[Hydraulic fracturing - a hazard for drinking water?]. / Fracking - eine Gefahr für das Trinkwasser?

Hydraulic fracturing (fracking) is a technique used to release and promote the extraction of natural gas (including shale gas, tight gas, and coal bed methane) from deep natural gas deposits. Among the German public there is great concern with regard to the potential environmental impacts of fracking including the contamination of ground water, the most important source of drinking water in Germany. In the present article the risks of ground water contamination through fracking are discussed. Due to the present safety requirements and the obligatory geological and hydrogeological scrutiny of the underground, which has to be performed prior to fracking, the risk of ground water contamination by fracking can be regarded as very low. The toxicity of chemical additives of fracking fluids is discussed. It is recommended that in the future environmental impact assessment and approval of fracs should be performed by the mining authorities in close cooperation with the water authorities. Furthermore, it is recommended that hydraulic fracturing in the future should be accompanied by obligatory ground water monitoring.

The German Human Biomonitoring Commission.

In Germany, the Human Biomonitoring Commission of the German Federal Environment Agency was established in 1992 to develop scientifically based criteria for the application of human biomonitoring (HBM). The goal is to clarify fundamental and practical issues related to HBM. Following the assessment of pollutants in body fluids, the commission derives two different kinds of guideline values: reference values and HBM values (HBM I and HBM II values). This article gives a review of the current reference values, HBM values, and the work of the German Human Biomonitoring Commission.

[10-year PCB Guideline--attempt to balance hygienic and medical/environmental-toxicological views]. / Zehn Jahre PCB-Richtlinie -- Versuch einer Bilanz aus hygienischer und umweltmedizinisch-toxikologischer Sicht.

PURPOSE: In 1995 a guideline was established in Germany, which requires the remediation of buildings with elevated indoor air concentrations of polychlorinated biphenyls (PCB). The action limit is 3000 ng/m(3). The tolerable PCB indoor air concentration is 300 ng/m(3). The aim of remediation actions is to reduce PCB in indoor air to levels < 300 ng/m(3) by removing the sources of PCB in buildings (mainly sealants, ceiling plates, wall colours). Based on this guideline a great number of school buildings, university buildings and administration buildings constructed in the 1960-ties and 1970-ties were renovated. In this paper, the toxicological basis of the aforementioned guide values are discussed. Furthermore, recent papers and proposals to establish lower guideline values for PCB in indoor air are discussed. CONCLUSIONS: The existing PCB guideline should be revised. When revising the guide values for PCB in indoor air it should be kept in mind that human PCB exposure is mainly via food, that PCB intake via food has been declining since more than 20 years, and that there is only a minor increase of PCB blood levels following inhalation of PCB in indoor air. In public discussions it should be clearly stated that remediation of PCB contaminated buildings is a preventive action. PCB concentrations in indoor air, which are associated with significant health risks, are presumably much higher than the current action value.

[Risk assessment of soil contamination in a residential area: the importance and role of human biological monitoring--a case report]. / Gefährdungsabschätzung von Bodenverunreinigungen in einem belasteten Wohngebiet: Bedeutung und Funktion des Human-Biomonitoring -- ein Fallbeispiel.

BACKGROUND AND PURPOSE: High levels of arsenic, cadmium, mercury and polychlorinated dibenzodioxins and dibenzofuranes (PCDD/PCDF) were detected in the soil of a residential area located at the river Elbe near Hamburg (Germany). Soil contamination resulted from sediments from the Hamburg harbour and from the Elbe that were deposited in this area up to the late 1950ies. The objective of this study was to evaluate whether the soil contamination in this area is associated with increased levels of arsenic, heavy metals and PCCD/PCDF in the blood and urine of selected residents living on highly contaminated grounds. RESULTS: The blood levels of lead and PCDD/PCDF and the urine levels of arsenic, cadmium and mercury that were measured in 29 residents living on highly contaminated grounds were not elevated in relation to a control group. All individual values were in the range of the background exposure levels of the general population. There were no signs of an increased additional exposure related to soil contamination. CONCLUSIONS: Based on the results of this study it was agreed to refrain from an expensive redevelopment of this area. As a preventive measure some recommendations were given to the residents to minimize possible exposure to soil contaminants. Human biological monitoring studies should be an essential part of exposure and risk assessment of soil contaminations in residential areas in future studies and as a basis for adequate risk management.

Decrease of PCDD/F levels in human blood--trend analysis for the German population, 1991-1996.

More than 500 whole blood samples of normal subjects from Germany collected in 1991-1996 have been analyzed for polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) by capillary gas chromatography/high-resolution mass spectrometry. Over the examined time period a continuous decrease of the PCDD/F concentrations in human blood was observed. The mean levels found were about 42.7 pg I-TEq/g (lipid basis) in 1991 and 20.7 pg I-TEq/g (liquid basis) in 1996 [median: 40.8 and 19.2]. A reduction to about half was found for most congeners. Each 1-year subset of the entire collective shows a positive correlation of the PCDD/F blood levels with age for most of the congeners, the sum values, and the calculated toxicity equivalents. For statistical evaluation a multiplicative model was used: Concentration in blood = A x ageB. The correlation is mostly pronounced for lower chlorinated PCDD and for 2,3,4,7,8-PentaCDF.

Decrease of PCDD/F levels in human blood from Germany over the past ten years (1989-1998).

744 whole blood samples of normal subjects from Germany collected in 1989-1998 have been analyzed for polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) by capillary gas chromatography/high resolution mass spectrometry. Over the examined time period a continuous decrease of the PCDD/F concentrations in human blood was observed. The mean levels found were 43.7 pg I-TEq/g (lipid basis) in 1989 and 20.7 pg I-TEq/g (lipid basis) in 1996/98 [median: 42.2 and 19.4]. The reduction to about the half was found for most congeners. Each one-year subset of the collective and the entire collective shows a positive correlation of the PCDD/F blood levels with age for most of the congeners, the sum values and the calculated toxicity equivalents. For statistical evaluation a multiplicative model was used: Concentration = A x Age(B). The correlation is mostly pronounced for lower chlorinated PCDD and for 2,3,4,7,8-PentaCDF. The PCDD/F concentrations in human blood in relation to the year of examination and the age of the subjects can be described by a linear model: I-TEq [pg/g (lipid basis)] = 6176 - 3.097 x Year + 0.6482 x Age or by a multiplicative model: I-TEq [pg/g(lipid basis)] = 10(89.08-0.04415 x Year + 0.008468 x Age).

Reference values and human biological monitoring values for environmental toxins. Report on the work and recommendations of the Commission on Human Biological Monitoring of the German Federal Environmental Agency.

This article describes the working principles and working procedures of the Commission on Human Biological Monitoring, which was established in 1993 as a joint commission of the Federal Health Office (Bundesgesundheitsamt) and the Federal Environmental Agency (Umweltbundesamt) in Germany. One of the main tasks of the commission is to develop scientifically based criteria for the application of human biological monitoring and for the evaluation of human monitoring data in environmental medicine. In principle, two different kinds of criteria are recommended: (a) reference values and (b) human biological monitoring values (HBM values). Reference values are intended to indicate the upper margin of the current background exposure of the general population to a given environmental toxin at a given time. Reference values can be used to identify subjects with an increased level of exposure (in relation to background exposure) to a given environmental toxin. However, reference values do not represent health-related criteria for the evaluation of human biological monitoring data. HBM values are derived from human toxicology and epidemiology studies and are intended to be used as a basis for a health-related evaluation of human biological monitoring data. Usually the commission recommends two different HBM values: HBM I, the concentration of an environmental toxin in a human biological material (usually blood, serum, plasma, or urine) below which there is--according to the knowledge and judgement of the commission--no risk for adverse health effects in individuals of the general population: and HBM II, the concentration of an environmental toxin in a human biological material (usually blood, serum, plasma, or urine) above which there is--according to the knowledge and judgement of the commission and with regard to the environmental toxin under consideration--an increased risk for adverse health effects in susceptible individuals of the general population. The HBM I value can be considered a kind of alert value (from the toxicological point of view), whereas the HBM II value represents a kind of action level, at which attempts should be undertaken to reduce the level of exposure immediately and to carry out further medical examinations. Values between HBM I and HBM II should be considered a warning signal of the need to control the analytical measurement and to reduce the level of exposure of the concerned individual as reasonably as is achievable. At present, reference and HBM values are available for lead in blood, for cadmium and mercury in blood and urine, and for pentachlorophenol in plasma/serum and urine. Reference values have been established for some polychlorinated biphenyls in blood and plasma as well as for hexachlorocyclohexane and hexacholorobenzene in blood as well as for some organochlorine in human milk.

Sick building syndrome in an office building formerly used by a pharmaceutical company: a case study.

In the past two decades, a group of health problems related to the indoor environment--generally termed sick building syndrome (SBS)--has emerged. We present an investigation of SBS in employees of a ministry working in a naturally ventilated office building that formerly had been used by a pharmaceutical company. A preceding environmental monitoring had failed to identify the cause(s) for the complaints. We conducted a questionnaire-based investigation and categorized the building sections and rooms according to their renovation status and their former use, respectively. The highest level of complaints was found among the employees working in rooms that in the past had been used for the production or storage of various pharmaceutical products suggesting that pharmaceutical odors may be a risk factor for SBS. Clinical laboratory tests did not show any unusual results. We conclude that the former use of a building for production and storage of pharmaceutical products should be considered as a possible risk factor for complaints about indoor air quality, e.g., when advising about or planning for renovations of buildings formerly used for production, handling, or storing of chemicals.

[Statistically evaluated 95% prediction ranges as alternative to reference ranges exemplified by polychlorinated dibenzo-p-dioxins/dibenzofurans and lead]. / Aus anlassbezogenen Untersuchungen statistisch berechnete 95%-Prognosebänder als Alternative zu Referenzbereichen am Beispiel von polychlorierten Dibenzo-p-dioxinen/Dibenzofuranen und Blei.

Using the 95% prediction limits of an age-related multiplicative regression model describing the datasets of blood examinations carried out on subjects suspected of having been exposed to lead and to polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/F), it was shown that the relevant curves can be used as an alternative to reference ranges describing the actual background exposure to these pollutants. The upper limit of the actual German background exposure can be estimated by the following equations: PCDD/F as International Toxicity Equivalents in the age range of 10-70 years [pg/g lipid basis] = 1.64.age0.871 and lead in the age range of 15-80 years [microgram/l] = 18.15.age0.3638.

[Blood tests for PCB in teachers at a heavily PCB-polluted school]. / Blutuntersuchungen auf PCB bei Lehrerinnen und Lehrern einer stark PCB-belasteten Schule.

The levels of PCB 28, 52, 101, 153, 138 and 180 were determined in blood samples of subjects (mainly teachers; n = 18) who had worked in a PCB-contaminated school-building for many years (average: 14.2 years). The PCB concentrations in indoor air ranged up to 13,500 ng/m3. For comparison PCB blood levels were determined in 18 teachers working in schools not contaminated by PCB. The subjects of the reference group were matched with the exposed subjects with respect to age and gender. PCB 28, 52 and 101 were not detectable in the blood samples (detection limit: 0.1 microgram/l). In the exposed subjects blood levels of PCB 153 and 138 were, on average, slightly higher and the levels of PCB 180 slightly lower when compared with the reference subjects, but the differences were not statistically significant. The levels of PCB 153, 138 and 180 increased with age. With the exception of two subjects the levels of these congeners were below the reference values proposed by Kappos et al. The results show that inhalative exposure to PCB 153, 138 and 180 is very low in comparison to PCB background exposure via food. Due to rapid metabolisation and elimination the blood levels of PCB 28, 52 and 101 are usually very low.

[PCDD/F-content in house dust]. / PCDD/F-Gehalte im Hausstaub.

The levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) were determined in house dust samples collected from 22 residential houses located in different areas of Germany. Nine houses were located in an urban and industrial area, one house in a rural and 10 houses in a contaminated residential area near to a former metal reclamation plant. Two house dust samples were collected from two old farm houses, in which large amounts of pentachlorophenol (PCP) containing wood preservatives had been used several years ago. All dust samples were collected from the dust bags of vacuum cleaners and passed through a sieve (mesh: 2.0 mm). Particles < 2.0 mm were used for analysis. The average level of PCDD/F in "normal" house dust was 101 ng I-TEq/kg (range: 7.83-332 ng I-TEq/kg). The predominant congeners and chlorohomologues were OctaCDD followed by HeptaCDD, HeptaCDF and OctaCDF. The average level of PCDD/F in house dust samples collected from a contaminated residential area was 265 ng I-TEq/kg (range: 29.9-1050 ng I-TEq/kg). When compared with "normal" residential houses significantly increased levels of lower chlorinated PCDD/F were noted in the house dust samples from this area. The house dust samples collected from a PCP-treated old farm house were found to contain 1.39 and 11.8 micrograms I-TEq/kg. The chlorohomologues patterns were typical for PCP contaminated with PCDD/F. The present study shows that the levels of PCDD/F in house dust may be used as indicators of indoor contamination by PCDD/F and as reference values for further investigations.

[Human biomonitoring--studies of arsenic, lead and PCDD/F in inhabitants of a contaminated residential area]. / Human-Biomonitoring--Untersuchungen auf Arsen, Blei und PCDD/F bei Bewohnern eines kontaminierten Wohngebietes.

The levels of arsenic in urine, lead in blood, and PCDD/F in blood fat were determined in 12 subjects living in a residential area where the soil was contaminated by arsenic, lead, PCDD/F and other pollutants. Six residents (group I, mean age 56 years) were living on the contaminated site for at least 35 years, and had consumed home-grown vegetables and fruits as well as self-produced animal products (eggs, meat). Six residents (group II, mean age 47 years) had been living on the contaminated site for an average period of 9 years, and had consumed only minor amounts of home-grown vegetables and fruits, but no self-produced animal products. Some of them had skin contact with contaminated soil during excavation and garden work. For comparison, blood and urine samples of subjects living in the same region but not exposed to soil contaminants were investigated for the above mentioned parameters. The reference subjects were selected by age and gender in order to form matched pairs with the exposed subjects. The levels of arsenic in urine and lead in blood did not differ significantly between the residents of the contaminated area and the reference subjects. With regard to PCDD/F in blood fat a significantly increased PCDD/F-body burden was found for the subjects of group I (median: 41.5 pg I-TE/g fat, range: 18.0-54.6 pg I-TE/g fat; reference group, median: 20.3 pg I-TE/g fat, range: 12.2-30.5 pg I-TE/g fat), whereas the subjects of group II had only a moderately, but not significantly increased PCDD/F-body burden (median: 23.4 pg I-TE/g fat, range 13.1-45.8 pg I-TE/g fat) when compared with the reference group (median: 13.9 pg I-TE/g fat, range: 12.1-30.5 pg I-TE/g fat). Increased PCDD/F levels in blood fat seemed to be related mainly to the consumption of self-produced animal products. From the present-day toxicological point of view, none of the subjects examined in this study had a critical body burden of PCDD/F.

Urinary levels of 1-hydroxypyrene, 1-, 2-, 3-, and 4-hydroxyphenanthrene in females living in an industrial area of Germany.

The concentrations of 1-hydroxypyrene (1-HOPYR), and 1-, 2-, 3-, and 4-hydroxyphenanthrene (HOPHE) as metabolites of pyrene and phenanthrene, were measured in urine samples collected from 124 housewives (27 smokers and 97 non-smokers) living in Bottrop, an industrial city located in the Ruhr area in Germany. The urine samples were analyzed by a very sensitive and practical high-performance liquid chromatographic (HPLC) method using a two-column switching technique and a special precolumn packing material followed by fluorescence detection. The polycyclic aromatic hydrocarbon (PAH) metabolites are selectively enrichéd on the precolumn and separated from the matrix. Therefore, laborious clean-up steps were omitted. The above-mentioned PAH metabolites could be detected in all urine samples investigated. Smokers had significantly higher urine concentrations of 1-HOPYR (median 0.48 microgram/g creatinine), 3-HOPHE (median 0.61 microgram/g creatinine), 2-HOPHE (0.41 microgram/g creatinine) and 4-HOPHE (median 0.10 microgram/g creatinine) than non-smokers (median 0.15 microgram/g creatinine, 0.31 microgram/g creatinine, 0.31 microgram/g creatinine and 0.04 microgram/g creatinine, respectively). The study shows that the influence of smoking is of such an order of magnitude that potential environmental exposure to PAH in this highly industrialized area is obscured by smoking habits. Furthermore, it can be concluded that the determination of 1-HOPYR, 1-, 2-, 3-, and 4-HOPHE in urine is a diagnostically useful method for the biological monitoring of persons environmentally exposed to PAH.

Levels of PCDD/PCDF in blood fat as indices of the PCDD/PCDF body burden in humans.

The levels of PCDD/F in blood fat are similar to those in body fat and in milk fat of lactating women. Therefore, the levels of PCDD/F in blood fat can be used as an index of the individual PCDD/F body burden in humans. In order to evaluate the PCDD/F background exposure levels of the German population, blood samples collected from 95 subjects (age 12-82 years) living in a rural area of North-West Germany were analysed for PCDD/F. The median 2,3,7,8-TCDD toxicity equivalents (TE) were 40.8 pg I-TE/g blood fat and the 95th percentile was 82.1 pg I-TE/g blood fat. The TE levels in blood fat show a marked increase with age, which reflects the pronounced accumulation of PCDD/F in the human body throughout the entire lifetime. Considering single congeners, significant differences in the age-related increase were noted. Using age-specific reference values derived from this study the levels of PCDD/F in blood fat of individuals environmentally exposed to PCDD/F under different circumstances were evaluated.

[Blood PCDD/F levels in blood of residents of a former cable incineration facility]. / PCDD/F-Gehalte im Blut von Anwohnern einer früheren Kabelabbrennanlage.

Increased levels of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofuranes (PCDF) were found in soil and roof dust of a residential area located near a metal reclamation plant in Northern Germany. In order to assess the degree of exposure of persons residing near to this plant, venous blood samples were collected from 14 subjects and analysed for PCDD/F and fat content. Furthermore, blood samples collected from the members of a farmer's family living nearby were analysed for PCDD/F. Previous studies had shown significantly increased PCDD/F levels in chicken eggs produced on this farm. Regarding the group of residents, the PCCD/F levels in blood fat were not increased when compared to background levels. However, some members of the farmer's family had increased PCDD/F levels in blood fat. The findings of these studies suggest that long-term consumption of contaminated animal products, especially chicken eggs, may result in increased PCDD/F levels in the body, whereas increased levels of PCDD/F in dust and soil do not noticeably affect the PCDD/F levels in human blood fat.

[Lead and cadmium content in deciduous teeth of children of Stolberg and other cities of North-Rhine-Westphalia: a chronological trend 1968-1993]. / Blei- und Cadmiumgehalte in Milchschneidezähnen von Kindern aus Stolberg und anderen Städten Nordrhein-Westfalens: Entwicklungstrend 1968-1993.

The levels of lead and cadmium were determined in deciduous teeth (incisors only) of children living in Stolberg and some other cities located in North-Rhine-Westfalia, Germany. The Stolberg children were born in 1968-1973 (group 1; n = 103) and 1982/1983 (group 2; n = 103). The other children (n = 109) were born between 1979 and 1986. All teeth were analysed within the same analytical series by atomic absorption spectrometry (AAS). The results show that the average levels of lead and cadmium in milk teeth have decreased significantly in the time period from 1970 to 1990. Considering the Stolberg children the fall of tooth lead was about 50% and the fall of tooth cadmium was about 60%. Children from other cities show a comparable decrease of tooth lead and tooth cadmium. The results indicate that a significant decrease of the lead body burden and cadmium body burden of children and probably also of the general population of Germany has occurred during the last years.

Lead exposure of the child population in Greece.

Lead exposure of the child population was studied in three different areas in Greece: Kalamata which is a rural area of Southern Greece; Tavros, a district of Athens with a considerable industrial activity; and Lavrion, a small city near Athens where a lead-zinc mining and smelting industrial complex has existed for more than 90 years. The results were evaluated with respect to a number of individual, social and environmental variables (i.e. smelter, occupation of the father) especially those concerning the area of Lavrion which is the most heavily polluted area in Greece. The results of this study can be considered as an index for the extent of the lead pollution problem in the named areas of Greece.

[Dioxin level of small volume gardeners in Duisburg]. / Untersuchungen zur Dioxinbelastung von Kleingärtnern aus Duisburg.

The PCDD/F levels were determined in the venous blood of 21 allotment gardeners in Duisburg (Germany). Soil analyses had shown elevated levels of PCDD/F in garden soil (range 16.4-77.6 ng I-TE/kg). Vegetable plants also had elevated levels of PCDD/F, mainly due to airborne contamination. The highest levels were found in kale (2.6-65.6 ng I-TE/kg d.w.) and endive (1.7-28.5 ng I-TE/kg d. w.). The study population consisted of 5 females and 16 males (mean age 57 years; range 43-67 years), who had been cultivating their allotment gardens for an average of 20 years (range 7-36 years). About 50% of their total vegetable consumption and 30% of their fruit consumption were from their own gardens. The mean 2.3.7.8-TCDD toxicity equivalents (TE) of PCDD/F in blood fat were 44.3 pg I-TE/g fat (range 29.2-81.1 pg I-TE/g fat). Compared to reference data these values are within the range of background PCDD/F-levels in the German population. The concentrations in individual gardeners as well as the congener pattern were not different from those of normal subjects. The present study shows that increased levels of PCDD/F in garden soil and garden products do not have a significant effect on the PCDD/F burden in gardeners, even if they consume homegrown vegetables and fruits from their own allotment gardens for many years in succession.

[Digoxin content in blood lipids of children, athletes, sports ground attendants and residents after content with dioxin-containing surface slag (Kieselrot)]. / Dioxingehalte im Blutfett von Kindern, Sportlern, Platzwarten und Anwohnern nach Kontakt mit dioxinhaltigen Tennenflächen (Kieselrot).

In 1991 it was discovered, that a large number of sporting grounds and playgrounds in Germany were covered with a waste slag material from a former copper smelter located at Marsberg, Germany. This material was found to contain high levels of PCDD/F ranging up to 100,000 TE/kg. The objective of the present study was to assess whether subjects sporting on such grounds had elevated levels of PCDD/F in blood. PCDD/F in blood fat was used as an indicator of the PCDD/F body burden. Additionally, six children and seven residents of a contaminated sporting and playground were examined. Generally, the levels of PCDD/F in blood fat were in the range of background levels in all subjects. Taking into account the effect of age, slightly elevated blood levels of PCDD/F were detected in children. The results show that the bioavailability of PCDD/F in the slag material is very low. However, from the preventive point of view children who might ingest slag material by hand-to-mouth-activities, should not play on such contaminated playgrounds.