铅的污染危害及天然产物防治锅中毒

本文从铅污染的生物环境化、低浓度铅污染对儿童发育和智力的阻碍、传统驱铅剂存在的问题论述了探索高效、安全无毒副作用驱铅剂对防治环境铅污染慢性中毒的重要性,介绍了国内外利用天然产物防治铅中毒的研究概况及进展,指出利用天然产物防治铅中毒是一项很有意义的探索方向。     

铅的污染危害及天然产物防治铅中毒

本文从铅污染的生活环境化、低浓度环境铅污染对儿童发育和智力的阻碍、传统驱铅剂存在的问题论述了探索高效、安全、无毒副作用驱铅剂对防治环境铅污染慢性中毒的重要性 ,介绍了国内外利用天然产物防治铅中毒的研究概况及进展 ,指出利用天然产物防治铅中毒是一项很有意义的探索方向。     

成都市幼儿体铅水平与环境铅污染的关系

本文检测了成都市 50 1名 3～ 6岁儿童的发铅和血铅水平。发铅平均含量为 17 2 9± 9 70 μg/ g ,血铅平均浓度为 0 59± 0 33μmol/L( 12 3 81± 68 95μg/L)。 60 3%的儿童血铅浓度≥ 0 4 8μmol/L ( 10 0 μg/L) ;3 0 %的儿童血铅浓度≥ 1 4 4 μmol/L( 30 0 μg/L)。发铅与血铅无直线相关关系。市区儿童的发铅和血铅水平显著高于郊区儿童。大气铅测定显示市区铅污染重于郊区。讨论了铅污染的主要来源和儿童铅中毒的预防对策研究。     

环保局长为何难当?

2006年,中国环境形势更为严峻。全年共发生严重环境污染事故161起,平均每两天一起。甘肃徽县铅污染,300多名儿童铅中毒;湖南岳阳砷污染,8万多居     

沈阳市城区大气污染对儿童呼吸系统影响的定量评估

以国际上近年来通用的危险度评价方法为基础，结合大气污染物每增高一单位对儿童呼吸系统健康造成的损失，综合定量评价了沈阳市城区大气污染物对儿童呼吸系统的影响。结果表明：2004年沈阳市皇姑区采暖期大气中PN10、SO2和NOx污染造成儿童上呼吸道感染患病率分别增加0．899％、0．657％和0．536％，儿童气管炎患病率分别增加0．039％、0．047％和0．053％，儿童肺炎患病率分别增加0．069％、0．058％和0．054％。因此，沈阳市采暖期大气PN10、SO2、NOx污染对儿童呼吸系统造成了一定的影响，并导致了其相应疾病患病人数的增加。     

成都市的环境铅水平以及对儿童体铅影响研究

本文介绍了成都地区的大气、食物、自来水和土壤的铅水平，也测试了塑料袋可溶性铅含量，并估算了成都市的主要环境物质对儿童身体铅贡献。在目前条件下，市区幼儿每天从大气吸入铅14．70μg；从食物和自来水分别摄入铅32．4μg和6．56μg，合计一天共进入幼儿身体铅53．8μg，表明成都市环境污染严重，对儿童健康有较大威胁。本文还讲座了环境中铅的主要来源以及孕妇吸入铅对胎儿的健康危害。     

TOA-MIBK萃取火焰原子吸收法同时测定土壤及蔬菜中铅镉

用氢氟酸、硝酸、高氯酸消化土壤样品，干灰化法消解蔬菜样品，用相对TOA-MIBK系统萃取，火焰原子吸收光谱法在同一条件下测定土壤、蔬菜中的铅、镉。在选定条件下，测得土壤铅、镉的相对标准偏差分别为2．3％～4．4％和3．0％～4.3％，蔬菜铅、镉的相对标准偏差分别为2．9％～4．5％和2．6％～4．5％；土壤铅、镉的回收率分别为96％～104％和95％～101％，蔬菜铅、镉的回收率分别为93％～102％92％104％。由测定结果得出离公路越近，蔬菜、土壤铅、镉含量越高。     

长春市土壤铅污染及其对策

重金属铅分布广,有蓄积性,被认为是最严重的环境污染物之一。铅能对人体和其它动物的组织器官造成不同程度的危害。每年人为排入环境中的铅多达150万吨,汽车排放的烷基铅有40－50万吨,铅污染的主要来源是汽油中的防爆添加剂,这些错随着汽车运行排放扩散,50－93％沉降在交通干线两侧的植物和土壤上,使植物和土壤中的铅含量达到几十至数百mg／kg。我国城市交通运输业的发展加速了公路两侧的铅污染。铅在土壤中容易积累,能通过食物链富集并不易被净化,对生物、自然生态、农业生产都有潜在危害,进而影响到社会经济的发展。因此,铅污…     

宁波市鄞州区农业土壤重金属含量变化及评价

为发展无公害农产品基地提供科学依据，2005年对浙江省宁波市鄞州区100个农业土壤样品中重金属含量进行了测定和评价。结果表明：耕层全砷、镉、铬、汞和铅的平均含量分别为8．1mg·kg^-1,0．163mg·kg^-1、100．1mg·kg^-1、0．257mg·kg^-1和3．6mg·kg^-1，与1983年宁波市的耕层土壤背景值相比，分别增加了12．5％、32．5％、61．2％、0．8％和55．2％，土壤已受到镉、铅和汞的轻微污染，而汞的污染已得到遏制。从总体上来说，鄞州区农业土壤环境质量良好，区内有98个点（占总样点数的98％）符合无公害农产品产地土壤环境质量要求，但有2个点（占总样点数的2％）分别受到镉和汞的污染。     

关注留守儿童——留守儿童：他们的未来不容忽视

全国妇联近日发布的研究报告显示，中国有农村留守儿童6102．55万，占农村儿童的37．7％，占全国儿童的21．88％，数量还在迅速地膨胀中，这是一个亟须社会各界都来关注的群体。     

Recycling of spent lead/acid batteries: the case of Greece

In this study, the application of modern recycling technologies in accordance with the European and Greek legislation, aiming at the recovery of lead, polypropylene and sulfuric acid from spent lead (Pb)/acid batteries, is presented. The present state of their disposal and exploitation is also depicted. The international situation is reviewed, the general trends are marked and the main technologies related to lead/acid battery treatment are reported. General recommendations are given regarding the collection of spent batteries and the installation of a recycling plant in Greece. A sensitivity analysis is carried out in order to define the most significant parameters affecting the viability of a recycling scheme. The present study proves that a possible installation of a Pb/acid batteries recycling process unit, treating 17 000 t/year (estimated total quantity) and situated in the industrial area of the greater Athens region, seems to be economically profitable. The already existing operation of small-scale battery recycling plants, common in small countries, should be discouraged as they demonstrate a rather not environmentally acceptable recycling operation.     

Technological improvements in automotive battery recycling

Recycling of automotive batteries for the recovery of secondary lead is extremely important in Brazil, for the country does not possess large reserves of this metal. Lead is one of the most widely used metals in the world, but it is highly toxic, posing risks for humans and for the environment if not utilized or treated adequately. Industrial waste containing lead in Brazil are classified by the Brazilian Residue Code (NBR—10004:2004) as hazardous. The lead recycling process employed by the recycling industry in Brazil is the pyrometallurgical process in a rotary furnace. This process consists of four stages: (1) grinding of the battery to separate plastic, electrolyte and lead plates; (2) lead reduction in a rotary furnace; (3) separation of metallic lead from slag; and (4) refining of recycled lead. The purpose of this work is to propose process improvements aimed primarily at increasing production output by reducing the loss of lead in slag and particulates, thereby providing a healthier work environment in line with Brazilian environmental and labor laws.     

Soil lead contamination at child day care centers in the greater Cincinnati area

Lead concentrations were determined for soil samples collected at 37 child day care centers located within the greater Cincinnati area. Soil samples were collected within 1.5 m of the exterior walls and throughout the remainder of the outdoor playgrounds of each of the child day care facilities. The soil lead concentrations were utilized as indicators of lead contamination from vehicle emissions and lead based paints. Mean lead concentrations were determined through Inductively Coupled Plasma-Mass Spectrometry. Soil lead concentrations were significantly higher within 1.5 m of the exterior walls than the rest of the outdoor play areas of the child day care centers (P < .05). There was a highly significant association between higher soil lead concentrations for child day care centers built prior to 1980 (P < .01). It was also found that a highly significant association exists between higher soil lead concentrations for child day care centers located within 2.5 km of the nearest interstate highway (P < .01). The findings of this research point to a clear need for concern about lead contamination at child day care centers and other facilities that large numbers of children frequent on a daily basis.     

Roadside dusts and soils contamination in Cincinnati,Ohio, USA

Roadside dusts and soils were collected from various nonindustrial districts in Cincinnati, Ohio, USA, and analyzed for lead and copper contents. Results showed that the recent lead phase-down action has reduced the level of lead, but the concentrations of both metals are still higher than the background levels for normal soil. Elevated concentrations of copper in heavily traveled highways were noted, suggesting that much of the copper pollutants is probably of automotive origin. The concentration of lead was found to vary with housing age, and higher levels of contamination in the older neighborhoods were observed. This result is probably ascribable to the accumulation of residues from leaded gasoline and lead-based paint in the past and the use of coal fire for space heating in older houses.     

铅蓄电池厂铅污染土壤清洗剂的筛选及清洗结果研究

为探索不同清洗剂对铅蓄电池厂区内铅污染土壤的去除效果及铅在不同粒径土壤清洗过程中的行为,本研究通过设定清洗剂的浓度梯度,对土样粒径分级、设定清洗时间等方法进行研究。结果显示EDTA和EDDS对铅具有最佳去除率(B点土107.19%和96.49%);盐酸对A点土最佳铅去除率为49.57%,B点、C点土在99.03%和89.93%;柠檬酸对3点位土的铅去除率最大为39.51%;鼠李糖脂对3份土铅去除率均低于10%。EDTA和EDDS在高浓度铅的去除中表现优势;柠檬酸适合去除中低浓度铅;盐酸的使用需考虑土壤本身情况。粗沙粒和细沙粒中的铅去除率高,粉粘粒的铅去除率低;最佳清洗时长为240min。此外,土壤本身理化性质对清洗剂效果的发挥有影响,清洗剂浓度过高可能降低清洗效率。该研究可为铅污染土壤清洗技术提供科学依据。     

Ecotoxicity assessment of slag generated in the process of recycling lead from waste batteries

The aim of this study was to evaluate the possible toxicity of the leachate produced by the residues generated in the process of recycling lead from waste batteries. These residues are slag, which once formed, is characterised by its content in ferrous sulphide, sodium carbonate as well as residual coke from the process. It also contains, as minor components, lead and other heavy metals. The slag was stored and watered periodically over a period of 6 months, its composition changing until finally becoming inert, with no exothermal activity. The slag was leached, and its ecotoxicity was determined by means of the bioluminescence test, along with its content in heavy metals. The results obtained indicate a greater degree of toxicity in the residues with a shorter storage period than the established one, and which were therefore still in the phase of decomposition. However, in the samples taken on completing 6 months of storage, the EC₅₀ value of the leachate was found to be higher than 3000 mg/l. Hence, a storage period under suitable environmental conditions which leads to inactivity of the residue as well as a decrease in its ecotoxicity, is considered absolutely essential. At the same time, a direct relationship was observed between the lead content and the ecotoxicity value.     

Metal Contamination in the Republic of Armenia

/ Air, soil, and water samples were collected throughout the Republic of Armenia both before and after its independence from the Soviet Union in 1991. Reported analyses of those samples indicated that levels of several trace metal concentrations (Ag, Cd, Cr, Cu, Mo, Ni, Pb, Ti, and Zn) exceeded the maximum allowable concentrations established by the former Soviet Union (FSU) and subsequently adopted by Armenia. Although industrial production has declined by more than 80% since the 1980s, the economy is improving and there is potential for a significant increase in the generation of industrial metal emissions. These include automobile emissions, which are now considered to be the primary source of atmospheric lead. Historically, the Soviet Union did not strictly enforce environmental standards, and Armenia is now faced with the resulting environmental problems and the associated risks to public health. Since some trace metal concentrations may be at or near potentially toxic levels, there is a need to accurately assess the extent of metal contamination in order to devise cleanup plans and develop long-term environmental protection and public health strategies in Armenia.     

Leachability of printed wire boards containing leaded and lead-free solder

Due to environmental concerns and regulatory initiatives, electronics manufacturers are replacing the tin/lead solder commonly used on printed wire boards (PWBs) with alternative solders. To determine the potential waste management impacts of the alternative solders versus the tin/lead solder, two leaching tests on PWBs manufactured with five alternative types of solder were performed: the toxicity characteristic leaching procedure (TCLP) and the synthetic precipitation leaching procedure (SPLP). These tests are commonly used in the US regulatory community to assess pollutant leachability in different disposal scenarios. The article discusses the application and limitations of these tests. The five types of solders investigated were 63Sn/37Pb, 99.3Sn/0.7Cu, 95.5Sn/4Ag/0.5 Cu, 96Sn/2.5Ag/1Bi/0.5Cu, and 42Sn/1Ag/57Bi. The leaching tests were conducted on four PWB sections, each with a unique configuration and solder density. The largest lead concentrations were observed from the PWBs containing Sn/Pb solder, with concentrations exceeding the hazardous waste toxicity characteristic (TC) in TCLP leachates. Silver, the other regulated element used in the solders, was rarely detected, with none of the samples exceeding the TC limit for silver. High copper concentrations were observed and were determined to result from the PWB itself, not from the copper-containing solders.     

Kinetic research on the sorption of aqueous lead by synthetic carbonate hydroxyapatite

The sorption of aqueous lead on carbonate-hydroxyapatite (CHAp) is a complicated non-homogeneous solid/water reaction, which from the kinetic point of view has two stages. In the first stage, the reaction rate is so fast and the kinetic pathway so intricate that further research is required. In the second stage, the reaction rate slows down and the reaction process follows that of a first-order kinetic equation. Experimental results show that the relationship between the reaction rate constant k(1) and temperature T agrees with the Arrhenius equation, and that the activation energy of sorption (E(a)) is 11.93 kJ/mol and the frequency factor (A) is 2.51/s. The reaction rate constant k(1) increases with the Pb(2+) initial concentration and decreasing pH, but with increasing CHAp dosage. X-ray diffraction (XRD), scanning electron microscopy with energy dispersion spectrum (SEM-EDS) and toxicity characteristic leaching procedure (TCLP) tests indicate that the main sorption mechanism is dissolution-precipitation, in conjunction with surface sorption.     

Identifying Potential Impact of Lead Contamination Using a Geographic Information System

/ The main objective of this research was to identify the potential hazards associated with lead contami-nation from fixed sources in the city of Tijuana. An exploratory model is presented that describes the potential polluting sources as well as the exposed universe. The results of the analysis provide a clear picture of the geographic distribution of hazards areas for potential lead pollution in Tijuana. The findings are indicative of the dramatic consequences of rapid industrialization and urbanization in a city where there have not been significant planning efforts to mitigate the negative effects of this growth. The approach followed helps to narrow the universe of potential pollution sources, which can help to direct attention, research priorities, and resources to the most critical areas.KEY WORDS: Lead contamination; Industrial hazards; GIS; Tijuana; Mexico