多环芳烃的光致毒效应

多环芳烃（ＰＡＨｓ）是一类常见的污染物,过去对其毒性的研究主要集中在生物体内代谢产物的毒效应上。但是近期研究表明紫外光的照射对多环芳烃的毒性具有显著影响,称为ＰＡＨｓ的光致毒效应。本文介绍了多环芳烃在紫外光照射下的急性光致毒作用,致毒作用发生机理及毒性预测的数学模型,同时探讨了ＰＡＨｓ对紫外光致癌性的影响。     

DHDPS的细胞表达、提纯和结晶

ＤＨＤＰＳ是赖氢酸合成通路中第一步的合成酶。将中国春小麦的ＤＨＤＰＳ基因质粒移植入ＲＤＡ８中，得到ＲＤＡ８／ｐＤＢ２６菌株，本研究通过细胞培养、层析提纯和结晶条件的探索，给出了一个较好的技术路线，并为开展义衍射分析蛋白结构创造了条件，通过该研究，对中国春小麦ＤＨＤＰＳ和野种大肠杆菌的ＤＨＤＰＳ差异有了一定的了解，并且对细胞培养的ＭＭ介质处理，ＤＥＡＥ－Ｓｅｐｈａｒｏｓｅ，Ｐｈｅｎｙｌ－Ｓｅｐｈａｒｏｓｅ和ＭｏｎｏＱ层析的方法给出具体实验条仲。酶活的检测和蛋白浓度测定都是采取高灵敏度的方法。结晶的ＳＣｒｅｅｎｉｎｇ条件对于二种ＤＨＤＰＳ有很大的差异。对野种大肠杆茵的ＤＨＤＰＳ，需要表面活性剂Ｎ－ｏｃｔｙｌ－Ｄ－ｇｌｕｃｏｐｙｒａｎｏｓｉｄｅ，ｐＨ１０．０～１０．５，对于中国春小麦一ＤＨＤＰＳ则未找到较好的表面活性剂，ｐＨ６．８～７．６。中国春小麦一ＤＨＤＰＳ晶体培养条件在以往文献中未见报导。     

流动注射氢化物发生法测定水样中痕量砷

报道了用Ｌ－半胱氨酸为预还原剂在低酸度条件下将Ａｓ还原为Ａｓ,用流动注射氢化物发生法测定水样中痕量砷的ＦＩ－ＨＧＡＡＳ法。该方法可用于测定各种不同水体中痕量砷。     

空气中多环芳烃的研究现状

本文比较系统地讨论了空气中多环芳烃（ＰＡＨｓ）的研究现状。重点介绍了空气颗粒物及气相中多环芳烃的采样分析新办法，城市大气及居民室内外空气中多环芳烃的污染状况及其来源，简单介绍了人体接触多环芳烃的水平，指标及空气中多环芳烃的健康风险评价的研究概况。共引文献１２９篇。     

深度氧化工艺处理稀浓度废水

研究运用深度氧化工艺去除废水中的稀浓度有机污染物，讨论了ＡＯＰＳ工艺的优，缺点及其可能的运用；同时考虑了最普通的ＡＯＰｓ工艺的需注意的工程设计问题，研究发现ＡＯＰＳ工艺最适合于目标污染物稀浓度且没有过量其它污染物干扰的情形。     

光催化氧化-混凝工艺处理化工废水

探索了光催化氧化－混凝工艺处理废水的工艺条件,最佳光催化氧化处理条件为ＰＨ＝３,催化剂为铁盐,氧化剂Ｈ２Ｏ２,低压汞灯,光照时间１．５ｈ,废水温度４５℃,温凝剂选用ＰＡＣ和ＰＡＭ（混凝剂的投加量为原水ＣＯＤｃｒ：ＰＡＣ：ＰＡＭ＝７：１．５：０．０１）,混凝ＰＨ６,沉降时间０．５ｈ,在该工艺条件对ＣＯＤｃｒ为１７３－７０１４４ｍｇ／Ｌ的十二烷基苯磺酸钠废水、苯酐废水、富马酸废水、邻苯二甲酸二辛酯废水     

锐颈特与马拉硫磷交替使用对麦穗鱼脑乙酰胆碱酯酶活性恢复的 …

研究了５％锐颈特县浮剂与９５％马拉硫磷文替使用对麦穗鱼（Ｐｓｅｕｄｏｒａｓｂｏｒａ ｐａｒｏａ）乙酰胆碱酯酶（ＡＣｈＥ,ＥＣ３．１．１．７）活性的影响。结果表明,０．２ｍｇ／Ｌ,锐颈物与２ｍｇ／Ｌ马拉硫磷交替使用均影响被抑制的ＡＣｈＥ活性恢复。文中还探讨了研究农药影响对于合理评价农药环境毒性的意义。     

深度氧化技术（AOTs）及其在污水处理中的应用

介绍了深度氧化技术「ＡＯＴｓ」的原理，该技术的关键然团ＯＨ产生的不同及其在不处理工艺中的应用情况，尤其是用于处理垃圾填埋渗滤液的效果。     

菌藻共生体去除废水中砷初探

研究了菌藻共生体对废水中砷的去除效果。研究发现：培养分离所得菌藻共生体中以小球藻为主，此时菌藻共生体积累砷达７．４７ｇ／ｋｇ干重。在引入菌藻共生体并培养１６ｈ后，其对无营养源的含Ａｓ（Ⅲ）、Ａｓ（Ｖ）的废水除砷率达８０％以上，并趋于平衡；含营养源的Ａｓ（Ⅲ）、Ａｓ（Ｖ）的废水中，菌藻共生体对Ａｓ（Ｖ）的去除率大于Ａｓ（Ⅲ），对Ａｓ（Ｖ）去除率超过７０％，但对Ａｓ（Ⅲ）的去除率也在５０％以上，在除砷     

固相萃取技术在水体有机物分析中的应用

本文简述了固相萃取技术（ＳＰＥ）的原理、方法及特点,阐述了ＳＰＥ和气相色谱（ＧＣ）在线与离线两种联用技术应用于水样中有机化合物的分析,并着重介绍了ＳＰＥＧＣ应用于分析水环境中痕量多氯有机化合物,包括多氯联苯化合物（ＰＣＢｓ）和有机氯农药（ＯＣＰｓ）的方法进展情况     

我国环境介质中多环芳烃的分布及其生态风险

持久性有机污染物多环芳烃(PAHs)在我国环境介质中广泛分布,美国EPA规定的16种.优先控制多环芳烃大多在我国大气、水体、沉积物、土壤和生物体内检出.总结了我国环境介质中PAHs污染水平及特点,分析了其存在的环境风险.我国大气中PAHs污染较重,尤其是北方.水体已普遍受PAHs污染,其中部分水体污染严重;沉积物多环芳烃污染大多处于低生态风险水平,但沉积记录研究表明有越来越严重的趋势.我国土壤和生物体PAHs含量较低,污染生态风险较小.部分区域蔬菜中PAHs含量较高,存在不可忽视的生态风险.     

Monitoring of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of southern Luxembourg using XAD-2 resin-based passive samplers

XAD-2 resin-based passive samplers (PAS) with dimensions adapted to 100 mL accelerated solvent extraction cells were used to study the temporal and spatial variations of 17 PAHs on five sites in the atmosphere of southern Luxembourg. This new design allowed extracting the PAS without emptying the resin from the shelter. PAH analyses were done with gas chromatography–tandem mass spectrometry. PAS were deployed for 1 year with varying sampling periodicities, and 16 PAHs were detected with concentrations ranging from 1 ng/PAS for chrysene to 9,727 ng/PAS for naphthalene. The PAS were found adapted to the monitoring of temporal and spatial variations for lightweight PAHs (up to four aromatic rings) though not for heavy PAHs with five aromatic rings or more, as these compounds are preferably in the particle phase of the atmosphere and the amount of these PAHs trapped on the PAS will be too low.     

Chemical characterization and source identification of polycyclic aromatic hydrocarbons in aerosols originating from different sources

To obtain the characteristic factors or signatures of particulate polycyclic aromatic hydrocarbons (PAHs) to help identify the sources of particulate PAHs in the atmosphere, different carbonaceous aerosols were generated by burning different fossil fuels and biomass under different conditions in the laboratory, and the chemical characteristics of 14 PAHs were studied in detail. The results showed that (1) carbonaceous aerosols derived from domestic burning of coal, diesel fuel, and gasoline have much higher concentrations of PAHs than those derived from domestic burning of biomass; (2) carbonaceous aerosols derived from domestic burning of diesel fuel/gasoline have similar PAH components as those derived from high-temperature combustion of diesel fuel/gasoline, although the former have much higher concentrations of PAHs than the latter, suggesting that the burning temperature obviously affects the emitting amount of particulate PAHs, but only slightly influences the PAHs components; and (3) the ratios of benzo[b]fluoranthene/acenaphthylene, benzo[b]fluoranthene/fluorene, dibenzo[a,h]anthracene/acenaphthylene, dibenzo[a,h]anthracene/fluorine, and benzo[b]fluoranthene/benzo[k]fluoranthene in carbonaceous aerosols are sensitively dependent on their sources, indicating that these ratios are suitable for use as characteristic factors or signatures of particulate PAHs in the atmosphere.     

Spatio-Temporal Distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in Atmospheric Air of Tamil Nadu,India, and Human Health Risk Assessment

This study analyzed the seasonal distribution and the possible sources of polycyclic aromatic hydrocarbons (PAHs) in the atmospheric environment of Tamil Nadu, India. Passive air sampling was performed at 32 locations during the period from April 2009 to January 2010, and PAHs were quantified using a gas chromatograph-mass spectrometer. Analysis showed that the concentrations of PAHs were in the range of 5–47.5 ng/m³ with uniform distribution in urban areas in all seasons. Pre-monsoon season showed the highest cumulative concentration of PAHs in both agricultural and coastal areas. Among PAHs, phenanthrene, fluoranthene, and pyrene levels were found to be predominant in all the samples, contributing up to 36%, 35.5%, and 24.5% of total PAHs, respectively. The signature of the PAHs obtained through diagnostic ratio and principal component analysis revealed that diesel emissions was the probable source of PAHs in all locations. Based on Word Health Organization guidelines, the human lung cancer risk due to observed level of PAH concentration (i.e., PAHs exposure) is meager. However, the risk is predicted to be more in the coastal area during summer (18 individuals among 0.1 million people). To the knowledge of these authors, this report is the first on the seasonal analysis of PAHs using passive air sampling in India.     

Oxygenated polycyclic aromatic hydrocarbons in atmospheric particulate matter: Molecular characterization and occurrence

Particulate matter (PM) has become a major research issue receiving increasing attention because of its significant negative impact on human health. There are main indicators that next to the morphological characteristics of the particle, also the chemical composition plays an important role in the adverse health effects of PM. In this context, the rather polar organic fraction of PM is expected to play a major role, and advanced analytical techniques are developed to improve the knowledge on the molecular composition of this fraction. One component class that deserves major attention consists of the oxygenated polycyclic aromatic hydrocarbons (PAHs). Those compounds are considered to be among the key compounds in PM toxicity. This paper presents a comprehensive review focusing on the analysis, fate and behavior of oxygenated PAHs in the atmosphere. The first part of the paper briefly introduces (i) the main sources and atmospheric pathways of oxygenated PAHs, (ii) available physical–chemical properties and (iii) their health effects. The second and main part of this paper gives a thorough discussion on the entire analytical sequence necessary to identify and quantify oxygenated PAHs on atmospheric PM. Special attention is given to critical parameters and innovations related to (i) sampling, (ii) sample preparation including both extraction and clean-up, and (iii) separation and detection. Third, the state-of-the-art knowledge about the atmospheric occurrence of oxygenated PAHs is discussed, including an extended overview of reported concentrations presented as a function of sampling season and geographical location. A clear seasonal effect is observed with the median of the oxygenated PAHs concentrations during winter being a factor of 3–4 higher than during summer. However, the oxygenated PAH/parent PAH ratio is about 20 times higher during summer, indicating the importance of photochemical activity in the atmosphere.     

Use of Benzo[a]pyrene Relative Abundance Ratios to Assess Exposure to Polycyclic Aromatic Hydrocarbons in the Ambient Atmosphere in the Vicinity of a Söderberg Aluminum Smelter

ABSTRACT

The purpose of this study was to investigate the use of benzo[a]pyrene (B[a]P) relative abundance ratios (RARs) to assess exposure to polycyclic aromatic hydrocarbons (PAHs) in the urban atmospheric air in the vicinity of a horizontal stud Söderberg aluminum reduction facility. The B[a]P RARs refer to the concentration of individual PAHs measured in a given sample divided by the concentration of B[a]P found in the same sample. This study compared the B[a]P RARs calculated for the facility stack and three sites near the Söderberg aluminum smelter for three different sampling periods. Interperiod differences were significant for many of the PAHs, and the differences between the stations proved insignificant at p < 0.05. The differences between each individual station and the facility stack were significant for all PAHs. B[a]P RARs increased in value at the stations compared with the stack, indicating that B[a]P may be degraded or removed from the atmosphere at a rate greater than that of the majority of the measured PAHs. It is concluded that B[a]P and B[a]P RARs may be poor markers of exposure to PAHs in the vicinity of this Söderberg aluminum refinery for the entire mixture of PAHs present in the ambient atmosphere.     

Seasonal and spatial occurrence and distribution of atmospheric polycyclic aromatic hydrocarbons (PAHs) in rural and urban areas of the North Chinese Plain

Passive air sampling (PAS) was employed to study the occurrence of gaseous and particle-bound PAHs in the North Chinese Plain. The averaged concentrations of gaseous and particle-bound PAHs were 485 ± 209 ng/m³ and 267 ± 161 ng/m³, respectively. The PAHs concentrations at urban sites were generally higher than those at rural ones with ratios <1.5 in spring, summer and fall, but differences between them were not significant for the wintertime and annually averaged concentrations. This urban-rural distribution pattern was related to the PAHs emission sources. PAHs spatial variation can be partially (49%) explained by emission with a simple linear regression method. Both the gaseous and particle-bound PAHs were highest in winter and lowest in summer, with winter/summer ratios of 1.8 and 8, respectively. Emission strength was the most important factor for the seasonality.     

The fate of PAHs in the carbon black manufacturing process

This study measured PAHs contained in the feedstock oil, carbon black products, and stack flue gas, then the fate of PAHs was assessed from the mass balance point of view for a carbon black manufacturing process. Results show the carbon black manufacturing process would result in the depletion of total-PAHs and the summation of top three carcinogenic PAH species (i.e., BbF+BaP+DBA) up to 98.15% and 99.83%, respectively. The above results suggest that the carbon black manufacturing process would result in not only the decrease of the amount of total-PAHs, but also the carcinogenic potencies of PAHs originally contained in the feedstock oil. Regarding PAHs contained in the carbon black products and stack flue gas, this study suggest they might be resulted mostly from high-temperature pyrolytic process, rather than the PAHs originally contained in the feedstock oil. For the carbon black manufacturing industry, since the soot (i.e., the carbon black) was completely collected as its final product, therefore most of carbon black-bearing PAHs did not directly release to atmosphere. On the other hand, PAHs contained in the stack flue gas were directly exhausted to the atmosphere and thus were assessed in this study. The results show the emission rates for total-PAHs and BbF+BaP+DBA for the stack flue gas were 2.18 kg/day and 1.50 g/day, respectively, which were approximately 25% and 40% of those exhausted from a municipal incinerator with a treatment capacity of 300 metric tons/day. It is concluded that the carbon black manufacturing process might not be a significant PAHs emission source, as compared to the municipal incinerator.     

Source apportionment and source/sink relationships of PAHs in the coastal atmosphere of Chicago and Lake Michigan

Multivariate statistical techniques were used to investigate source apportionment and source/sink relationships for polycyclic aromatic hydrocarbons (PAHs) in the urban and adjacent coastal atmosphere of Chicago/Lake Michigan in 1994–1995. The PAH signatures for the atmospheric particle phase, surface water particle phase and sediments indicate that atmospheric deposition is the major source of PAHs to the sediments and water column particulate phase of Lake Michigan. The PAH signature for the atmospheric gas phase and water dissolved phase indicate an intimate linkage between the lake and its overlying atmosphere. A modified factor analysis-multiple regression model was successfully applied to the source apportionment of atmospheric PAHs (gas+particle). Coal combustion accounted for 48±5% of the ΣPAH concentration in both the urban and adjacent coastal atmosphere, natural gas combustion accounted for 26±2%, coke ovens accounted for 14±3%, and vehicle emissions (gas+diesel) accounted for 9±4%. Each is an identified source category for the region. These results are consistent with the mix of fossil fuel combustion sources and ratios of indicator PAHs.