April 8 2019
The report is about a screening analysis of poly- and perfluoroalkyl substances (PFAS) and extractable organic fluorine (EOF) in samples from the Nordic environment performed by a group of Swedish and Norwegian scientists.
The project was financed by the Nordic Council of Ministers and followed by a Nordic Screening Group. The report can be downloaded from: http://norden.diva-portal.org/smash/get/diva2:1296387/FULLTEXT01.pdf
The report describes the screening of an extensive list of conventional and emerging per- and polyfluoroalkyl substances (PFAS) in the Nordic environment. PFAS belongs to a large class of substances that have become an environmental problem due to extreme persistence and potential toxic effects in biota and humans (see for instances other News articles).
More than 4 000 PFASs are estimated to be in circulation on the global market, and the environmental distribution is poorly understood. The most known PFAS are perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), which have been replaced in recent years. Their substitutes are often other PFAS, usually with shorter chain lengths or containing other functional groups
This screening study analyzed in total 99 different PFAS in 102 samples of which the majority of samples were collected in 2017 from a wide variety of environmental matrices, including bird eggs, fish, marine mammals, terrestrial mammals, surface water, WWTP effluents and sludge, and air from the Nordic countries. PFAS were analyzed using liquid-, supercritical fluid-, and gas chromatography coupled to mass spectrometry.
In addition, the samples were analyzed for extractable organic fluorine (EOF). EOF was analyzed using combustion ion chromatography. The EOF results can provide the amount of organofluorine in the samples, but will say nothing about the identity of the fluorochemicals contained, which not all will be PFAS. The EOF results can be used to estimate the mass balance between known and unknown organofluorine compounds.
Some preliminary results from the limited number of samples:
- Seabird eggs from Sweden had higher PFAS concentrations (up to 707 ng/g ww) than from Iceland and Faroe Island.
- It was confirmed, that Polar Bear liver from Greenland had extremely high PFAS concentrations (up to 1890 ng/g ww).
- Seals from Denmark had high PFAS concentrations (up to 123 ng/g ww).
- Reindeer liver from Greenland had higher PFAS concentration (5.4 ng/g ww) than from Sweden, Iceland and Finland.
- In livers from marine fish PFAS levels were up to 18 ng/g ww. The levels in freshwater fishes were much higher, and highest in perch from Finland (up to 302 ng/g ww).
Sewage sludge samples were dominated by PFCA precursors, on average accounting for 75% of all identified PFASs, and mainly contributed by different isomers of polyfluoroalkyl phosphoric acid diesters (diPAPs). The highest concentrations (149 ng/g dw) were found I Denmark. The highest effluent concentration was found in Sweden (113 ng/L).
The PFASs in surface water mainly ranged between 1 and 10 ng/L with one exception of 61 ng/L in Helsinki, Finland, which could indicates a strong influence from point source(s).