Human exposure to dioxins through diet in Italy

We have measured the content of polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans (together defined as “dioxins”) in 269 samples of food of animal origin collected through the regional veterinary services, covering the national territory. Quantification of the dioxins was accomplished by isotope dilution method, and toxic equivalents (TEQ) were calculated. The average daily food intake was obtained from two main sources: national data collected by the National Institute of Nutrition, and data from an ongoing cohort study on diet and cancer including 40, 000 Italian subjects.

The mean value of dioxins measured in food of animal origin was 0.144 ± 0.266 pg-TEQ/g (range: 0.003–1.655 pg-TEQ/g). Fish was the item with the highest content. The estimated intake of dioxins with main food items of animal origin is presented. The major contribution to dioxins intake with food comes from cow milk and fish consumption. These results are in agreement with what observed in studies conducted in other countries, such as Germany, Finland, Japan, Spain, and are below the limits set by the European legislation.     

Gas-phase organics in environmental tobacco smoke: 2. Exposure-relevant emission factors and indirect exposures from habitual smoking

Sorption of emitted gas-phase organic compounds onto material surfaces affects environmental tobacco smoke (ETS) composition and exposures indoors. We have introduced a new metric, the exposure relevant emission factor (EREF) that accounts for sorptive uptake and reemission to give the mass of individual ETS constituents available for exposure over a day in which smoking occurs. This paper describes month-long experiments to investigate sorption effects on EREFs and potential ETS exposures under habitual smoking conditions. Cigarettes were smoked in a 50-m³ furnished room over a 3-h period 6–7 days per week, with continuous ventilation at 0.3, 0.6, or 2.1 h⁻¹. Organic gas concentrations were measured every few days over 4-h “smoking”, 10-h “post-smoking” and 10-h “background” periods. Concentration patterns of volatile ETS components including 1,3-butadiene, benzene and acrolein were similar to those calculated for a theoretical non-sorbing tracer, indicating limited sorption. Concentrations of ETS tracers, e.g. 3-ethenylpyridine (3-EP) and nicotine, and lower volatility toxic air contaminants including phenol, cresols, and naphthalene increased as experiments progressed, indicating mass accumulation on surfaces and higher desorption rates. Daily patterns stabilized after week 2, yielding a steady daily cycle of ETS concentrations associated with habitual smoking. EREFs for sorbing compounds were higher under steady cycle versus single-day smoking conditions by 50% for 3-EP, and by 2–3 times for nicotine, phenol, cresols, naphthalene, and methylnaphthalenes. Our results provide relevant information about potential indirect exposures from residual ETS (non-smoker enters room shortly after smoker finishes) and from reemission, and their importance relative to direct exposures (non-smoker present during smoking). Under the conditions examined, indirect exposures accounted for a larger fraction of total potential exposures for sorbing versus non-sorbing compounds, and at lower versus higher ventilation rates. Increasing ventilation can reduce indirect exposures to very low levels for non-sorbing ETS components, but indirect routes accounted for 50% of potential nicotine exposures during non-smoking periods at all ventilation rates.     

Sorption and desorption hysteresis of organic contaminants by kerogen in a sandy aquifer material

Sorption and desorption hysteresis of 1,2-dichlorobenzene, 1,3,5-trichlorobenzene, naphthalene, and phenanthrene were investigated for the Borden aquifer material with total organic carbon of 0.021% and the isolated natural organic matter (NOM). The isolated NOM is a kerogen type of organic matter with relatively low maturation degree and contained many different types of organic matters including vitrinite particles. The modified Freundlich sorption capacities (logK^′_f and logK^′_foc) are very close for the sorption of the four solutes by the isolated NOM and the original sand, respectively. Isotherm non-linearity (n value) and hysteric behaviors are related to solute molecular properties (e.g. K_ow and molecular size). Kerogen encapsulated by inorganic matrices in the original aquifer may not be accessed fully by solutes. The larger the hydrophobic organic chemical (HOC) (hydrophobic organic contaminant) molecule is, the lower accessibility of the HOC to kerogen. This study disputes widely held hypothesis that sorption to mineral surfaces may play a major role in the overall sorption by low TOC (e.g. 0.1% by mass) geomaterials such as Borden sand. It also demonstrates the importance of the condensed NOM domain, even at very low contents, in the sorption and desorption hysteresis of HOCs in groundwater systems.     

Advanced analytical determination of volatile organic compounds (VOC) and other major contaminants in water samples using GC-Ion Trap MS

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Towards sustainable consumption: Predicting the impact of social‐psychological factors on energy conservation intentions in Northern Cyprus

The incessant demand and consumption of energy services among individuals’ is increasing throughout the world. Individuals’ electricity consumption in Northern Cyprus has risen considerably. However, the demand for electrical energy services on the island is heavily reliant on imported fossil fuels. Burning fossil fuels has adverse effects on its environment. Therefore, sustainable energy consumption is required and individuals are targeted for energy conservation to reduce electricity consumption. Against this background, using the Structural Equation Modeling approach, this research incorporates social‐psychological factors; personal norms, positive and negative emotions into the theory of planned behaviour (TPB) model to assess the relationships among the variables, explain their impact on consumers’ electricity conservation intentions and enhance the explanatory power of the model. Data was conveniently obtained from a quantitative sample of 400 electricity consumers. The results indicate that negative emotions have the strongest significant influence on intentions, but personal norms have the least effect on intentions to save electricity. Furthermore, the study revealed that our expanded TPB model can provide improved explanatory power more than the original TPB. Policy implications, limitations and future research are discussed.     

A framework for sustainable supply chain in emerging economies

Sustainable supply chains (SSC) are an essential topic in emerging economies for achieving sustainable development. Because of their rapid economic growth, emerging economies are experiencing both sides of this development: the well‐being enhancement and the environmental impact. However, decision makers and practitioners do not have robust models for managing supply networks that consider the sustainability complexities. This study aims to provide a better understanding of SSC in emerging economies and proposes a generic framework to improve the decision‐making process. Based on a review of the literature, a decision framework for sustainability is proposed. A green sustainable decision concept is also discussed in the SSC literature. This study has implications for scholars, decision makers, and practitioners interested in advancing the SSC field based on an extension of the framework.     

重金属污染河流生态修复区挺水植物对重金属的吸收特性

为了分析比较滇东南选矿区重金属污染河流——小白河生态修复区所种植芦苇和香蒲对重金属的吸收及生态修复效果差异,于2015年4月在小白河西岸野生植物区及东岸生态修复区采集土壤及植物样品,对样品进行烘干、消解,使用电感耦合等离子体发射光谱法测定样品中铅（Pb）、锌（Zn）、铬（Cr）和镍（Ni）这4种重金属的含量,使用原子荧光光谱法测定样品中砷（As）的含量.结果表明:①小白河东岸生态修复区湿地底泥中As和Zn污染最为严重,但东岸底泥中各重金属含量已明显低于西岸,其中芦苇种植区底泥中w（As）和w（Ni）较西岸分别降低了38.82%和50.53%,香蒲种植区底泥中w（As）和w（Ni）较西岸分别降低了13.54%和21.95%.②芦苇对As、Pb、Zn和Pb、Cr以及Cr、Ni这3组重金属的吸收存在显著的协同作用,香蒲对重金属吸收的协同作用表现在As、Zn、Ni和Pb、Cr这2组重金属中,这种重金属吸收协同作用在芦苇中更明显.③芦苇对Cr的生物富集系数（BCF）较高,对Cr的转运系数（TF）为0.80,属于富集型耐受策略,芦苇对Zn和Ni属于根部囤积型耐受策略;香蒲对Pb、Zn、Ni、Cr这4种重金属的BCF较大,TF均接近1,属于富集型耐受策略,对As属于根部囤积型耐受策略.研究显示,芦苇可作为重金属污染河流生态修复区的先锋植物,香蒲的重金属生物富集效率较高,将重金属富集于地上部的能力较强,可考虑将植物分区种植的模式改为间作种植,并定期收割香蒲地上部,以使生态修复区具有更好的重金属修复效果.      

Comparative toxicities of 10 widely used biocides in three freshwater invertebrate species

Owing to their widespread use in wooden products, industrial products, cosmetics, and personal care products, biocides are frequently detected in wastewater and surface water. In this study, I examined the acute toxicities of 10 commonly used biocides, namely methylisothiazolinone, benzisothiazolinone, octylisothiazolinone, dichlorooctylisothiazolinone, iodopropynyl butylcarbamate, triclosan, azoxystrobin, pyraclostrobin, climbazole, and clotrimazole, in the water flea (Daphnia similis), freshwater planarians (Dugesia japonica) and green neon shrimp (Neocaridina denticulata). Among the 10 tested biocides, dichlorooctylisothiazolinone was the most toxic to both D. similis and N. denticulata, whereas pracolstrobin was the most toxic to Du. japonica. By contrast, the least toxic biocides for D. similis, Du. japonica, and N. denticulata were climbazole, iodopropynyl butylcarbamate, and methylisothiazolinone, respectively. The 48-h nominal LC₅₀ values of all the biocides, except for benzisothiazolinone and climbazole, in D. similis were mostly less than 1 mg/L. In addition, the 96-h nominal LC₅₀ values of all the biocides, except for methylisothiazolinone and iodopropynyl butylcarbamate, in Du. japonica was less than 1 mg/L. These results indicate the biocides with low LC₅₀ values are relatively toxic to freshwater organisms.     

The interaction mechanisms of co-existing polybrominated diphenyl ethers and engineered nanoparticles in environmental waters:A critical review

This review focuses on the occurrence and interactions of engineered nanoparticles(ENPs)and brominated flame retardants(BFRs) such as polybrominated diphenyl ethers(PBDEs)in water systems and the generation of highly complex compounds in the environment.The release of ENPs and BFRs(e.g. PBDEs) to aquatic environments during their usage and disposal are summarised together with their key interaction mechanisms. The major interaction mechanisms including electrostatic, van der Waals, hydrophobic, ...     

环境中重金属和有机污染物的物种敏感性分布研究进展

物种敏感性分布法(SSD,Species Sensitivity Distribution)是一种相对于传统评价因子法具有更高置信度的统计学外推方法,在环境质量基准制定及生态风险评价中得到广泛应用。本文对近年来国内外重金属和有机污染物的物种敏感性分布研究成果进行了综述,阐述了在水体、土壤和沉积物等环境介质中应用SSD方法开展生态风险评价的研究现状,从SSD模型选择、毒性数据点筛选等方面对影响SSD模型不确定性的因素进行探讨,并对SSD方法在生态风险评价领域的应用进行了展望。