Analysis of PFAS in ash from incineration facilities from Sweden

Abstract: Per- and polyfluoroalkyl substances (PFAS) are a group of organohalogens that bioaccumulate in biota, have toxicological effects and are persistent in the environment. Because of the fluorinated carbon chain, PFASs are present in many household and industrial products. The aim of this study is to investigate if PFASs are residues in ash from municipality incineration facilities and asses if the ashes can become a source of environmental pollution. In the method development three different extraction methods were tested (liquid-solid extraction with MeOH, liquid-solid extraction with acetone/hexane and Soxhlet extraction with MeOH) and evaluated by quantification of PFASs and extractable organic fluorine (EOF). The liquid-solid extraction with MeOH was chosen as the extraction method as the target PFASs were extracted from the ash samples while the other methods resulted in lower signals. The EOF had high blank raising questions about the suitability of the method for EOF. The results from analysing ashes from 11 facilities sampled in 2005 indicate that PFASs are occurring more often in fly ash than bottom ash (sum of PFAS 43,1- 950,7 pg/g) however the two samples with the highest detected amount of PFASs (1611 and 7169,5 pg/g) were both bottom ash. The PFASs that were found in the highest concentrations were at low parts per billion in concentration levels. Since the landfill sites around waste facilities are continuously refilled with new ash from the incineration there is a possibility that the landfills could become a source of environmental pollution in the future with continuously leeching from the added ashes.