Pollution characteristics and health risk assessment of benzene homologues in ambient air in the northeastern urban area of Beijing, China

Ambient benzene homologues were measured at a site in the northeastern urban area of Beijing, China, from August 24 to September 4, 2012 by SUMMA canister sampling followed by laboratory determination using cryogenic cold trap pre-concentration-GC-MS/FID, and their health risks were also assessed. Daily total benzene homologues ranged from 0.99 to 49.71 μg/m3with an average of 11.98 μg/m3. Benzene homologues showed higher concentrations in the morning and evening than that at noontime. Comparison with previous studies revealed a trend of decrease for ambient benzene homologues probably due to the efective emission control in Beijing in recent years. Vehicular exhaust was the main source while volatilization of paints and solvents also made substantial contributions. Health risk assessment showed that BTEX(benzene, toluene, ethylbenzene, o-xylene, m-xylene and p-xylene) and styrene had no appreciable adverse non-cancer health risks for the exposed population, while benzene has potential cancer risk of 1.34E-05. Available data from cities in China all implied that benzene imposes relatively higher cancer risk on the exposed populations and therefore strict control measures should be taken to further lower ambient benzene levels in China.     

Congener profiles of PCDDs, PCDFs, and dioxin-like PCBs in the breast milk samples in Tokyo, Japan

Exposure to dioxins has raised much public concern recently. We determined the congeners' distribution of polychlorinated-dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in the breast milk samples collected in Tokyo, Japan. Breast milk was taken from 240 mothers, 30 days after delivery in 1999 and 2000 in Tokyo, Japan. The actual concentration and TEQ concentration of PCDDs (14 congeners), PCDFs (15 congeners), and dl-PCBs (12 congeners), and each congener's contribution to the total TEQ level were calculated. Among all the samples, PCDDs accounted for 34.8%, PCDFs accounted for 23.5%, dl-PCBs accounted for 41.7%, which was also similar in the breast milk from the primiparae and secundiparae. The main contributors to the total TEQ with increasing percentages were 2,3,4,7,8-PeCDF, 1,2,3,7,8-PeCDD and 3,3',4,4',5-PCB (#126), and they accounted for more than 65% of the total TEQ. Detailed congener analysis in breast milk samples is effective to understand dioxin sources.     

ATR-FTIR investigation of the role of phenolic groups in the interaction of some NOM model compounds with aluminum hydroxide

The role of phenolic groups in the interaction of natural organic matter (NOM) with metal hydroxides was investigated with ATR-FTIR spectroscopy and adsorption tests by employing a series of dihydroxybenzoic acids (DHBAs) as the NOM surrogates and aluminum hydroxide as the adsorbent. All DHBAs examined in this study were found to be adsorbed on aluminum hydroxide by forming inner-sphere complexes. Carboxylic groups governed the complexation of DHBAs with aluminum hydroxide at low pH or in cases when the two hydroxyl groups were not adjacent to each other and neither of them was ortho to the carboxylic group. The involvement of the phenolic groups, ortho to another phenolic group or ortho to the carboxylic groups, in the complexation increased with increasing pH as the deprotonation of phenolic groups was easier at higher pH. The presence of phenolic groups increased the electron density of the carboxylic groups and facilitated the inner-sphere complexation of the carboxylic groups with metal hydroxide. The correlation between the pK_a values and the amount of organic acid adsorbed on the aluminum hydroxide revealed that the adsorption of DHBAs at acidic pH was largely dependent on the surface chelate formation rather than on the electronic effect.     

乙烯撑二氨基苯磺酸生产中磺化废酸的处理

对乙烯撑二氨基苯磺酸生产过程中产生的磺化废酸采用浓缩法进行处理,得到的浓硫酸顺生产中使用。废酸浓缩装置的工艺简单,投资少,建设周期短,运行平稳,１年内即可收回投资,经济效益显著。该装置的建成投产,大大改善了周围环境,具有明显的环境效益。     

Pathogen survival in swine manure environments and transmission of human enteric illness--a review

The influence of zoonotic pathogens in animal manure on human health and well-being as a direct or indirect cause of human enteric illness is examined. Available international data are considered, but the study is focused on the developing situation in western Canada, where it is certain there will be further rapid growth in livestock numbers, particularly hogs. Major pathogens considered are Escherichia coli O157:H7, Salmonella, Campylobacter, Yersinia, Cryptosporidium, and Giardia. Canada is now the leading exporter of pork internationally, but recent increases in production contrast with constant domestic levels of pork consumption and declining levels of foodborne illness caused by pork. Effects of increased levels of manure production are not quantifiable in terms of effects on human health. The presence of major pathogens in manure and movement to human food sources and water are considered on the basis of available data. Survival of the organisms in soil, manure, and water indicate significant variability in resistance to environmental challenge that are characteristic of the organisms themselves. Generally, pathogens survived longer in environmental samples at cool temperatures but differences were seen in liquid and solid manure. Based on actual data plus some data extrapolated from cattle manure environments, holding manure at 25 degrees C for 90 d will render it free from the pathogens considered above.     

西南环境移民安置地的生态环境状况

以桂西北环江县肯福环境移民安置示范区为例，对我国西南喀斯特地区，环境移民安置区的气候、地貌、土壤与植被等主要生态因子，进行了调查研究与取样分析，研究表明，环境移民安置地由于地处亚热带季风气候区，具有气候温暖，雨量充沛、日照充足，且雨热同季的特点；地貌破碎，土地以坡地为主，但有一定量可开垦利用的土地；土壤主要为红壤，土壤剖面发育良好，有机质和氮含量相对丰富，磷、钾缺乏，土壤酸度大，土壤质地和结构尚可     

长江以北沿海经济贝类中的麻痹性贝毒

应用小白鼠检测方法，对我国长江以北沿岸的经济贝类进行了麻痹性贝毒检测。采样时间 １９９７年９月２３日￣１２月８日。从鸭绿江口到长江口共调查２０个站位，检测经济贝类１４种，样品３８份，其中只有１份样品检测出麻痹性贝毒（６．４Ｍｎ／ｇ），其余样品均为未检出。     

新疆地区气溶胶对地表太阳辐射的影响初探

为了进一步认识大气气溶胶对气候环境的影响,基于2017年Aqua MODIS C006气溶胶光学厚度（aerosol optical depth,AOD）产品、CERES SSF Aqua MODIS Edition 4A数据集的地表短波辐射以及地面观测太阳辐射数据,对2017年新疆地区AOD和地表太阳辐射年变化进行研究,并以沙尘和人类活动气溶胶丰富的南疆典型地区喀什为代表城市,采用AccuRT辐射传输模式定量化研究晴空时气溶胶对地表短波辐射的影响.结果表明：①地表太阳辐射月均值最大值出现在和田站的5月,为441.62 W·m^-2,最小值出现在乌鲁木齐站点的12月,为37.03 W·m^-2;CERES/SSF地表短波辐射资料与地面观测结果相比,阿克苏站、焉耆站和伊宁站的差距最小,喀什站和若羌站全年存在高估现象,其他站点存在不同程度的高低估现象.②2017年新疆地区AOD格点平均的年均值最小值为0.0175,最大值为0.4610,南疆地区的AOD整体高于北疆地区;2017年AOD格点春夏季的AOD均值分布与全年均值分布特征相似,其中春季的AOD高值区区域面积高于其他季节.③根据AccuRT计算,当AOD由0.05增加为0.56时,四季的地表向下短波总辐射均呈下降趋势,夏季下降幅度最大,由923.02 W·m^-2变化为677.61 W·m^-2,其次为春季和秋季,冬季下降幅度最小.AOD的减少变化导致的地表向下短波总辐射通量、直射辐射通量和散射辐射通量变化敏感度明显高于AOD增加所导致的变化敏感度.     

寒冷地区化粪池的效果评价和探讨

寒冷地区化粪池具有水温低,处理效果差的特点,针对哈尔滨市幸福家园化粪池的水质情况进行了研究,为化粪池的改造和优化提供依据,并对化粪池问题和技术进行探讨。在化粪池前后的检查井处进行取样,每隔1个小时取一个样,总共取24小时,然后对CODtot、CODss、CODcol、CODdis、NH3-N、总氮、总磷、SS、VSS、pH、水温进行测定。水温在14～17度下,平均去除率分别是16.9%、47.2%、26.4%、-49.1%、-39.3%、7.5%、12.4%、59.3%和59.5%,可见,污水的可生化性有明显提高,但是对污染物的去除作用不大。研究结果对于全面评价寒冷地区化粪池的功能特征,进而为化粪池的取舍和改造提供技术的参考依据。     

中小城市发展循环经济大有作为

企业层面开展循环经济试点 2002年,泰兴市率先在企业层面开展循环经济试点工作.经过几年的努力,泰兴的企业在大幅度提升经济和社会效益的同时,环境效益也显著提高.