Auflistung nach Autor:in "Berger, Urs"

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Assessment of persistence, mobility and toxicity (PMT) of 167 REACH registered substances
(2018) Berger, Urs; Ost, Norbert; Neumann, Michael; Sättler, Daniel; Schliebner, Ivo; Helmholtz-Zentrum für Umweltforschung; Deutschland. Umweltbundesamt
For the first time a comprehensive list of 167 ⁠REACH⁠ registered substances were assessed with respect to their intrinsic substance properties persistence in the aquatic environment, mobility in the aquatic environment and toxicity. The results of this project will support the ongoing discussion to define PMT criteria under REACH. The present study provides a consolidated list of (in order of priority) assessed PaqMT substances (9 substances), assessed PaqM substances with suspected T (20 substances) and further 93 suspected PaqMT substances. A total of 134 substances are recommended to the German Environment Agency (⁠UBA⁠) for further investigation and scientific and regulatory scrutiny.
Comprehensive target analysis and TOP assay of per- and polyfluoroalkyl substances (PFAS) in wild boar livers indicate contamination hot-spots in the environment
(2023) Rupp, Jana; Guckert, Marc; Drost, Wiebke; Berger, Urs; Schulze, Jona
The suitability of wild boar liver as a bioindicator of per- and polyfluoroalkyl substances (PFAS) in the terrestrial environment was investigated. Samples from 50 animals in three different areas associated with (1) contaminated paper sludges distributed on arable land (PS), (2) industrial emissions of PFAS (IE) and (3) background contamination (BC) were analyzed for 66 PFAS, including legacy PFAS, novel substitutes and precursors of perfluoroalkyl acids (PFAAs). Additionally, the Total Oxidizable Precursor (TOP) assay was performed to determine the formation potential of PFAAs from precursors. In total, 31 PFAS were detected with site-specific contamination profiles. PFAS concentrations in livers from area PS and IE (567 and 944 (micro)g kg-1 wet weight, respectively) were multiple times higher than from area BC (120 (micro)g kg-1). The dominating PFAS were the legacy compounds perfluorooctane sulfonic acid (PFOS) in areas PS and BC (426 and 82 (micro)g kg-1, respectively) and perfluorooctanoic acid (PFOA) in area IE (650 (micro)g kg-1). In area IE, the compounds 4,8-dioxa-3H-perfluorononanoic acid (DONA) and hexafluoropropylene oxide dimer acid (HFPO-DA) - which are used as substitutes for PFOA - were determined at 15 and 0.29 (micro)g kg-1, respectively. The formation potential of PFAAs was highest in area PS, but generally lower than the contamination with PFAAs. The pattern of perfluoroalkyl carboxylic acids (PFCAs) in wild boar liver reflects the contamination of the local soil at the two hot-spot areas IE and PS. This first comparison of PFAS contamination between wild boars and soil suggests that wild boar livers are suitable bioindicators for PFAS contamination in the terrestrial environment. Moreover, in terrestrial samples from area IE, legacy PFAS were found to be retained for a longer period as compared to riverine samples (suspended particulate matter and chub filet). © 2023 The Authors
Estimation of the Acid Dissociation Constant of Perfluoroalkyl Carboxylic Acids through an Experimental Investigation of their Water-to-Air Transport
(2013) Berger, Urs; Cousins, Ian T.; Vierke, Lena
The acid dissociation constants (pKas) of perfluoroalkyl carboxylic acids(PFCAs) have been the subject of discussion in the literature; for example, values from-0.2 to 3.8 have been suggested for perfluorooctanoic acid (PFOA). The dissociatedanionic conjugate bases of PFCAs have negligible air-water partition coefficients (KAWs)and do not volatilize from water. The neutral acids, however, have relatively high KAWsand volatilization from water has been demonstrated. The extent of volatilization ofPFCAs in the environment will depend on the water pH and their pKa. Knowledge ofthe pKas of PFCAs is therefore vital for understanding their environmental transport and fate. We investigated the water-to-airtransfer of PFCAs in a novel experimental setup. We used ~1 ìg L-1 of PFCAs in water (above environmental backgroundconcentrations but below the concentration at which self-association occurs) at different water pH (pH 0.3 to pH 6.9) andsampled the PFCAs volatilized from water during a 2-day experiment. Our results suggest that the pKas of C4-11 PFCAs are <1.6.For PFOA, we derived a pKa of 0.5 from fitting the experimental measurements with a volatilization model. Perfluoroalkanesulfonic acids were not volatilized, suggesting that their pKas are below the investigated pH range (pKa <0.3).
Quelle: http://pubs.acs.org/
The acid dissociation constant of perfluoroalkyl carboxylic acids - estimated by an experimental investigation of their water-to-air transport
(2013) Vierke, Lena; Berger, Urs; Cousins, Ian T.
The acid dissociation constants of perfluoroalkyl carboxylic acids are <1.6
(2013) Vierke, Lena; Berger, Urs; Cousins, Ian T.