湖南省三十六湾矿区耕地重金属健康风险评价及生态修复对策

三十六湾矿区是全国第三批“山水林田湖草”生态保护修复工程耕地复垦重点修复试点区。本文基于污染指数法、地积累指数、富集系数和USEPA健康风险评价模型,探究三十六湾矿区土壤重金属的污染特征、农作物重金属累积状况及其对人体健康的危害,提出土壤修复建议,以期为矿区土壤重金属污染防治和管控提供科学依据。结果表明,土壤重金属综合污染指数为中—重度,其风险等级为：Cd>Pb>As>Zn>Hg>Cu>Cr>Ni;农作物Cd全部超标,白菜和萝卜Pb、Cr超标,水稻、白菜和萝卜As超标,白菜Hg超标。农作物对重金属的富集能力为：水稻>白菜>萝卜。食用农产品的非致癌风险Cr>As>Cd>Pb>Hg,成人与儿童的非致癌危害指数分别为1.04和2.11,致癌风险指数分别为1.62×10^-5和3.34×10^-4,显示成人和儿童均有非致癌风险,儿童有致癌风险,且儿童各种风险都大于成人。建议采取工程措施与物理化学法结合、重金属稳定剂-抗逆性植物联合、植物修复、土壤调理-轮作休耕等技术开展区域耕地...     

六安市城区饮用水中氯仿和四氯化碳健康风险初评

目的运用健康风险评价方法定量描述六安市城区饮用水中三氯甲烷和四氯化碳含量,评价其对人体健康产生潜在风险。方法 2014年,根据六安市城区(金安区、裕安区、开发区)人口的聚集程度设置水质监测点,并对监测点的水样进行采集和检测。结果六安市城区饮用水中三氯甲烷、四氯化碳的浓度(中位数)分别为0.035 mg/L和0.0002 mg/L,致癌个人风险为59.3×10~(-6)和1.10×10~(-6),非致癌健康风险值个人健康风险为0.1912和0.0122。结论六安市城区饮用水中三氯甲烷和四氯化碳对人体健康产生的潜在致癌个人风险和非致癌健康风险均在美国环境保护署(US EPA)可以接受的限值之内。     

我国中小水厂三卤甲烷和卤乙酸的健康风险评价

中小水厂供水规模小、技术水平有限,消毒副产物及其对人体健康产生的潜在危害受到了广泛关注。为评价我国中小水厂出厂水中三卤甲烷和卤乙酸对人体健康产生的潜在危害,选取位于珠江流域、长江流域和淮河流域的4家中小水厂(A、B、C和D),于2016年6月、7月、8月、12月和2017年1月、2月采集出厂水水样共48份,检测三卤甲烷(三氯甲烷、二氯一溴甲烷、一氯二溴甲烷、三溴甲烷)和卤乙酸(二氯乙酸、三氯乙酸)含量,并结合美国环境保护署(USEPA)推荐的健康风险评价模型对以经口摄入为暴露途径所引起的健康风险进行评价。4家中小水厂出厂水中三卤甲烷的含量为12.06～47.79μg/L,卤乙酸含量为10.38～47.26μg/L,各水厂出厂水的经口致癌健康风险分别为7.47×10~(-5)、6.88×10~(-5)、6.27×10~(-5)和8.70×10~(-5),非致癌健康风险分别为0.179、0.157、0.177、0.207。4家水厂出厂水中的消毒副产物浓度没有超过国标限值,经口致癌和非致癌健康风险均在USEPA的可接受风险水平。     

北京市政供水中三氯甲烷和四氯化碳含量分析及健康风险评估

目的了解南水北调之后北京市市政水中三氯甲烷和四氯化碳的浓度水平,评估其对人体健康的潜在风险。方法收集了2015—2019年北京市出厂水、末梢水和二次供水中三氯甲烷和四氯化碳的监测数据,利用美国环保局(USEPA)推荐的健康风险评价四步法模型对其进行健康风险评估。结果 4 292件监测水样中,三氯甲烷平均浓度为0.003 00 mg/L,四氯化碳平均浓度为0.000 62 mg/L,两种污染物的合格率均为100%。三氯甲烷和四氯化碳的致癌风险分别为3.23×10~(-6)、1.51×10~(-7);非致癌风险分别为1.04×10~(-2)、5.39×10~(-4)。结论北京市市政水中四氯化碳的健康风险较小,三氯甲烷的健康风险属于可接受范围,但由于南水北调后水质变化较大,仍需要继续监测并提出风险管控措施。     

石家庄市农村饮用水重金属健康风险评价

目的对石家庄市农村饮用水中重金属的健康风险进行评价。方法于2012年枯水期(4月)和丰水期(7月)分别对10个县245个行政村的地下水出厂水进行采集检测,采用美国环保局(USEPA)推荐的健康风险评价模型对地下水中砷、镉、铬、铅和汞经饮水途径所引起的健康风险做初步评价。结果 3种基因有毒物质所引起健康危害的个人年总风险水平为8.44×10-5/年,超过国际辐射防护委员会(ICRP)推荐的最大可接受值(5.0×10-5/年)。铅(8.50×10-10/年)的健康危害的个人年风险水平高于汞(3.23×10-10/年),两者均未超过国际辐射防护委员会(ICRP)推荐的最大可接受值(5.0×10-5/年)。结论石家庄市部分县监测点饮用水中铬可能存在一定的健康风险。     

某市饮用水中10种污染物的健康风险评价

目的评价某市饮用水中砷等10种污染物经饮水途径对人体的健康风险,为饮用水健康风险管理提供理论依据。方法 2017年根据某市市政水厂的供水范围,选择128个监测点开展监测,分别于丰水期和枯水期各采集128份水样,按照《生活饮用水标准检验方法》(GB/T 5750-2006)进行浓度检测。运用环境健康风险评估四步法定量分析我国某市饮用水中As、Se两种类重金属、Cd、Cr(Ⅵ)、Pb、Hg、Cu、Zn等6种重金属及CHCl_3、CCl_4两种有机物的非致癌风险值和致癌风险值。结果某市饮用水中上述十种污染物浓度均符合《生活饮用水卫生标准》(GB 5749-2006)的要求,达标率100%。居民经口摄入自来水非致癌总风险值为0.122,处于可接受范围内;致癌总风险值为2.59×10~(-5),有致癌风险。其中砷的暴露对非致癌风险和致癌风险贡献率均最大,三氯甲烷的致癌风险也高于10~(-6)的可接受风险。末梢水和二次供水中铜的风险值要高于出厂水,锌风险值要低于出厂水;丰水期总致癌风险要高于枯水期;深度处理的水样其非致癌总风险更小。结论某市饮用水中经饮水途径暴露As等10种污染物产生的致癌风险超过可接受风险水平;其中砷的健康风险最高。     

2017年北京市怀柔区大气PM_(2.5)中重金属污染特征及健康风险评价

目的研究怀柔区大气中PM_(2.5)浓度和PM_(2.5)中重金属污染特征及对人体的危害。方法 2017年1月—12月采集怀柔地区环境大气PM_(2.5)样品,共84份样品,用SPSS 23.0对PM_(2.5)及镉(Cd)、六价铬(Cr)、镍(Ni)、锰(Mn)、铅(Pb)等5种重金属元素的浓度特征进行分析,用美国环境保护署健康风险评价模型对重金属元素进行呼吸暴露的非致癌风险值和致癌风险值进行计算,并评价其健康风险。结果怀柔区大气PM_(2.5)年均浓度为46.39μg/m~3,低于我国环境空气质量二级标准(75μg/m~3);重金属浓度高低依次为Pb>Mn>Cr>Ni>Cd,5种重金属的非致癌风险值HQ儿童>成年男性>成年女性,3种重金属的致癌风险值由高到底依次为Ni>Cd>Cr,成年男性的致癌风险最大,其次是成年女性,对儿童的致癌风险相对最小。结论 5种重金属的非致癌风险值HQ均小于1,表明对人体健康影响较小。     

武汉市主城区市政水中三氯甲烷和四氯化碳健康风险评价

目的调查武汉市主城区市政水中三氯甲烷和四氯化碳的含量,评估其对人体健康可能产生的潜在危害。方法在武汉市主城区设立40个市政管网末梢水监测点,每个季度进行采样监测1次,连续监测3 a,利用健康风险评价模型评估三氯甲烷和四氯化碳通过饮水途径可能导致的健康风险。结果 2015—2017年武汉市主城区市政供水中三氯甲烷年平均浓度没有显著性差异(P=0.240),季平均浓度有显著性差异(P<0.05);此外汉阳和汉口地区市政供水中三氯甲烷的质量浓度要高于武昌地区,(P<0.05)。四氯化碳主要集中在2015年一、二季度检出,2016年和2017年检出率较低。2015—2017年武汉市主城区市政水中三氯甲烷、四氯化碳总致癌风险为(1.87×10~(-5)～3.08×10~(-5))/a,其中三氯甲烷致癌风险占总致癌风险值99%左右。结论武汉市主城区市政水中三氯甲烷通过饮水途径产生的健康风险尚可接受,但应引起重视;四氯化碳通过饮水途径产生的健康风险不明显。     

无锡地区出厂水消毒副产物变化趋势及致癌风险研究

目的了解2008—2012年无锡地区出厂水中消毒副产物(DBPs)变化趋势,评估其对成人的致癌风险。方法选取无锡市四家市政供水水厂,于2008—2012年间丰枯水期(8月和2月)采集水样进行监测,监测指标包括4种三卤甲烷类消毒副产物(THMs,三氯甲烷、二氯一溴甲烷、一氯二溴甲烷和三溴甲烷)和两种卤乙酸类消毒副产物(HAAs,二氯乙酸和三氯乙酸),采用美国环保局推荐的低剂量致癌风险评价方法对其进行评价。结果所有消毒副产物检出值都低于《生活饮用水卫生标准》(GB 5749-2006)[1]的限值。THMs在丰水期的含量高于枯水期的含量,有明显的季节特征。而HAAs则无明显变化规律。无锡地区6种DBPs对成人的致癌风险均超过了USEPA认为可以忽略的水平(<10-6),处于具有潜在致癌风险的区间(10-6~10-4),其中各DBPs总致癌风险从高到低分别为三氯乙酸>二氯乙酸>一氯二溴甲烷>三溴甲烷>二氯一溴甲烷>三氯甲烷。结论无锡地区出厂水中THMs有明显的季节性特征,DBPs对成人具有潜在的致癌风险。     

饮用水重金属等污染物健康风险的初步评价

重金属作为环境中普遍存在的一类高稳定、难降解、可累积的污染物,可通过工农业及生活废水的排放等途径进入水体,对水体环境和水生动植物产生严重危害,并可通过饮水、食物链等途径直接或间接的影响到人类的健康。针对目前重金属污染危害人体健康集中爆发的情况,以黄河下游地区A省及其省会B市为例,对全省饮用水中的镉、铬(六价)、铅、汞等重金属元素和砷等元素浓度进行了调查研究,应用美国环保局推荐的健康风险评价模型对饮用水中金属元素及砷所引起的健康风险度作了初步评价。结果表明,A省和B市饮用水中的砷和镉、铬(六价)、铅、汞重金属平均浓度分别为2.3μg/L、1μg/L、4.2μg/L、5μg/L、0.044μg/L和0.94μg/L、0.9μg/L、4.3μg/L、4.3μg/L、0.044μg/L;通过饮水途径引起的致癌健康风险中A省、B市的铬(六价)致癌风险均为最大,风险分别为8.252×10-5·a-1和8.32×10-5·a-1,略高于国际辐射防护委员会(ICRP)推荐通过饮水途径最大可接受风险水平(5×10-5·a-1),因此B市乃至A省的供水水质仍存在一定的健康风险,需要对饮用水中砷及重金属含量及时检测,并优先对其进行管理和控制。     

Population health risk due to dietary intake of heavy metals in the industrial area of Huludao City, China

For most people, diet is the main route of exposure to trace metals, so the assessment risks of these elements to human via dietary intake is important. The non-carcinogenic health risk of Hg, Pb, Cd, Zn and Cu to the adults and children via dietary intake in the industrial area of Huludao city, northeast of China was estimated. The industrial area of Huludao has been contaminated seriously by heavy metals due to heavy metals smelting. The target hazard quotients (THQs) and hazard index (HI) were calculated to evaluate the non-carcinogenic health risk from individual heavy metal and combined heavy metals due to dietary intake. Target hazard quotients for individual heavy metal from consuming individual foodstuff in the industrial area of Huludao were all less than one, indicating that health risk associated with the intake of a single heavy metal through consumption of only one kind of foodstuffs (e.g. vegetable) was the relative absent. However, consumption of the entire foodstuff would lead to potential health risks for children and adults, since hazard indexes (HIs) for heavy metals due dietary intake were higher than one. The relative contributions of Hg, Pb, Cd, Zn and Cu to the HIs were 1.7%, 11.7%, 24.0%, 23.4%, and 39.6% for adults, and 1.5%, 11.7%, 21.8%, 26.1%, and 38.8% for children. Cereal, sea product, and vegetable were the main sources of heavy metal intake from foodstuff for adults and children, but fruit, milk, bean, and egg were secondary contributors.     

Ambient trace element background concentrations in soils and their use in risk assessment

The definition of ambient background concentrations (ABCs) is used in this study to assess the potential environmental risk of trace elements in soils and parent materials from Granada, Spain. Two different layers of soil (0-20 and 20-40 cm) and parent material samples were collected at 93 sites. From cumulative frequency distribution curves, ABCs for As, Co, Cu, Cr, Ni, Pb and Zn were estimated at 3.5-20, 7-23, 13-25.6, 29-66, 7-20, 15-36, and 5.5-76 mg kg^− 1, respectively. Tukey box-plots were used to discriminate different concentration classes and identify potentially contaminated sites. Weakly-weathered soils (Entisols) over carbonate materials showed the lowest background contents, the most developed soils (Alfisols) over metamorphic rocks the highest ones. Outliers were mainly found near a former iron mine where arsenic concentrations were by far exceeding the corresponding regional ABC. These soils were however, not toxic to Escherichia coli and Vibrio fischeri. The prediction of site-specific ABCs together with bioavailability and toxicity assessment is a valuable tool for giving further insight into the risk of trace elements in soils.     

酸雨作用下含磷固化剂处理铅锌镉复合污染土的半动态浸出试验研究

酸雨pH可显著影响固化重金属污染土的浸出量。定量评价固化污染土在暴露条件下(例如酸雨)对周边水土体环境的影响,需要明确固化污染土的有效扩散系数和阻滞因子这两个关键参数。现有研究多集中在固化污染土的浸出特性和表观扩散系数,有关有效扩散系数和阻滞因子的研究很少。本次研究旨在研究改进的KMP固化剂固化重金属Pb、Zn、Cd复合污染土在酸雨作用下的有效扩散系数和阻滞因子。解吸附试验表明,随着污染土中重金属Pb、Zn、Cd浓度增加,固化污染土的解吸附量增大,且解吸附曲线满足Freundlich平衡吸附/解吸附方程。半动态浸出试验结果表明,污染土中重金属Pb、Zn、Cd浸出机制主要由扩散控制,且拟合曲线斜率分别为0.60,0.56和0.61,表观扩散系数Dobs为1.05×10~(-16),7.84×10~(-13)和2.11×10~(-12) m~2/s。结合解吸附试验和半动态浸出试验结果可知,Pb、Zn、Cd的阻滞因子Rd分别为17165.6,254.6和109.3,有效扩散系数De分别为1.82×10~(-12),1.96×10~(-10),2.34×10~(-10) m~2/s。与其他学者结果相比,固化污染土中Pb的有效扩散系数低于其他学者的两个数量级,而Zn和Cd的求算结果与其他学者一致。     

Organochlorine pesticides (OCPs) in air-conditioner filter dust of indoor urban setting: Implication for health risk in a developing country

This preliminary investigation highlights the occurrence of organochlorine pesticides (OCPs) in the indoor environment of a megacity, Lahore, Pakistan using the dust ensnared by air-conditioner filters. The Σ₁₆OCPs concentration ranged from 7.53 to 1272.87 ng/g with the highest percent contribution by ΣDDT (dichlorodiphenyltrichloroethane; 87.21%) and aldrin (6.58%). The spatial variation of OCPs profile revealed relatively higher concentration from homes near to agricultural and abandoned DDT manufacturing sites. Calculated isomer ratios revealed historic sources of hexachlorocyclohexanes (HCHs) and the fresh input of technical DDT and chlordane by the dwellers. The air conditioner dust was helpful to better understand the health risk in the indoor environment. So far a high lifetime cancer risk (10⁻³) was predicted for toddlers via accidental ingestion, inhalation, and dermal exposure. Similarly, the non-carcinogenic risk-based hazard quotient was found to be high for toddlers (6.94) and within the permissible limit (<1) for adults.     

Trace element reference values in tissues from inhabitants of the European Community. III. The control of preanalytical factors in the biomonitoring of trace elements in biological fluids.

In the context of a programme concerning the determination of trace elements in body fluids and tissues to establish trace element reference values, research has been undertaken on the control of preanalytical factors in order to develop sufficiently accurate and precise guidelines to be applied in routine work by using techniques such as graphite furnace atomic absorption spectroscopy (GFAAS). Aspects investigated are related to the risk of contamination during blood collection and the use of anticoagulants; the risk of losses during storage and freeze-drying as well as the possible risk of contamination arising from trace elements in airborne particulates of the laboratory environment. For the analysis of Al, Ba, Cd, Co, Cr, Mn, Mo, Ni, Sb, W, V and Zn in blood, Teflon cannula is the method of choice. The anticoagulants do not introduce disturbing contaminations of Rb, Se, Zn, while contaminations were observed for Co, Cr, Mn. Radiotracers in 'metabolized form' (radiolabelled rat or rabbit tissues from animals administered with radioisotopes) show that samples stored for 1 month at -20 degrees C have no significant trace metal losses. Strict ambient air quality standard has to be respected (continuous monitoring) due to the possibility of element contaminations inside the laboratory. The use of matrix modifiers could represent a toxicological risk to the operators. Critical factors should be considered ('metal sheets') for each element in each matrix. For instance 27 factors for Cr in serum have been suggested.     

Health risk assessment of inorganic arsenic intake of Cambodia residents through groundwater drinking pathway

In order to compare the magnitudes and health impacts of arsenic and other toxic trace elements in well water, groundwater and hair samples were collected from three areas with different arsenic exposure scenarios in the Mekong River basin of Cambodia. Ampil commune in Kampong Cham province was selected as an uncontaminated area, Khsarch Andaet commune in Kratie province was selected as a moderately contaminated area, and Kampong Kong commune in Kandal Province was selected as an extremely contaminated area. Results of ICP-MS analyses of the groundwater samples revealed that As, Mn, Fe and Ba concentrations were significantly different among the three study areas (Kruskal-Wallis test, p < 0.0001). Out of 46 observed wells in the Kandal province study area, 100% detected As > 50 μg L⁻¹ and Fe > 300 μg L⁻¹; 52.17% had Mn > 400 μg L⁻¹ and 73.91% found Ba > 700 μg L⁻¹. In the Kratie province study area (n = 12), 25% of wells showed elevated arsenic levels above 10 μg L⁻¹ and 25% had Mn > 400 μg L⁻¹, whereas samples from Kampong Cham province study area (n = 18) were relatively clean, with As < 10 μg L⁻¹. A health risk assessment model derived from the USEPA was applied to calculate individual risks resulting from drinking groundwater. Computational results indicated that residents from Kandal Province study area (n = 297) confronted significantly higher non-carcinogenic and carcinogenic risks than those in Kratie (n = 89) and Kampong Cham (n = 184) province study areas (Kruskal-Wallis test, p < 0.0001). 98.65% of respondents from the Kandal province study area were at risk for the potential non-cancer effect and an average cancer risk index was found to be 5 in 1000 exposure. The calculations also indicated that, in the Kratie province study area, 13.48% of respondents were affected by non-cancer health risks and 33.71% were threatened by cancer, whereas none of respondents in the Kampong Cham province study area appeared to have non-carcinogenic effect. Positively significant correlations of the arsenic content in scalp hair (As_h) with both arsenic levels in groundwater (As_w) (r_s (304) = 0.757, p < 0.0001) and individual average daily doses (ADD) of arsenic (r_s (304) = 0.763, p < 0.0001) undoubtedly indicated that arsenic accumulation in the bodies of Cambodia residents in the Mekong River basin was mainly through a groundwater drinking pathway. To the best of our knowledge, this is the first comprehensive report comparing individual health risk assessments of arsenic exposure through a groundwater drinking pathway to enriched arsenic levels from groundwater in the Mekong River basin, Cambodia. This study indicates that elevated arsenic concentrations in groundwater may lead to thousands of cases of arsenicosis in the near future if mitigating actions are not taken.     

Risk assessment of exposure to volatile organic compounds in groundwater in Taiwan

The purpose of this study is to assess the risks from exposure to 14 volatile organic compounds (VOCs) in selected groundwater sites in Taiwan. The study employs the multimedia environment pollutant assessment system (MEPAS) model to calculate the specific non-cancer and cancer risks at an exposure level of 1 μg/L of each VOC for a variety of exposure pathways. The results show that the highest specific non-cancer risk is associated with water ingestion of vinyl chloride (VC) and that the highest specific cancer risk is associated with indoor breathing of VC. The three most important exposure pathways for risk assessment for both non-cancer and cancer risks are identified as water ingestion, dermal absorption when showering, and indoor breathing. Excess tetrachloroethylene (PCE), trichloroethylene (TCE), dichloroethylene (DCE), and VC are detected in the groundwater aquifers of one dump site and one factory. However, the study suggests that the pollutants in the contaminated groundwater aquifers do not travel extensively with groundwater flow and that the resulting VOC concentrations are below detectable levels for most of the sampled drinking-water treatment plants. Nevertheless, the non-cancer and cancer risks resulting from use of the contaminated groundwater are found to be hundred times higher than the general risk guidance values. To ensure safe groundwater utilisation, remediation initiatives for soil and groundwater are required. Finally, the study suggests that the current criteria for VOCs in drinking water might not be capable of ensuring public safety when groundwater is used as the primary water supply; more stringent quality criteria for drinking water are proposed for selected VOCs.     

非饱和导排结构控制降雨入渗的边坡物理模型试验

膨胀土渠坡失稳是影响南水北调中线供水工程安全性的重要因素之一,而对其边坡进行防渗处理是解决膨胀土边坡失稳的有效途径。针对传统边坡防渗处理方法(面板与土工布覆盖等)存在生态功能弱以及使用寿命短等不足,开展了非饱和导排结构的边坡防渗效果的物理模型试验研究。利用土壤剖面负压动态监测数据,采用非饱和渗流理论,在不同降雨强度与不同初始含水量条件下,对比分析了两种非饱和导排结构即细/粗粒二元结构和粗粒单一结构,控制降雨入渗边坡的效果。研究结果表明:在降雨强度为4.18×10-4 cm/s的情况下,二元结构能有效阻止降雨入渗;且细粒层初始含水量越低,其储水能力越强,二元结构控制降雨入渗的效果相对越好。在降雨强度为1.72×10-4,4.18×10-4,4.97×10-4 cm/s的情况下,粗粒层单一结构对降雨入渗边坡均具有一定的控制作用,但有5.6%~10.7%的降雨从模型底部排出,存在入渗风险。总体上,从排水–渗流控制效果与生态功能角度考虑,二元结构明显优于单一结构。研究成果可为解决南水北调膨胀土边坡以及其它工程边坡的渗流控制问题提供技术支撑。     

Calcium polysulfide remediation of hexavalent chromium contamination from chromite ore processing residue

Past disposal of high-lime chromite ore processing residue (COPR) from a chemical works in S.E. Glasgow, UK, has led to continuing release of toxic and carcinogenic hexavalent chromium (Cr(VI)) to groundwaters which are highly contaminated with Cr(VI)O4(2-). Traditional methods of remediating Cr(VI)-contaminated land, e.g. using ferrous sulfate and organic matter, have had limited success in converting Cr(VI) to less harmful and insoluble Cr(III). This paper describes the first application of calcium polysulfide (CaS(x)) to the remediation of contaminated groundwater and high-lime COPR in a series of laboratory experiments, which have demonstrated the effectiveness of the treatment in quantitatively and rapidly reducing Cr(VI) to Cr(III) over the pH range (8-12.5) typically found at the sites. Cr(III)-organic complexes, present in groundwater at one location, were also effectively precipitated upon treatment with CaS(x). The potential for large-scale use of CaS(x) in the remediation of Cr(VI) from COPR is also discussed.     

FCKW als Tracer für die Ausbreitung von Altablagerungsemissionen im Grundwasser

Emissions from abandoned waste disposal sites into groundwater are difficult to trace further downstream because of their complexity. Typical tracers, for example, like chloride, boron and sulphate are likely to be influenced by several factors like saline waters, emissions from seepage pits and leaky sewers. These types of components are therefore not suitable to characterise groundwater contamination caused by abandoned waste disposal sites; they will thus not be further discussed in this paper. However, due to their special geochemical properties like negligible absorption and degradation rates, chlorinated fluorocarbons, especially difluoro-dichloromethane (F12), which are frequently emitted from abandoned waste disposal sites, are particularly suitable for the detection of maximum contaminant emissions to groundwater. These elements are crucial for the assessment of groundwater contamination and the employment of natural attenuation as a remediation measure.