Stoffmonographie Pentachlorphenol-Referenz- und Human-Biomonitoring-Werte (HBM)

Non-destructive, solvent-free quantification of wood preservatives in wood flour and wooden objects using GC-DTIMS

Qualitative and quantitative on-site detection methods for wood preservatives are of high value for the recycling industry and the occupational health and safety. Wood preservatives revealed as toxic to human and environment after decades of use. For the detection of contaminated wood and for processing of matured timber to particle boards a versatile detection method is needed. Especially historical wooden objects were treated with preservatives like pentachlorophenol, lindane or dichlorodiphenyltrichloroethane. This requires a non-destructive on-site detection method, that does not require specialized personnel. In this publication two methods are presented utilizing headspace sampling by solid-phase microextraction, subsequent separation using gas chromatography and detection by a drift tube ion mobility spectrometer (SPME-HS-GC-DTIMS). One method enables the quantitative detection of pentachlorophenol in wood flour and wood chips as they are used in wood processing industries. A limit of detection of 0.1 mg/kg was achieved using DIN 32645, which can be even more lowered. The second method enables non-destructive detection of pentachlorophenol, lindane, dichlorodiphenyltrichloroethane and other preservatives in wooden objects. Therefore, samples were prepared, which show a significantly lower concentration than typical treated objects, and used next to real samples for method validation. With the method contamination of the real samples and of the prepared samples of low concentration were proven.

Urinary pentachlorophenol in general population of central China: reproducibility, predictors, and associations with oxidative stress biomarkers

Pentachlorophenol (PCP) is a ubiquitous environmental persistent organic pollutant and a Group 1 carcinogen. Human exposure level of PCP was reported to be relatively higher in China than in many other countries, because sodium pentachlorophenate was abused as molluscicide in China. PCP can induce oxidative stress; however, the relationship of PCP exposure with oxidative stress biomarkers (OSBs) in human beings has rarely been documented. In this study, 404 first-morning urine samples (including repeated samples in three days donated by 74 participants) were collected from 128 healthy adults (general population without occupational exposure to PCP) in autumn and winter of 2018, respectively, in Wuhan, central China. Urinary concentrations of PCP and three select OSBs [including 8-OHG (abbreviation of 8-hydroxy-guanosine), 8-OHdG (8-hydroxy-2'-deoxyguanosine), and 4-HNEMA (4-hydroxy-2-nonenal mercapturic acid), which reflect oxidative damage of RNA, DNA, and lipid, respectively] were determined. PCP was detectable in 100% of the urine samples (specific gravity-adjusted median concentration: 0.44 ng/mL; range: 0.02-14.2 ng/mL). Interday reproducibility of urinary PCP concentrations was excellent (intraclass correlation coefficient: 0.88) in three days. Significant differences in PCP concentrations were found among different age groups; the group of participants aged 20-45 y (median: 0.72 ng/mL) had higher concentrations than those in the elders (aged 45-60 y and > 60 y). Spatial disparity was observed in autumn, and urban residents had higher PCP concentrations than rural residents (median: 0.60 vs. 0.31 ng/mL), whereas such disparity was not found in winter. There were no season-, sex-, or BMI-related differences between the corresponding subgroups. The urinary PCP concentrations were found to be associated with increases in 8-OHdG and 8-OHG rather than 4-HNEMA. An interquartile range increase in urinary PCP concentration was associated with a 23.5% (95% CI: 9.18-39.6) increase in 8-OHdG and a 21.3% (95% CI: 9.18-32.4) increase in 8-OHG, implied that PCP exposure at environmental relevant dose might be associated with nucleic acid oxidative damage in the general population. This pilot study reported associations between PCP exposure and OSBs in human beings. Future studies are needed to elucidate the mediating roles of OSBs in the association between PCP exposure and certain adverse health outcomes.

Concept for the Evaluation of Carcinogenic Substances in Population-Based Human Biomonitoring

The Human Biomonitoring (HBM) Commission at the German Environment Agency holds the opinion that for environmental carcinogens for which no exposure levels can be assumed and are harmless to health, health-based guidance values corresponding to the classical definition of the HBM-I or HBM-II value cannot be established. Therefore, only reference values have been derived so far for genotoxic carcinogens from exposure data of the general population or subpopulations. The concept presented here opens up the possibility of performing health risk assessments of carcinogenic substances in human biomonitoring, and thus goes decisively beyond the purely descriptive statistical reference value concept. Using the presented method, quantitative dose descriptors of internal exposure can be derived from those of external exposure, provided that sufficient toxicokinetic information is available. Dose descriptors of internal exposure then allow the simple estimate of additional lifetime cancer risks for measured biomarker concentrations or, conversely, of equivalent concentrations for selected risks, such as those considered as tolerable for the general population. HBM data of chronic exposures to genotoxic carcinogens can thus be used to assess the additional lifetime cancer risk referring to the general population and to justify and prioritize risk management measures.

New approaches in human health risk assessment

Studies on the precise impact of environmental pollutants on human health are difficult to undertake and interpret, because many genetic and environmental factors influence health at the same time and to varying degrees. Our chapter in the AMAP report was based on new approaches to describe risks and future needs. In this paper, we will introduce the issues associated with risk assessment of single chemicals, and present suggestions for future studies as well as a summary of lessons learned during the health-related parts of the European Union-funded FP7 project ArcRisk (Arctic Health Risks: Impacts on health in the Arctic and Europe owing to climate-induced changes in contaminant cycling, 2009–2014; www.arcrisk.eu).

Revised reference value for pentachlorophenol in morning urine

Reference values are continuously derived by the Human Biomonitoring Commission of the German Federal Environment Agency to give help in assessing the exposure of individuals or population groups in comparison to the background exposure. As environmental conditions may change reference values should be checked periodically and they have to be updated, if new data become available. The results of the German Environmental Survey 1998 (GerES III) showed the decreasing pentachlorophenol (PCP) exposure of the German adult population. Therefore, the reference value for PCP in morning urine was lowered: from 8 to 5 microg/l for adults (aged 18-69 years) living in homes where wood preservatives had not been used.

Twenty years of the German Environmental Survey (GerES): Human biomonitoring – Temporal and spatial (West Germany/East Germany) differences in population exposure

The German Environmental Surveys (GerESs) are nationwide population studies, which have repeatedly been carried out in Germany since the mid-1980s. The subjects were representatively selected from the regional registration offices with regard to age, gender and community size. The first survey for adults (GerES I) was carried out in 1985/1986 (West Germany) followed by GerES IIa in 1990/1991 (West Germany) and GerES IIb in 1991/1992 (East Germany). In GerES II children were also included to some extent. In 1998, the third GerES for adults was conducted in both parts of Germany (GerES III). The current survey 2003/2006 (GerES IV) is focussing exclusively on children. A 1-year pilot study was conducted in 2001-2002 to collect information on parameters influencing the response rate and to test the suitability of the different instruments intended to be used for the main study. The main goal of the surveys is to analyse and document the extent, distribution and determinants of exposure to environmental pollutants of the German general population. Three main instruments of investigation were comprised in GerES: human biomonitoring (HBM), monitoring of the domestic environment, and collecting information on exposure pathways and living conditions via questionnaires. This paper is focussed on the general design of the GerESs, the trend over time and spatial differences (West Germany and East Germany) for HBM data on arsenic, cadmium, lead, mercury, pentachlorophenol (PCP), and polycyclic aromatic hydrocarbons (PAH). These substances have been determined in blood and/or morning urine of adults and children. All GerESs have been conducted in close connection with the National Health Interview and Examination Surveys performed by the Robert Koch-Institute, Berlin.

Urinary pentachlorophenol in painters and bricklayers in a four-years time interval after the PCP prohibition ordinance in Germany

Pentachlorophenol (PCP) was widely used as a wood preservative in Germany until 1989, when it was prohibited by law. Within a cross-sectional study we investigated the internal PCP exposure of painters and bricklayers between one year and four years after the ban. PCP was analysed in post-shift urine samples of 189 painters and 148 bricklayers by gas chromatography and electron capture detection (GC-ECD). The median PCP concentration in the urine of painters was 2.4 microg/g creatinine (range: 0.2-52 microg/g creatinine). For the bricklayers a range of 0.1-25 microg/g creatinine (median: 1.8 microg/g creatinine) was determined. The difference between both groups was statistically significant, pointing to a small additional uptake of PCP by the painters probably from an exposure to contaminated wood surfaces or residual PCP containing preservatives. The biomonitoring results for both groups coincided with background values of the general population at that time.

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.

Myeloperoxidase-catalyzed formation of PCDD/F from chlorophenols

Chlorophenols (CP) are transformed in vitro to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) by a biochemical-catalyzed oxidation. This is shown for 2,4,5-tri-, 2,3,4,6-tetra-and pentachlorophenol with myeloperoxidase recovered from human leucocytes in the presence of hydrogen peroxide. The yield, the reaction, and the PCDD/F-pattern found depend on the CP. The formation rates are in the micromol-per-mol range for all substrates. The experiments confirm the suspicion that a biochemical formation of PCDD/F from precursors such as CPs can take place in the human body and that this metabolic pathway may lead to a higher inner exposure with PCDD/F than is now assumed.