雄黄矿区不同砷污染土壤中微生物群落结构及碳源利用特征

土壤砷污染是我国乃至世界范围内比较严重的环境问题.有关砷污染的生态毒理效应有很多研究,但对砷污染土壤中微生物群落的关注相对较少.本文以我国湖南省石门县雄黄矿地区长期砷污染土壤为例,采用PLFA及BIOLOG微平板技术考察了7个砷(As)污染程度不同的样点以及一个对照样点土壤微生物群落结构及碳源利用特征.结果发现,雄黄矿区存在多种重金属复合污染,除As含量较高以外,镉(Cd)和镍(Ni)的含量也超过了国家土壤环境质量三级标准.雄黄矿区土壤微生物的群落结构受到土壤有机碳(SOC)、有效磷(AP)、p H以及镁(Mg)、Cd、铁(Fe)、铜(Cu)含量的显著影响.各样点土壤微生物群落均以细菌为主,占微生物总量的71.54%~80.66%,真菌次之,放线菌最少.雄黄矿区土壤中的有效砷对微生物造成了较严重的胁迫.严重砷污染降低了微生物对于碳源利用的多样性以及均匀度.各样点微生物对于碳源的利用也表现出明显的差异.31种碳源中微生物利用较多的只有7类,分别属于糖类、胺类、羧酸类与多聚物,并且以糖类为主.     

New insights into disruption of iron homeostasis by environmental pollutants

Among the numerous health conditions environmental pollutants can cause, chronic exposure to pollutants including persistent organic pollutants (POPs) and heavy metals has been shown to disturb a specific biological homeostatic process, the iron metabolism in human body. Disorders of iron metabolism are among the common diseases of humans and encompass a broad spectrum of diseases with different clinical manifestations, ranging from anemia to iron overload, and possibly to neurodegenerative diseases and cancer. Hepcidin–ferroportin (FPN) signaling is one of the key mechanisms responsible for iron supply, utilization, recycling, and storage, and recent studies demonstrated that exposure to environmental pollutants including POPs and heavy metals could lead to disruption of the hepcidin–FPN axis along with disordered systemic iron homeostasis and diseases. This article introduces and highlights the accompanying review article by Drs. Xu and Liu in this journal, which elaborates in detail the adverse effects of environmental pollutants on iron metabolism, and the mechanisms responsible for these toxicological outcomes. It also points out the knowledge gaps still existing in this subject matter. Research that will fill these gaps will improve our understanding of the issue and provide useful information to prevent or treat diseases induced by environmental pollutants.     

Pollution levels and characteristics of phthalate esters in indoor air in hospitals

The concentrations of phthalate esters(PAEs) in Chinese hospitals were investigated by simultaneously determining concentrations of gas- and particle-phase PAEs. PAEs were detected in two third-class first-grade hospitals, two second-class first-grade hospitals, and a community health service center. Hospital drugstores had the highest concentration(24.19 μg/m3), which was 1.54 times that of newly decorated houses. The second highest concentration was found in the transfusion rooms, averaging 21.89 μg/m3; this was followed by the concentrations of PAEs in the nurse's workstations, the wards, and the doctor's offices, with mean concentrations of 20.66, 20.0, and 16.92 μg/m3, respectively. The lowest concentrations were found in the hallways(16.30 μg/m3). Of the six different kinds of PAEs found, major pollutants included diethyl phthalates, dibutyl phthalates, butylbenzyl phthalates and di(2-ethylhexyl) phthalates, comprising more than 80% of all PAEs present.Meanwhile, a comparison between different wards showed that PAE concentrations in the maternity wards were 1.63 times higher than in the main wards. Based on known health hazards, our results suggest that the PAEs seriously influence the health of the pregnant women and babies; therefore, it is of great importance to take the phthalate concentrations in hospitals into consideration. In addition, hospital indoor air was more seriously contaminated than the air of newly decorated houses.     

噪声污染侵权责任中“噪声污染”的界定

判定是否承担噪声污染侵权责任首先是对噪声污染的概念的界定,现行法律对该概念的界定主要采用“超标+干扰”的主客观相结合要件,实践中出现了扰民但噪声不超标的情况,由于不符合“环境噪声污染”概念而难以得到救济.对噪声污染概念的重构需要考虑到行政法中和侵权法中该概念的不同,其蕴含的价值区别.参考国外立法并结合我国实际应将超过忍受限度作为对噪声污染概念界定的标准之一,在保护人身的同时将对财产的保护也纳入保护范围之内.在环境噪声污染侵权中,法院在适用法律裁判案件时,不应运用《环境噪声污染防治法》中关于环境噪声污染概念的界定.     

城市空气污染影响因素的灰色斜率关联度分析研究

城市空气污染严重影响着城市的发展和人民的健康,为了研究城市空气污染的影响因素对于污染的影响程度和类型,采用了灰色系统理论中灰色关联分析方法的斜率关联度模型.以广州、西安和乌鲁木齐为研究对象,选取了几个具有典型的空气污染因素.结果表明:对于这三个城市而言,燃煤都是空气污染的最主要污染因素,而对于不同的城市,其他污染因素对于不同污染物有着不同的影响,在污染治理的时候要分析城市具体所存在的首要污染物以对症下药.     

桂林市公共场所空气污染的检测与分析

采用甲醛检测仪、有机气体检测仪等测试分析了桂林市宾馆、商场、候车室、家具城、文化娱乐场等公共场所的甲醛和TVOC浓度。结果显示:候车室和文化娱乐场所的甲醛、TVOC合格率均为100%;宾馆、商场、家具城的TVOC合格率分别为98.7%、98.9%、95.0%,甲醛合格率分别为78.8%、91.1%、85.0%;皮革制品、家具板材等为主要的甲醛和TVOC污染源。     

某农药厂废弃场地土壤中甲拌磷垂向分布特征

为了解废弃农药厂土壤中甲拌磷的垂向分布特征,在前期表层土壤筛查的基础上,进一步在原甲拌磷生产车间开展了钻孔取样工作,布置了3个钻孔,钻孔深度43.0、41.0和45.0m,根据土壤颜色、岩性、电导率和pH的变化,共采集土壤样品39个,利用高效液相色谱仪对土壤中的甲拌磷进行了定量分析,同时测试了总有机碳、阳离子交换量、土壤粘粒含量、土壤含水率和温度等土壤的理化性质参数。测试结果显示,甲拌磷主要富集在表层土壤中,随着深度的增加,甲拌磷含量逐渐降低。根据相关性分析,土壤中甲拌磷含量和总有机碳含量有着显著的相关性,R分别为0.767、0.893和0.917,这表明土壤总有机碳含量对甲拌磷垂向分布有着非常重要的影响。     

外源有机酸添加对风化煤矸石污染释放及重金属有效性的影响

为评价不同类型有机酸对风化煤矸石污染释放的影响,通过在风化煤矸石中添加不同种类的外源有机酸(腐殖酸、柠檬酸、草酸、水杨酸)进行处理,分析稳定7d后煤矸石浸出液的特征污染组分及TCLP提取态重金属含量。结果表明:对照处理组的风化煤矸石浸出液具有典型的酸性矿山废水特征。添加少量柠檬酸、草酸和水杨酸能显著(p0.05)降低风化煤矸石浸出液的pH和Eh值、明显增加浸出液的盐度、亚铁、总铁和硫酸盐含量,然而腐殖酸处理对浸出液pH、EC、Eh无明显影响,且可降低浸出液硫酸盐含量。少量外源有机酸添加均能不同程度促进风化煤矸石中Fe、Mn、Cu、Zn元素溶出,其中水杨酸处理对4种金属元素的溶出量较大。然而4种外源有机酸处理则能有效抑制Pb溶出,其中柠檬酸、水杨酸处理抑制效果最明显。有机酸添加对风化煤矸石的重金属有效性影响表现为4种外源有机酸处理均能明显增加风化煤矸石中Mn元素的有效性,降低Zn元素的有效性,但对Fe元素的有效性影响不明显。4种外源有机酸添加对煤矸石中Cu元素有效性具有不同程度的影响,其中腐殖酸、草酸处理能明显降低Cu元素有效性,而柠檬酸和水杨酸处理则明显增加Cu的有效性。     

城市大气污染治理方法研究——城市新风系统

城市大气污染治理研究多年来未见突破,为了解决城市大气污染给人们生活带来的危害,利用提高生态修复主体利用率的方法,研究出一种新的城市大气污染治理方法——“城市新风系统”,这种方法理论上可以快速有效改善城市区域内大气环境.该研究以南京为例进行模拟计算,并建立了理论模型的雏形.理论模型预期可在数周内改善城市大气环境,并通过污染与新风总量的科学控制实现范围内的全优环境,这是一个具有可复制性,并有极强的推广意义的方法.     

保定市区采暖与非采暖期环境空气污染状况研究

根据保定大气环境监测数据,对采暖与非采暖期的六项大气污染物浓度变化状况进行了分析.研究结果表明:细颗粒物、可吸入颗粒物、二氧化硫、二氧化氮、一氧化碳五项污染物,采暖期污染物浓度均值明显高于非采暖期,原因是市区集中供热率低,分散燃煤锅炉污染治理水平低,污染物排放量大,采暖期逆温日数多,不利于污染物的垂直扩散.臭氧非采暖期较采暖期明显增加,原因为采暖期过后云层变薄,光照加强,臭氧浓度升高.