重金属对食品的污染及其危害

铅、砷、汞、镉、锡等有毒重金属通过各种途径污染食品,沿食物链进入人体后,给人体健康带来严重危害.本文综述了几种重金属对食品的污染及其来源,对人体的危害及其预防,以便提高人们的食品安全意识,加强环境保护,维护人体健康.     

Sustainable urban development — the public health dimension

１　Ｓｕｓｔａｉｎａｂｌｅｕｒｂａｎｄｅｖｅｌｏｐｍｅｎｔ—ｔｈｅｐｕｂｌｉｃｈｅａｌｔｈｄｉｍｅｎｓｉｏｎＴｏｗｎｓａｎｄｃｉｔｉｅｓａｒｅｃｕｒｒｅｎｔｌｙｔｈｅｆｏｃｕｓｆｏｒｅｃｏｎｏｍｉｃｐｌａｎｎｉｎｇａｎｄｄｅｖｅｌｏｐｍｅｎｔｉｎＥｕｒｏｐｅａｎｃｏｕｎｔｒｉｅｓ．Ｆｏｒｍｅｒｌｙ，ｐｏｌｉｔｉｃｉａｎｓａｎｄｐｌａｎｎｅｒｓｐｒｉｏｒｉｔｉｚｅｄｉｎｔｅｒｎａｔｉｏｎａｌａｎｄｎａｔｉｏｎａｌｌｅｖｅｌｓ，ｗｉｔｈｍａｃｒｏｅｃｏｎｏｍｉｃｄｅｖｅｌｏｐｍｅｎｔｓｅｅｎａｓｔ…     

工业园区内构建EHS管理体系框架研究

作为地区经济的支撑点,工业园对当地经济、社会、文化等的贡献作用有目共睹.但在中国加入世贸组织后,工业生态问题受到越来越多的重视,我们必须从解决实际问题出发,以储备经济可持续发展动力为着眼点.改变中国工业园的管理模式.为实现以上目标,本文借鉴了工业生态园的概念,并结合环境、健康和安全管理(EHS),为今后中国工业园管理提供了崭新思路.     

Impact of Gold mining on the Environment and Human Health: A Case Study in the Migori Gold Belt, Kenya

The study of gold sites in the Migori Gold Belt, Kenya, revealed that the concentrations of heavy metals, mainly Hg, Pb and As are above acceptable levels. Tailings at the panning sites recorded values of 6.5–510 mg kg^–1 Pb, 0.06–76.0 mg kg^–1 As and 0.46–1920 mg kg^–1 Hg. Stream sediments had values of 3.0–11075 mg kg^–1 Pb, 0.014–1.87 mg kg^–1 As and 0.28–348 mg kg^–1 Hg. The highest metal contamination was recorded in sediments from the Macalder stream (11075 mg kg^–1 Pb), Nairobi mine tailings (76.0 mg kg^–1 As) and Mickey tailings (1920 mg kg^–1 Hg). Mercury has a long residence time in the environment and this makes its emissions from artisan mining a threat to health. Inhaling large amounts of siliceous dust, careless handling of mercury during gold panning and Au/Hg amalgam processing, existence of water logged pits and trenches; and large number of miners sharing poor quality air in the mines are the major causes of health hazards among miners. The amount of mercury used by miners for gold amalgamation during peak mining periods varies from 150 to 200 kg per month. Out of this, about 40% are lost during panning and 60% lost during heating Au/Hg amalgam. The use of pressure burners to weaken the reef is a deadly mining procedure as hot particles of Pb, As and other sulphide minerals burn the body. Burns become septic. This, apparently, leads to death within 2–3 years. On-site training of miners on safe mining practices met with enthusiasm and acceptance. The use of dust masks, air filters and heavy chemical gloves during mining and mineral processing were readily accepted. Miners were thus advised to purchase such protective gear, and to continue using them for the sake of their health. The miners' workshop, which was held at the end of the project is likely to bear fruit. The Migori District Commissioner and other Government officials, including medical officers attended this workshop. As a result of this, the Government is seriously considering setting up a clinic at Masara, which is one of the mining centres in the district. This would improve the health of the mining community.     

Female tree swallows (<Emphasis Type="Italic">Tachycineta bicolor</Emphasis>) increase offspring heterozygosity through extrapair mating

Recent attention has focused on genetic compatibility as an adaptive function for why females engage in extrapair mating. We tested the genetic compatibility hypothesis in tree swallows (Tachycineta bicolor) over five breeding seasons using data from ten microsatellite loci. Tree swallows are socially monogamous passerines exhibiting high levels of extrapair paternity. Overall, we found that 47% of offspring were the result of extrapair fertilizations, and 83% of females produced at least one extrapair offspring. Consistently for all years, extrapair offspring were more heterozygous than their maternal half-siblings, which is in accordance with the genetic compatibility hypothesis. The difference was largely caused by the high heterozygosity of extrapair offspring sired by unknown males, suggesting that females are engaging in extrapair copulations with geographically distant males to increase the likelihood of being inseminated by a more compatible mate. Our findings support the idea that postcopulatory mechanisms are important for females when assessing potential sires for their offspring.     

Air pollution effects on hospital admissions: a statistical analysis of parallel time series

A statistical model for longitudinal count data is used to examine the potential adverse health effects of ambient air pollution. Daily respiratory admissions to 164 acute care hospitals in Ontario are obtained for the period 1983 to 1988. Estimates of ozone levels in the vicinity of each hospital are determined from air pollution monitoring stations maintained by the Ontario Ministry of the Environment. Generalized estimating equation methods are used to make inferences about the regression and overdispersion parameters. The admission data display little evidence of serial correlation and extra Poisson variation. However, admission rates vary considerably among hospitals. This latter source of variation needs to be taken into account in examining the effects of air pollution on respiratory health status.     

Natural pollution caused by the extremely acidic crater lake Kawah Ijen, East Java, Indonesia

Background. Aims and Scope Lakes developing in volcano craters can become highly acidic through the influx of volcanic gases, yielding one of the chemically most extreme natural environments on earth. The Kawah Ijen crater lake in East Java (Indonesia) has a pH 〈 0.3. It is the source of the extremely acid and metal-polluted river Banyupahit (45 km). The lake has a significant impact on the river ecosystem as well as on a densely populated area downstream, where agricultural fields are irrigated with water with a pH between 2.5 and 3.5. The chemistry of the river water seemed to have changed over the past decade and the negative effect in the irrigation area increased. A multidisciplinary approach was used to investigate the altered situation and to get insight in the water chemistry and the hydrological processes influencing these alterations. Moreover, a first investigation of the effects of the low pH on ecosystem health and human health was performed. Methods Water samples were taken at different sites along the river and in the irrigation area. Sampling for macroinvertebrates was performed at the same sites. Samples of soil and crop were taken in the irrigation area. All samples were analysed for metals (using ICP-AES) and other elements, and concentrations were compared to local and international standards. Results and Discussion The river carries a very high load of SO4, NH4, PO4, Cl, F, Fe, Cu, Pb, Zn, Al and other potentially toxic elements. Precipitation and discharge data over the period of 1980 – 2000 clearly show that the precipitation on the Ijen plateau influences water chemistry of the downstream river. Metal concentrations in the river water exceed the concentrations mentioned in Indonesian and international quality guidelines, even in the downstream river and the irrigation area. Some metal concentrations are extremely high, especially iron (up to 1600 mg/l) and aluminium (up to 3000 mg/l). The food-webs in the acidic parts of the river are highly underdeveloped. No invertebrates were present in the extremely acid water and, at pH 2.3, only chironomids were found. This also holds true for the river water with pH 3.3 in the downstream area. Agricultural soils in the irrigation area have a pH of 3.9 compared to a pH of 7.0 for soils irrigated with neutral water. Decreased yields of cultivated crops are probably caused by the use of Al containing acid irrigation water. Increased levels of metals (especially Cd, Co, Ni and Mn) are found in different foodstuffs, but still remain within acceptable ranges. Considering local residents” diets, Cd levels may lead to an increased risk for the human health. Fluoride exposure is of highest concern, with levels in drinking water exceeding guideline values and a lot of local residents suffering from dental fluorosis. Conclusions, Recommendations and Outlook In short, our data indicate that the Ijen crater lake presents a serious threat to the environment as well as human health and agricultural production.     

δC variations in tree rings as an indication of severe changes in the urban air quality

Annual growth rings sampled from three free-standing trees (Platanus hybrida sp.), grew in the metropolitan area of Palermo (Italy) and covering a 118 years time span (1880–1998), have been studied for their ¹³C/¹²C carbon isotope ratios. It has been found that the ¹³C/¹²C tree ring record, during the study time interval, decreased of −3.6‰, from −26.4‰ in 1880 to −30‰ in 1998. Such a progressive depletion has been attributed to the addition of anthropogenic ¹³C depleted carbon dioxide to the local atmosphere. The observed ¹³C/¹²C decrease has been used to infer some possible pathways of atmospheric CO₂ change in the study urban area.     

Distribution and Risk Assessment of Fluoride in Drinking Water in the West Plain Region of Jilin Province, China

The west plain region of Jilin province of northeast China is one of the typical endemic fluorosis areas caused by drinking water for many years. Investigations of hydrogeological and ecoenvironmental conditions as well as endemic fluorosis were conducted in 1998. Results show that the ground water, especially, the water in the unconfined aquifer is the main source of drinking water for local residents. The fluoride concentration in groundwater in the unconfined aquifers is higher than that in the confined aquifer in the west plain of Jilin province. The fluoride concentration in the unconfined aquifer can be used to classify the plain into fluoride deficient area, optimum area and excess area, which trend from west to east. High fluoride (>1.0 mg L(-1)) in drinking water resulted in dental and skeletal fluorosis in local residents (children and pregnant women). There exists a positive correlation between fluoride concentration in the drinking water and the morbidities of endemic fluorosis disease (r1 = 0.781, r2 = 0.872). Health risks associated with fluoride concentration in drinking water are assessed. It has been determined that fluoride concentration in excess of 1.0 mg L(-1) exposes residents to high health risks based on risk identification. The study area is classified into five health risk classes as shown in Figure 4. The risk indexes of this area more than 1.0 are accounted for 68% of the total west plain region.     

环境蛋白组学及污染物分子毒性检测技术

环境蛋白组学是蛋白组学与环境科学交叉融合的新兴学科,研究污染环境与蛋白组之间的相互作用规律与检测技术方法.环境蛋白组学的发展,取决于双向凝胶电泳、质谱、蛋白质芯片和生物信息学等技术的完善与应用.综述环境蛋白组学的主流技术,介绍环境蛋白组学技术在污染物分子毒性检测中的应用,探索污染物与蛋白组之间的相互作用机理,是人体与环境健康科技发展的起步过程.