Human biomonitoring (HBM)-II values for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) - Description, derivation and discussion.

For evaluation of internal exposure to harmful substances, the Human Biomonitoring Commission of the German Environment Agency (HBM Commission) develops toxicologically justified assessment values (HBM-I and HBM-II). The HBM-I value corresponds to the concentration of a compound in human biological material below which no adverse health effects are expected to occur. Consequently, no action is required when the HBM-I value is not exceeded (HBM-Commission, 1996). In 2016, the HBM Commission developed HBM-I values of 2 ng PFOA/mL and 5 ng PFOS/mL in blood serum or plasma, respectively. A detailed delineation of supporting arguments was published in April 2018 (HBM-Commission, 2018). In contrast to the HBM-I, the HBM-II value corresponds to the concentration in human biological material which, when exceeded, may lead to health impairment which is considered as relevant to exposed individuals (HBM-Commission, 1996, HBM-Commission, 2014). HBM-II VALUES FOR PFOA AND PFOS: On September 17, 2019, the HBM Commission of the German Environment Agency established the following HBM-II values: Women at child-bearing age: 5 ng PFOA/mL blood plasma; 10 ng PFOS/mL blood plasma; All other population groups: 10 ng PFOA/mL blood plasma; 20 ng PFOS/mL blood plasma.

Human Biomonitoring (HBM)-I values for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) - Description, derivation and discussion.

In 2016, the German Human Biomonitoring Commission (HBM-C) published a statement on its decision to develop HBM-I values for Perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic acid (PFOS) (Bundesgesundheitsbl 2016, 59:1364 DOI 10.1007/s00103-016-2437-1). The HBM-I value corresponds to the concentration of a substance in a human biological material below which no adverse health effects are expected, according to current knowledge and assessment by the HBM-C, and, consequently, there is no need for action. Evidence for associations between PFOA- and PFOS-body burden and health outcomes was found for fertility and pregnancy, weights of newborns at birth, lipid metabolism, immunity, sex hormones and age at puberty/menarche, thyroid hormones, onset of menopause as well as uric acid metabolism. Significant contrasts were reported for human blood plasma concentrations between 1 and 10 ng PFOA/mL, and 1-15 ng PFOS/mL, respectively. Within the reported ranges, the HBM-C has decided to set the HBM-I-values at 2 ng PFOA/mL and 5 ng PFOS/mL blood plasma. The underlying pathomechanisms do not appear to be sufficiently clarified to provide an unambiguous explanation of the effects observed. Consistency of toxicological and epidemiological data has been considered. The available data do not indicate an unequivocal proof of a genotoxicity of PFOA and PFOS.

Perfluorinated compounds in fish and blood of anglers at Lake Möhne, Sauerland area, Germany.

Perfluorinated compounds (PFCs) were measured in fish samples and blood plasma of anglers in a cross-sectional study at Lake Möhne, Sauerland area, Germany. Human plasma and drinking water samples were analyzed by solid phase extraction, high-performance liquid chromatography (HPLC), and tandem mass spectrometry (MS/MS). PFCs in fish fillet were measured by ion pair extraction followed by HPLC and MS/MS. PFOS concentrations in 44 fish samples of Lake Möhne ranged between 4.5 and 150 ng/g. The highest median PFOS concentrations have been observed in perches (median: 96 ng/g) and eels (77 ng/g), followed by pikes (37 ng/g), whitefish (34 ng/g), and roaches (6.1 ng/g). In contrast, in a food surveillance program only 11% of fishes at retail sale contained PFOS at detectable concentrations. One hundred five anglers (99 men, 6 women; 14-88 years old; median 50.6 years) participated in the human biomonitoring study. PFOS concentrations in blood plasma ranged from 1.1 to 650 µg/L (PFOA: 2.1-170 µg/L; PFHxS: 0.4-17 µg/L; LOD: 0.1 µg/L). A distinct dose-dependent relationship between fish consumption and internal exposure to PFOS was observed. PFOS concentrations in blood plasma of anglers consuming fish 2-3 times per month were 7 times higher compared to those without any fish consumption from Lake Möhne. The study results strongly suggest that human internal exposure to PFC is distinctly increased by consumption of fish from PFC-contaminated sites.

Prevalence of nickel sensitization and urinary nickel content of children are increased by nickel in ambient air.

In a cross-sectional study performed in 2000, an unexpected positive association between nickel (Ni) in ambient air, urinary Ni content and the prevalence of Ni sensitization in a subgroup of 6-yr-old children living near a steel mill was observed. Between 2005 and 2006, in a different and larger study population, we examined if Ni from ambient air or urinary Ni concentration was related to Ni sensitization in children living next to Ni-emitting steel mills. We studied 749 school beginners living in four Ni-polluted industrial areas of North Rhine-Westphalia, Germany. We assessed Ni in ambient air, Ni in urine from children and mothers, and Ni in tap water, conducted patch tests in children (including the NiSO(4)-dilution test) and collected questionnaire data. Statistics were done by linear and logistic regression analyses, adjusted for covariates. At increased Ni concentration in ambient air (unit of increase: 10 ng/m(3)), urinary Ni concentrations rose in both mothers (9.1%; 95% CI: 6.8-11.4%) and children (2.4%; 95% CI: 0.4-4.4%). The prevalence of Ni sensitization in children was associated with increased Ni from ambient air (unit of increase: 18 ng/m(3); odds ratio 1.28; 95% CI: 1.25-1.32) and urinary Ni concentration (unit of increase: 7.1 µg/L; odds ratio 2.4; 95% CI: 1.20-4.48). Ni in ambient air of areas with Ni-emitting factories contributes to internal Ni exposure in residents via inhalation and, furthermore, is a risk factor for the development of Ni sensitization in children.

Contribution to the evaluation of reference values for PFOA and PFOS in plasma of children and adults from Germany.

Perfluorinated compounds (PFC) are a large group of chemicals produced for several decades and widely used for many industrial and consumer applications. Human Biomonitoring studies reveal a background exposure of the general population to perfluorooctanoic acid (PFOA) and pefluorooctane sulfonate (PFOS) in many parts of the world. Reference values for PFOS and PFOA in the German population are currently not available. However, the data of three PFC human biomonitoring studies are taken as basis for deriving a preliminary reference value. The first two studies were performed in southern Germany with 105 (sampling period 2003-2004) and 356 adults (sampling period 2005). The third study was performed in North Rhine-Westphalia (sampling period October and November 2006) in connection with the high PFOA contamination of drinking water in the Sauerland region. Non PFOA exposed control groups comprised of 80 children and 153 females from Siegen and 103 men from Brilon. The whole study which could be taken as a basis for PFOS reference considerations comprised of 170 children, 317 females and 204 men. Though the studies are not representative for the German population, they provide at present the best available data basis for deriving reference values. The 95th percentile values of the studies were used and the following preliminary reference values are recommended: PFOA, 10microg/l for all groups; for PFOS 10microg/l for children at school beginner age, 15microg/l for adult females and 25microg/l for adult males.

Biomonitoring of perfluorinated compounds in children and adults exposed to perfluorooctanoate-contaminated drinking water.

OBJECTIVE: 40,000 residents in Arnsberg, Germany, had been exposed to drinking water contaminated with perfluorinated compounds (PFCs). Internal exposure of the residents of Arnsberg to six PFCs was assessed in comparison with reference areas. DESIGN AND PARTICIPANTS: One hundred seventy children (5-6 years of age), 317 mothers (23-49 years), and 204 men (18-69 years) took part in the cross-sectional study. MEASUREMENTS: Individual consumption of drinking water and personal characteristics were assessed by questionnaire and interview. Perfluorooctanoate (PFOA), perfluorooctanesulfonate (PFOS), perfluorohexanoate, perfluorohexanesulfonate (PFHxS), perfluoropentanoate, and perfluorobutanesulfonate (PFBS) in blood plasma and PFOA/PFOS in drinking water samples were measured by solid-phase extraction, high-performance liquid chromatrography, and tandem mass spectrometry detection. RESULTS: Of the various PFCs, PFOA was the main compound found in drinking water (500-640 ng/L). PFOA levels in blood plasma of residents living in Arnsberg were 4.5-8.3 times higher than those for the reference population (arithmetic means Arnsberg/controls: children 24.6/5.2 microg/L, mothers 26.7/3.2 microg/L, men 28.5/6.4 microg/L). Consumption of tap water at home was a significant predictor of PFOA blood concentrations in Arnsberg. PFHxS concentrations were significantly increased in Arnsberg compared with controls (p < 0.05). PFBS was detected in 33% of the children, 4% of the women, and 13% of the men in Arnsberg compared with 5%, 0.7%, and 3%, respectively, in the reference areas (p < 0.05). Regression analysis showed that age and male sex were significant predictors of PFOS, PFOA, and PFHxS; associations of other regressors (diet, body mass index) varied among PFCs. CONCLUSIONS: PFC concentrations in blood plasma of children and adults exposed to PFC-contaminated drinking water were increased 4- to 8-fold compared with controls.

Assessment and management of the first German case of a contamination with perfluorinated compounds (PFC) in the Region Sauerland, North Rhine-Westphalia.

In May 2006 the first serious German perfluorinated compounds (PFC) case of contamination became evident. Industrial waste with high concentrations of PFC was manufactured into a soil improver by a recycling company and spread by farmers on agricultural land of the rural area Sauerland, and led to substantial environmental pollution. In parts of the affected area, perfluorooctanoic acid (PFOA) concentrations in drinking water were > 0.5 microg/L. The German Drinking Water Commission assessed PFC in drinking water and set a health-based guidance value for safe lifelong exposure of all population groups at 0.3 microg/L (sum of perfluorooctane sulfonate [PFOS] and PFOA). The Ministry of Environment together with regional institutions initiated monitoring measurements and actions to minimize further contamination. A human biomonitoring study with mother-child pairs and men revealed that increased PFOA exposure via drinking water led to about four- to eightfold higher PFOA levels in plasma compared to nonexposed groups. Analysis of PFC in breast milk showed comparatively low levels, which seemed not to pose a risk for lactating infants. Due to high levels of PFOS in fish from contaminated lakes and rivers, recommendations for anglers to reduce fish consumption were initiated. Remediation of the affected area is ongoing and PFC levels in various matrices are still above background levels.

A comparative study of chemically induced DNA damage in isolated nasal mucosa cells of humans and rats assessed by the alkaline comet assay.

Single-cell microgel electrophoresis (comet) assay was used to study genotoxic effects in human nasal mucosa cells and rat nasal and ethmoidal mucosa cells in vitro. Human cells were obtained from tissue samples of 10 patients (3 females/7 males), who underwent surgery (conchotomy) for treatment of nasal airway obstruction. Rat nasal mucosa cells were derived from male Sprague-Dawley rats. Cells were exposed for 1 h to either N-nitrosodiethanolamine (NDELA), epichlorohydrin (EPI), 1,2-epoxybutane (EPB), ethylene dibromide (EDB), or 1,2-dibromo-3-chloropropane (DBCP). Dimethyl sulfoxide (DMSO) was used as negative control. Alkaline comet assay was performed according to a standard protocol and DNA damage was quantified as Olive tail moment using image analysis system. All test substances induced an increase in DNA damage in human and rat cells. The absolute amount of DNA damage in rat nasal mucosa cells was usually higher than in ethmoidal mucosa cells. Human nasal mucosa cells were found to be less sensitive than rat mucosa cells to the genotoxic activities of DBCP (lowest effective concentration in human cells [LEC(human)]: 1.5, in rat cells [LEC(rat)]: 0.01 mM) and NDELA (LEC(human): 25, LEC(rat): 12.5 mM), whereas EPB-treated cells were almost equal (LEC(human) and LEC(rat) 0.78 mM). NDELA induced a marked concomitant cytotoxicity. For EPI (LEC(human) and LEC(rat): 0.097 mM) and EDB (LEC(human): 0.195, LEC(rat): 0.048 mM), pronounced interindividual differences were observed in human samples.

Human biomonitoring studies in North Rhine-Westphalia, Germany.

The areas along the rivers Rhine, Ruhr and Wupper in North Rhine-Westphalia (NRW), Germany, represent the largest urban and industrial agglomeration in Europe with about 10 million inhabitants. Human biomonitoring (HBM) studies have been conducted in these areas since more than 30 years, mainly designed to evaluate internal exposure to air pollutants. Recent studies were focussed on residents living near industrial sources. The contaminants studied comprise heavy metals, metabolites of polycyclic aromatic hydrocarbons (PAH), persistent organic pollutants (POPs), volatile organic compounds (VOC), and markers of DNA exposure. Study groups were mainly children and elderly subjects. Human milk, blood, urine, teeth, hair and nails were investigated. Time trend analyses demonstrate a significant decline of exposure to many contaminants such as POPs and heavy metals. More recent studies suggest that there still is an increased internal exposure to metals, PAH and DNA damaging agents in children and women living very close to industrial sources.

Influence of industrial sources on children's health--hot spot studies in North Rhine Westphalia, Germany.

The aim of this study was to evaluate exposure and health outcome of children living close to industrial sources. Exposure and health outcome was assessed in nearly 1000 children at school beginner age living in the vicinity of industrial sources of three different hot spots (Duisburg North, Duisburg South and Dortmund Hörde) and in a rural area of North Rhine Westphalia (NRW), Germany. The cross-sectional study was undertaken between March and May 2000. Exposure assessment comprised modelling of ambient air quality data and human biomonitoring (HBM). Depending on the site-specific contaminants, HBM included the measurement of PAH (polycyclic aromatic hydrocarbons) and benzene metabolites in urine as well as heavy metals in blood and urine. Markers of early effects were DNA strand breaks as measured by the comet assay in lymphocytes and excretion of alpha-1-microglobuline and N-acetyl-beta-D-glucosamidase in urine. Health outcome was assessed by questionnaire, lung function test, dermatological examination as well as by RAST (radioallergosorbent test), patch tests and prick tests. The influence of exposure variables on biomarkers and health outcome was measured by means of multiple linear and logistic regression analysis. The most striking results were as follows. Children living close to a coke oven plant (Duisburg North) had increased levels of PAH metabolites in urine, and DNA exposure was increased. Children living at the Dortmund Hörde hot spot (increased chromium and nickel ambient air levels from a steel mill) revealed a high prevalence of allergic sensitizations. Sensitization, especially against nickel, was associated with the current internal nickel exposure, and nickel in ambient air was positively associated with the frequency of allergic symptoms. Children from the hot spot areas had increased specific airway resistance and total lung capacity as compared to those of the reference area. In Duisburg North particularly, specific airway resistance and total lung capacity significantly increased with increasing TSP (total suspended particulate). The only positive associations between external and internal exposure were found between benzo[a]pyrene in ambient air and 1-hydroxypyrene in urine, and between lead in ambient air and in the blood of the children. It is concluded that despite improvements of the general air quality during the last decades, living in the vicinity of industrial sources results to some extent in increased internal contaminant exposure and in effects on health outcome. Still ongoing studies are aimed to find out whether the increased PAH and DNA exposure of children from Duisburg North had decreased after the coke oven plant had been shut down in 2003, and if the striking results on the high prevalence of allergic sensitization can be confirmed by introducing an expanded cross-sectional study at four hot spots with increased chromium and nickel ambient air levels.

Recent experimental results of effects of perfluoroalkyl substances in laboratory animals - Relation to current regulations and guidance values.

The detection of perfluoroalkyl substances (PFAS) in surface and drinking water from various countries raised the attention to the presence of these chemicals in environmental probes and led to several regulatory actions to limit exposure in human beings. There was particular concern about perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), due to their former wide-spread use. Recently, several institutions published revisions of former regulatory or recommended maximum concentrations in drinking water and food, which are markedly lower than the former values. The present short overview describes the current regulations for PFAS and compares them with the outcome of several experimental studies in laboratory animals at low-level exposure to PFOA and PFOS. In addition, regulations for short-chain PFAS are presented which, due to lack of toxicological information, are evaluated according to the concepts of Threshold of Toxicological Concern (TTC) or the Health-related Indication Values (HRIV).

Human biomonitoring pilot study DEMOCOPHES in Germany: Contribution to a harmonized European approach.

Human biomonitoring (HBM) is an effective tool to assess human exposure to environmental pollutants, but comparable HBM data in Europe are lacking. In order to expedite harmonization of HBM studies on a European scale, the twin projects COPHES (Consortium to Perform Human Biomonitoring on a European Scale) and DEMOCOPHES (Demonstration of a study to Coordinate and Perform Human Biomonitoring on a European Scale) were formed, comprising 35 partners from 27 European countries. In COPHES a research scheme and guidelines were developed to exemplarily measure in a pilot study mercury in hair, cadmium, cotinine and several phthalate metabolites in urine of 6-11year old children and their mothers in an urban and a rural region. Seventeen European countries simultaneously conducted this cross-sectional DEMOCOPHES feasibility study. The German study population was taken in the city of Bochum and in the Higher Sauerland District, comprising 120 mother-child pairs. In the present paper features of the study implementation are presented. German exposure concentrations of the pollutants are reported and compared with European average concentrations from DEMOCOPHES and with those measured in the representative German Environmental Survey (GerES IV). German DEMOCOPHES concentrations for mercury and cotinine were lower than the European average. However, 47% of the children were still exposed to environmental tobacco smoke (ETS) outside their home, which gives further potential for enhancing protection of children from ETS. Compared with samples from the other European countries German participating children had lower concentrations of the phthalate metabolites MEP and of the sum of 3 DEHP-metabolites (MEHP, 5OH-MEHP and 5oxo-MEHP), about the same concentrations of the phthalate metabolites MBzP and MiBP and higher concentrations of the phthalate metabolite MnBP. 2.5% of the German children had concentrations of the sum of 4 DEHP-metabolites and 4.2% had concentrations of MnBP that exceeded health based guidance values, indicating reasons for concern. Continuous HBM is necessary to track changes of pollutant exposure over time. Therefore Germany will continue to cooperate on the harmonisation of European human biomonitoring to support the chemicals regulation with the best possible exposure data to protect Europe's people against environmental health risks.

Human biomonitoring of cadmium and lead exposure of child-mother pairs from Germany living in the vicinity of industrial sources (hot spot study NRW).

Cadmium (Cd) and lead (Pb) exposure of children and their mothers living in the vicinity of industrial sources (metal refining) was assessed by a cross-sectional study performed in 2000. Study areas were the highly industrialized city of Duisburg and a rural area of North Rhine Westphalia, Germany. Exposure to ambient air concentrations of Cd and Pb was calculated from a Lagrange dispersion model using data sets from ambient air quality measurements. Cd in blood and urine and Pb in blood were measured by AAS. Mean age (years) was 6.4 (range 5.5-7.7) for children (n = 238) and 36 (range 23-48) for mothers (n = 213). A total of 49% of the children were males. Factors suspected to influence metal levels in blood or urine were obtained by questionnaire. Individual ambient Cd and Pb levels according to the home address ranged from 0.5 ng/m3 (Cd) and 0.03 microg/m3 (Pb) (rural area) up to 31.2 ng/m3 (Cd) and 0.73 microg/m3 (Pb) (industrialized area). Cd levels (geometric mean) in blood (0.13 and 0.10 microg/L) and urine (both areas 0.09 microg/L) of children did not differ between the two areas. Cd levels in blood and urine of mothers from the industrialized area were higher (blood 0.39 microg/L, urine 0.28 microg/L) than in those from the rural area (blood 0.25 microg/L, urine 0.25 microg/L). Pb levels in the blood of children from the industrialized area were higher (31 microg/L) than in those from the rural area (21 microg/L). Pb levels in the blood of mothers did not differ between the two areas (both 24 microg/L). Pb levels in blood showed a significant association between child and mother (n = 192; r = 0.26, p < 0.001). This did not apply for Cd in blood or urine. Regression analysis clearly revealed that Pb levels in ambient air were associated with Pb in the blood of children. Minor associations were also found between Cd in air and Cd in the blood of mothers and between Cd in air and urine of mothers.

Perfluorinated compounds in the vicinity of a fire training area--human biomonitoring among 10 persons drinking water from contaminated private wells in Cologne, Germany.

In Cologne, Germany, increased concentrations of perfluorinated compounds (PFC) have been observed in two private wells used for drinking water purposes. Both wells are located in the vicinity of a fire training area. Use of well water as a source of drinking water was prohibited by the Public Health Department of the City of Cologne. A human biomonitoring (HBM) survey was performed among all persons, who consumed water from these private wells (N=10). PFC concentrations in water of the private wells and in blood samples were analysed by tandem mass spectrometry with electrospray ionization (LC-ESI-MS/MS). Repeated water analyses (seven measurements between December 2009 and November 2010) indicated a decrease of PFOS from 8.35 to 1.60 µg/l, (PFHxS: 2.36-0.15 µg/l; PFOA: 0.16-0.03 µg/l) in one private well. Although situated close together, PFC-concentrations in the other private well were significantly lower. PFOS-concentrations in blood samples of private well water consumers ranged from 4.8 to 295 µg/l (PFHxS: 12.1-205 µg/l; PFOA: 4.0-18 µg/l). Although no data on the formulation of the firefighting foams applied on the fire training area is available, firefighting foams are supposed to be the most likely source of contamination. These findings give reason to track systematically the application of PFC-containing firefighting foams in order to identify contaminations of surface, ground and drinking waters.

Two-year follow-up biomonitoring pilot study of residents' and controls' PFC plasma levels after PFOA reduction in public water system in Arnsberg, Germany.

Residents in Arnsberg, Germany, had been supplied by drinking water contaminated with perfluorooctanoate (PFOA). Biomonitoring data from 2006 evidenced that plasma PFOA concentrations of residents from Arnsberg were 4.5-8.3 times higher than those in reference groups. The introduction of charcoal filtration in July 2006 distinctly reduced PFOA concentrations in drinking water. Our one-year follow-up study showed a 10-20% reduction of PFOA plasma levels in residents from Arnsberg. Here we report the first results of the two-year follow-up study Arnsberg 2008. Additionally, the results of the two-year follow-up examination of the reference group are included. Paired plasma samples of 138 study participants (45 children, 46 mothers and 47 men) collected in 2006 and 2008 were considered in the statistical analyses. Within the two years plasma concentrations of PFOA, perfluorooctanesulfonate (PFOS) and perfluorohexanesulfonate (PFHxS) decreased in residents from Arnsberg and in control groups. The geometric means of PFOA plasma levels declined by 39% (children and mothers) and 26% (men) in Arnsberg and by 13-15% in the corresponding subgroups from the reference areas. For the population from Arnsberg a geometric mean plasma PFOA half-life of 3.26 years (range 1.03-14.67 years) was calculated. Our results confirm an ongoing reduction of the PFOA load in residents from Arnsberg. The decline of PFC levels in plasma of participants from the reference areas reflects the general decrease of human PFC exposure during the very recent years.

Preliminary observations on perfluorinated compounds in plasma samples (1977-2004) of young German adults from an area with perfluorooctanoate-contaminated drinking water.

In May 2006, a serious environmental contamination with perfluorinated compounds (PFCs) became evident in a rural area of North Rhine-Westphalia (NRW) (Region Sauerland), Germany. In autumn 2006, we performed a human biomonitoring study in which a 4-8-fold increase in perfluorooctanoate (PFOA)-plasma concentrations of children, their mothers and men living in Arnsberg (District Hochsauerlandkreis, NRW) was observed compared with a reference population. The exposure was clearly related to the consumption of PFOA-contaminated tap water. However, there is no clear information on the duration of this contamination. The current investigation involves the analysis of PFCs in 30 blood samples of young adults (age 20-31 years) who had ever lived in the affected area. The samples were taken between 1977 and 2004 and stored at the German Environmental Specimen Bank for Human Tissues. Analyses of PFOA, perfluoroctanesulfonate (PFOS), perfluorohexanoate (PFHxA), perfluorohexanesulfonate (PFHxS), perfluoropentanoate (PFPA) and perfluorobutanesulfonate (PFBS) in blood plasma were performed by solid-phase extraction, HPLC and MS/MS detection. PFOA values (median, range) were 6.1, 1.7-40.7 microg/l, PFOS values were 18.8, 8.1-150.7 microg/l and PFHxS values were 1.7, 0.5-4.6 microg/l. The concentrations of PFHxA, PFPA and PFBS in plasma were all below limit of detection. Time-trend analysis showed that between 1977 and 2004 PFOA and PFOS levels remained fairly stable. PFOS and PFOA levels were in the range of current background levels of the general population. In contrast, PFHxS plasma levels have steadily increased since 1977. There was a close association between PFOS and PFOA-plasma levels. From this pilot study there are no indications for an increased exposure to PFCs of residents in Arnsberg in the years 1977-2004 prior to the contamination in 2006.

One-year follow-up of perfluorinated compounds in plasma of German residents from Arnsberg formerly exposed to PFOA-contaminated drinking water.

In Arnsberg, Sauerland area Germany, 40000 residents were exposed to PFOA-contaminated drinking water (500-640ng PFOA/l; May 2006). In July 2006, the PFOA-concentrations in drinking water were lowered significantly by activated charcoal filtering in the waterworks, mostly below the limit of detection (10ng/l). A first human biomonitoring study performed in autumn 2006 revealed that PFOA-concentrations in blood plasma of residents living in Arnsberg were 4.5-8.3 times higher than in the reference groups. One year after the first survey, all participants (2006: 164 mothers, 90 children, 101 men) were invited to take part in a follow-up study. It was the aim of the study to determine the decline of the PFOA-concentrations in blood plasma. 288 persons (81%) were included in the statistical analysis. The (geometric) mean PFOA-concentrations in blood plasma of Arnsberg's residents decreased from 22.1 to 17.4 microg/l in children, from 23.4 to 18.8 microg/l in mothers and from 25.3 to 23.4 microg/l in men within one year. The average (geometric mean) changes in each individual's PFOA-concentrations were approximately 10 (men), 17 (mothers) and 20 (children) percent/year. The observed decline in PFOA-concentrations indicates a slow elimination in humans. This finding in groups of the general population is in agreement with data on long elimination half-lives observed in occupationally exposed workers.