Long-term trend data for PFAS in soils from German ecosystems, including TOP assay.

In this study, soil top layers from the German Environmental Specimen Bank (ESB) covering a period from 2002 to 2018 and 11 sampling sites representing four ecosystem types were analysed for 24 PFAS (11 PFCA, 7 PFSA, and 6 precursors), including the total oxidizable precursor (TOP) assay. Median ΣPFAS levels before and after TOP assay ranged from 0.31 to 19.7 µg/kg dry weight (dw) and 0.32 to 20.4 µg/kg dw, respectively. The most frequently measured PFAS above LOQ were PFOS and PFOA, which were present at concentrations above 0.1 µg/kg dw in each sample. Both accounted, on average, for half to two-thirds of the total identified PFAS load at most sites. The investigated samples from the near-natural and forestry ecosystem types each had significantly higher PFAS levels than those from the urban-industrial ecosystem type, while samples from the agricultural ecosystem type did not differ distinctly from the others. Increases of median ΣPFAS levels after TOP assay ranged up to slightly >20 %, indicating that precursor compounds do not play a major role in the substance spectrum of German ESB soil samples from different ecosystem types. Total organic carbon (TOC) content in analysed samples ranged from about 1 % in sandy soil to >40 % in litter layer and showed a strong positive correlation with PFAS concentrations. It is therefore highly recommended that TOC content is reported along with PFAS levels in soils. PFAS trend analysis for nine sampling sites before and after TOP assay showed that concentration levels at most sites have remained more or less stable for the sampled period of almost two decades. The constant PFAS levels in soil samples indicate that PFOS and PFOA regulations have not yet had a positive effect on the exposure situation in this environmental compartment.

Perfluoroalkyl substances (PFAS) adsorption in drinking water by granular activated carbon: Influence of activated carbon and PFAS characteristics.

Perfluoroalkyl substances (PFAS) persistence in the environment leads to their presence in drinking water, that is of high concern due to their potential human health risk. Adsorption onto activated carbon (AC) has been identified as an effective technique to remove PFAS. Adsorption isotherms and breakthrough curves, determined by rapid small-scale column tests (RSSCTs), were studied for eight PFAS and four granular ACs, characterized by different origins, porosities and numbers of reactivation cycles. Both batch and RSSCT results highlighted the strong interaction of AC and PFAS characteristics in adsorption capacity. The most important factor affecting AC performance is the surface charge: a positively-charged AC showed higher adsorption capacities with greater Freundlich constants (KF) and later 50% breakthroughs compared to the AC with neutral surface. Among the positively-charged ACs, a microporous AC demonstrated higher adsorption capacities for hydrophilic and marginally hydrophobic PFAS, while the mesoporous AC performed better for more hydrophobic PFAS, possibly due to lower pore blockage by organic matter. These results were confirmed at full-scale through a one-year monitoring campaign, in which samples were collected at the inlets and outlets of GAC systems in 17 drinking water treatment plants spread in a wide urban area, where the four analyzed ACs are used.

Per- and polyfluoroalkyl substances in blood plasma - Results of the German Environmental Survey for children and adolescents 2014-2017 (GerES V).

The 5th cycle of the German Environmental Survey (GerES V) investigated the internal human exposure of children and adolescents aged 3-17 years in Germany to per- and polyfluoroalkyl substances (PFAS). The fieldwork of the population-representative GerES V was performed from 2014 to 2017. In total, 1109 blood plasma samples were analysed for 12 PFAS including perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonic acid (PFHxS). PFOS was quantified in all and PFOA in almost all samples, demonstrating ubiquitous exposure. The highest geometric mean concentrations measured were 2.49 ng/mL for PFOS, followed by PFOA (1.12 ng/mL) and PFHxS (0.36 ng/mL), while concentrations of other PFAS were found in much lower concentrations. The 95th percentile levels of PFOS and PFOA were 6.00 and 3.24 ng/mL, respectively. The results document a still considerable exposure of the young generation to the phased out chemicals PFOS and PFOA. The observed exposure levels vary substantially between individuals and might be due to different multiple sources. The relative contribution of various exposure parameters such as diet or the specific use of consumer products need to be further explored. Although additional investigations on the time trend of human exposure are warranted, GerES V underlines the need for an effective and sustainable regulation of PFAS as a whole.

Biota monitoring and the Water Framework Directive-can normalization overcome shortcomings in sampling strategies?

We compare the results of different monitoring programs regarding spatial and temporal trends of priority hazardous substances of the European Water Framework Directive (WFD). Fish monitoring data for hexachlorobenzene (HCB), mercury (Hg), and perfluorooctane sulfonic acid (PFOS) sampled in German freshwaters between the mid-1990s and 2014 were evaluated according to the recommendations of the 2014 adopted WFD guidance document on biota monitoring, i.e., normalization to 5 % lipid content (HCB) or 26 % dry mass (Hg, PFOS) and adjustment to trophic level (TL) 4. Data of the German Environmental Specimen Bank (ESB) (annual pooled samples of bream) were compared to monitoring data of the German federal states (FS), which refer to individual fish of different species. Significant decreasing trends (p < 0.01) were detected for Hg in bream (Abramis brama) sampled by both, the ESB and the FS between 1993 and 2013 but not for FS samples comprising different fish species. Data for HCB and PFOS were more heterogeneous due to a smaller database and gave no consistent results. Obviously, normalization could not compensate differences in sampling strategies. The results suggest that the data treatment procedure proposed in the guidance document has shortcomings and emphasize the importance of highly standardized sampling programs in trend monitoring or whenever results between sites have to be compared.

Current levels and trends of selected EU Water Framework Directive priority substances in freshwater fish from the German environmental specimen bank.

Under the German environmental specimen bank programme bream (Abramis brama) were sampled in six German rivers and analysed for the priority hazardous substances dicofol, hexabromocyclododecane (HBCDD), hexachlorobenzene (HCB), hexachlorobutadiene (HCBD), heptachlor + heptachlor epoxide (HC + HCE), polybrominated diphenylethers (PBDEs), polychlorinated dibenzo-p-dioxins and -furans and dioxin-like polychlorinated biphenyls (PCDD/Fs + dl-PCBs), and perfluorooctane sulfonic acid (PFOS). The aim was to assess compliance with the EU Water Framework Directive environmental quality standards for biota (EQSBiota) for the year 2013, and to analyse temporal trends for those substances that are of special concern. General compliance was observed for dicofol, HBCDD and HCBD whereas PBDEs exceeded the EQSBiota at all sites. For all other substances compliance in 2013 varied between locations. No assessment was possible for HC + HCE at some sites where the analytical sensitivity was not sufficient to cover the EQSBiota. Trend analysis showed decreasing linear trends for HCB and PFOS at most sampling sites between 1995 and 2014 indicating that the emission reduction measures are effective. Mostly decreasing trends or constant levels were also observed for PCDD/Fs and dl-PCBs. In contrast, increasing trends were detected for PBDEs and HBCDD which were especially pronounced at one Saar site located downstream of the industries and conurbation of Saarbrücken and Völklingen. This finding points to new sources of emissions which should be followed in the coming years.

The use of monitoring data in EU chemicals management--experiences and considerations from the German environmental specimen bank.

Since the 1970s, environmental specimen banks (ESB) have emerged in many countries. Their highly standardised sampling and archiving strategies make them a valuable tool in tracing time trends and spatial distributions of chemicals in ecosystem compartments. The present article intends to highlight the potential of ESBs for regulatory agencies in the European Union (EU). The arguments are supported by examples of retrospective monitoring studies conducted under the programme of the German ESB. These studies have evaluated the success of regulatory and industry provisions for substances of concern (i.e. PCB, polybrominated diphenyl ethers, perfluorinated compounds, alkylphenol compounds, organotin compounds, triclosan/methyl-triclosan, musk fragrances). Time trend studies revealed for example that levels of organotin compounds in marine biota from German coastal waters decreased significantly after the EU had decided on a total ban of organotin-based antifoulings in 2003. Similarly, concentrations of commercially relevant congeners of polybrominated diphenyl ethers decreased in herring gull eggs from the North Sea only after an EU-wide ban in 2004. The data presented demonstrate the usefulness of ESB samples for (retrospective) time trend monitoring and underline the benefit of a more intensive cooperation between chemicals management and specimen banking.

Mercury levels and trends (1993-2009) in bream (Abramis brama L.) and zebra mussels (Dreissena polymorpha) from German surface waters.

Mercury concentrations have been analysed in bream (Abramis brama L.) and zebra mussels (Dreissena polymorpha) collected at 17 freshwater sites in Germany from 1993-2009 and 1994-2009, respectively, within the German Environmental Specimen programme. Mercury concentrations in bream ranged from 21 to 881 ng g(-1) wet weight with lowest concentrations found at the reference site Lake Belau and highest in fish from the river Elbe and its tributaries. Statistical analysis revealed site-specific differences and significant decreasing temporal trends in mercury concentrations at most of the sampling sites. The decrease in mercury levels in bream was most pronounced in fish from the river Elbe and its tributary Mulde, while in fish from the river Saale mercury levels increased. Temporal trends seem to level off in recent years. Mercury concentrations in zebra mussels were much lower than those in bream according to their lower trophic position and varied by one order of magnitude from 4.1 to 42 ng g(-1) wet weight (33-336 ng g(-1) dry weight). For zebra mussels, trend analyses were performed for seven sampling sites at the rivers Saar and Elbe of which three showed significant downward trends. There was a significant correlation of the geometric mean concentrations in bream and zebra mussel over the entire study period at each sampling site (Pearson's correlation coefficient=0.892, p=0.00002). A comparison of the concentrations in bream with the environmental quality standard (EQS) of 20 ng g(-1) wet weight set for mercury in biota by the EU showed that not a single result was in compliance with this limit value, not even those from the reference site. Current mercury levels in bream from German rivers exceed the EQS by a factor 4.5-20. Thus, piscivorous top predators are still at risk of secondary poisoning by mercury exposure via the food chain. It was suggested focusing monitoring of mercury in forage fish (trophic level 3 or 4) for compliance checking with the EQS for biota and considering the age dependency of mercury concentrations in fish in the monitoring strategy.