广州市区县环境竞争力评价研究

近年来环境在城市竞争中的作用日益凸显,城市在经济转型升级的关键时期,迫切需要提升环境竞争力,以优良的环境质量和利用环境资源创造价值的能力来参与国际竞争.而城市的整体环境竞争力是在各区、县环境竞争力的基础上形成的,提升各区(县)环境竞争力有利于提升城市环境竞争力.首先论述了环境竞争力的概念及内容,构建了广州区县环境竞争力评价模型,然后对评价结果进行详细的分析,并提出有关建议.     

ICP-MS法测定环境空气TSP中铬镍铜的不确定度评定研究

对电感耦合等离子体质谱(ICP-MS)法测定环境空气TSP中铬、镍、铜的过程中可能引入的不确定度分量,包括样品采集体积、样品消解、定容体积、标准溶液配制、标准曲线拟合、重复测定等进行分析和评定,并得出扩展不确定度.结果显示,对于铬、镍、铜,样品消解和曲线拟合引入的不确定度最大,其次是重复测定和孔口流量校准器的流量校准,采样器重复性和消解定容的不确定度最小.为ICP-MS法测量环境空气TSP重金属元素的质量控制和不确定度评定提供参考依据.     

浅述职业紧张对员工健康的影响及干预策略

随着医学模式从生物医学模式向生物—心理—社会医学模式的转变,心理社会因素对健康的影响日益加重。文章探讨职业紧张与健康的关系及其可能会给作业员工健康造成的损害和相关干预措施。得出:职业紧张对健康的影响是较长时间内过大的压力所表现出来的累积性反应,其发展过程是缓慢和渐进的,可能会出现高血压、冠心病、中风、睡眠障碍等症状,在日常工作中,有必要采取有针对性的干预措施,其最基本的办法是干预生产活动中的紧张因素,提高作业员工的控制和适应能力,最终达到良性循环。     

Similarities and differences of metal distributions in the tissues of molluscs by using multivariate analyses

Multivariate analysis including correlation, multiple stepwise linear regression, and cluster analyses were applied to investigate the heavy metal concentrations (Cd, Cu, Fe, Ni, Pb, and Zn) in the different parts of bivalves and gastropods. It was also aimed to distinguish statistically the differences between the marine bivalves and the gastropods with regards to the accumulation of heavy metals in the different tissues. The different parts of four species of bivalves and four species of gastropods were obtained and analyzed for heavy metals. The multivariate analyses were then applied on the data. From the multivariate analyses conducted, there were correlations found between the soft tissues of bivalves and gastropods, but none was found between the shells and the soft tissues of most of the molluscs (except for Cerithidea obtusa and Puglina cochlidium). The significant correlations (P < 0.05) found between the soft tissues were further complemented by the multiple stepwise linear regressions where heavy metals in the total soft tissues were influenced by the accumulation in the different types of soft tissues. The present study found that the distributions of heavy metals in the different parts of molluscs were related to their feeding habits and living habitats. The statistical approaches proposed in this study are recommended for use in biomonitoring studies, since multivariate analyses can reduce the cost and time involved in identifying an effective tissue to monitor the heavy metal(s) bioavailability and contamination in tropical coastal waters.     

Decomplexation of Cr(III)-EDTA and simultaneous abatement of total Cr by photo-oxidation: efficiency and in situ reduction of intermediate Cr(VI)

Environmental Science and Pollution Research - Most prevailing processes are incapable of removing Cr(III)-organic complexes efficiently and facing the problem of in-process formation of highly...     

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.