共同变化。因此我们认为至多52%的检出污染物与内生性代谢物变化的共同变化不显著,表明这些污染物很可能不会在这些地点造成可以检测到的影响。这是通过缩短对于实验地点有着潜在影响的污染物列表从而扫描出检出污染物生物相关性的第一步。类似的信息有助于风险评估者区分不同污染物的重要性并将重点毒性测试放在最为生物相关的污染物上。
精选自Nicol Janecko, Lucie Pokludova, Jana Blahova, Zdenka Svobodova, Ivan Literak. Linking field-based metabolomics and chemical analyses to prioritize contaminants of emerging concern in the Great Lakes basin. Environmental Toxicology and Chemistry: Volume 35, Issue 10, pages 2493–2502, October 2016. DOI: 10.1002/etc.3409
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3409/full
     

Influence of large-spectrum environmental contamination on the micro-meiobenthic assemblages in harbour sediments of the ligurian sea (W Mediterranean)

The concentration of a large spectrum of environmental contaminants (PCBs, PAHs, pesticides and metals) was assessed in surface sediments of two Ligurian harbours (Sanremo and Alassio, NW Mediterranean Sea, Italy) and their relative impact on micro-meiobenthic assemblages was analysed. Concentration, distribution and relative importance of the different contaminants varied considerably between harbours in relation to the different anthropic activities and contamination sources. Results from Principal Component Analysis indicated that high levels of contaminants were typically correlated with low micro-meiobenthic abundance in the sediment. Heavy metals and the organic enrichment were the main factors affecting the distribution and abundance of the bacterial and meiofaunal assemblages in Alassio harbour, whereas hydrocarbons and pesticides played a major role in Sanremo sediments. Neither the bacteria density nor the meiofauna abundance were dependent on sediment grain size, suggesting that micro-meiobenthic parameters may be under the influence of other variables. Our results suggest that high concentrations of contaminants independently from their source or typology are responsible for the impact observed on micro-meiobenthic assemblages in these harbours.     

Identification and ranking of the risky organic contaminants in the source water of the Danjiangkou reservoir

The Danjiangkou reservoir was selected to provide the source water for the middle routes of the South to North Water Transfer Project, which has provoked many environmental concerns. To date, investigations of water contamination of the source water of the Danjiangkou reservoir with organic micro-pollutants have been limited. This study was conducted to identify and rank organic contaminants that pose risks in the Danjiangkou reservoir. To this end, the Chemical Hazard Evaluation and Manage- ment Strategies （CHEMS-1） approach was adapted to integrate the deconvolution technology of qualitative identifying contaminants for site-specific environmental matrices. The samples were screened for the presence of 1093 contaminants using deconvolution technologies and the hazard values of the identified contaminants were calculated using the adapted CHEMS-1 approach accord- ing to their hazardous properties and occurrence in source water. The results showed that 46 contaminants from 1093 targets were present in Danjiangkou water, 23 of which appeared at frequencies higher than 50%, and 15 of which were identified as priorities. Over half （53%） of the high- ranked contaminants were polycyclic aromatic hydrocar- bons （PAHs）, with chrysene ranked highest on the list. Health risk assessment of the top-ranked PAHs was conducted and revealed that cancer risks of PAHs detected in the source water of Danjiangkou to different populations ranged from 10-7 to 104, indicating a low cancer risk to consumers. The results of this study indicated that the adapted CHEMS-1 approach was feasible for site-specific screening of organic contaminants to identify and rank potential priority pollutants.     

Electrochemical treatment of wastewater to remove contaminants from the production and disposal of plastics: a review

Wastewater is major source of contaminants originating from the production, usage, and disposal of plastic materials. Due to their poor biodegradability of these contaminants in municipal wastewater treatment plants, additional advanced oxidation processes such as electrochemical treatments have been developed to improve the standard biological treatment. Here we review the applications of electrochemical treatments of wastewater for the removal of the following plastic contaminants: bisphenol A, phthalic acid esters, and benzotriazoles. We present the effectiveness of treatment in terms of contaminant removal and mineralization; the identification of transformation products; toxicity assessment; and process energy requirements. In the present review, we have focused on the applications of electrochemical treatments of wastewater for the removal of three important groups of contaminants originating mainly from plastics: bisphenol A, phthalic acid esters, and benzotriazoles. The review focuses on the research of electrochemical treatments for these contaminants from the last five years. The papers are assessed from the point of i) effectiveness of treatment in terms of contaminant removal and mineralization; ii) identification of transformation products; iii) toxicity assessment; iv) processes’ energy requirements. Electrochemical treatments were confirmed to be a viable option for the removal of selected contaminants from wastewater.

     

Occurrence,abundance, and distribution of microplastics pollution: an evidence in surface tropical water of Klang River estuary,Malaysia

Environmental Geochemistry and Health - Microplastics have been considered as contaminants of emerging concern due to ubiquity in the environment; however, the occurrence of microplastics in river...     

新型污染物及其生态和环境健康效应

近年来,随着现代分析手段的改进和发展,各种污染物检测能力的提高,以及新的毒作用模式的发现、新合成化合物的制造和使用等,一些物质成为广受国内外关注的新型污染物.新型污染物已在世界范围内对环境和生态系统造成了污染,对生态系统中包括人类在内的各种生物均构成了潜在的危害.目前,人们关注较多的新型污染物主要有全氟有机化合物、人用与兽用药物、饮用水消毒副产物、遮光剂/滤紫外线剂、人造纳米材料、汽油添加剂、溴化阻燃剂等.论文在总结国内外相关研究基础上,对一些重点新型污染物的生态效应及其潜在健康影响进行了简要综述,为我国开展这方面的研究提供了一定的参考.     

巢湖生态系统中微量有机污染物的研究进展

本文综述了目前巢湖生态系统中微量有机污染物研究的主要进展。巢湖微量有机污染物研究起步较晚,但发展较快。目前已研究的微量有机污染物包括有机氯农药、多氯联苯、多环芳烃、多溴联苯醚、邻苯二甲酸酯、全氟烷基酸类物质、四溴双酚A、抗生素和有机磷农药。研究内容主要包括水、大气、降尘、沉积物、悬浮物、水生生物等多介质分布、来源解析、跨界面迁移、归趋模拟与风险评估等方面。期望本文的综述,可以为巢湖微量有机污染物风险管理和水质改善提供重要决策支撑,对于在其他湖泊开展此类研究有所裨益。     

Alligators, contaminants and steroid hormones.

Steroids are essential for successful reproduction in all vertebrate species. Over the last several decades, extensive research has indicated that exposure to various environmental pollutants can disrupt steroidogenesis and steroid signaling. Although steroidogenesis is regulated by the hypothalamic-pituitary axis, it is also modified by various paracrine and autocrine factors. Furthermore, the classical two-cell model of steroidogenesis in the developing ovarian follicle, involving the granulosa and theca cells in mammals, may not be universal. Instead, birds and probably reptiles use the two thecal compartments (theca interna and theca externa) as sites of steroid production. We have documented that embryonic or juvenile exposure to a complex mixture of contaminants from agricultural and storm water runoff leads to altered steroid hormone profiles in American alligators. Our observations suggest that alterations in plasma steroid hormone concentrations are due in part to altered gene expression, modified hepatic biotransformation and altered gonadal steroidogenesis. Future studies must examine the interplay between endocrine and paracrine regulation in the development and expression of gonadal steroidogenesis in individuals exposed to endocrine disrupting contaminants at various life stages if we are to fully understand potential detrimental outcomes.     

Water Quality and Pollution in the Hunchun Basin, China

Chemical properties and pollution of water resources were studied in the Hunchun basin, which is located in northeast China and borders directly North Korea and Russia along the Tumen river. Water quality was characterised according to its major constituents and geological features. Ground waters could generally be grouped into (Ca+Mg)-HCO₃ type and (Ca+Mg)-(SO₃+Cl) type in first and the second terrace areas, respectively. The mixing of these two types depends on the local conditions, such as pumping or permeability variations.Hunchun city is a pollution source for local water resources due to its uncontrolled sewage and urban discharge. In a previous study of the southwestern part of the Hunchun basin, groundwater contamination by Fe, Mn and NO₃-N was reported. In addition, this study identified Cd and F as prevailing contaminants in the water resources. Pollution of water resources by these contaminants appeared to be affected by the application of fertilisers, irrigation practice, variation of aquifer characteristics, solubility of mineral phases, and discharge of domestic sewage. Wide distribution and high levels of Cd and F in surface- and ground waters could pose significant problems if they are utilised as major water supply sources.