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- Järnberg, Ulf, et al.
(författare)
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Perfluoroalkylated acids and related compounds (PFAS) in the Swedish environment
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The perfluoroalkylated substances have gained increased attention among scientists and regulators during the last few years. In particular, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and similar perfluorinated alkylated acids are regarded as the most stable end products of various perfluoroalkylated substances and have been shown to be extremely stable, bioconcentrate and biomagnify and have several toxicological effects. The industrial chemistry of perfluoroalkylated substances is extremely diverse and includes almost all chemical functionalities from simple pure alkanes to complex co-polymers. Major usage of perfluoroalkylated products is related to polymeric compounds and the dominant release to the environment is from primary and secondary production plants which are lacking in the Nordic countries. The occurrence of elevated concentrations of perfluoroalkylated acids in Sweden is strongly related to urbanized areas and the most likely path into the aquatic environment is through sewage water, although atmospheric input is also possible via more volatile precursor compounds. Up to 40 times elevated concentrations were found in biota from urban areas compared to unpolluted areas. Lake Mälaren and lower parts of the river Helge å are examples of aqueous environments clearly contaminated by PFOS. One of several potential point sources in Sweden has been screened for PFOS. A firefighting training site was found to release PFOS to the local aqueous environment (wetland) where μg/l concentrations where found. Long chain (more than 8 C for sulfonates and 10 C or more for carboxylates) perfluoroalkylated acids are readily taken up by biota in aqueous environments and reach very high concentrations in predators at high trophic levels of aquatic food webs. Baltic guillemot egg showed an increasing trend in PFOS concentration from 20-30 ng/g by the end of sixties to more than 600 ng/g at present. Freshwater otter from various locations in Sweden showed concentrations similar to guillemot eggs and Baltic grey seal has extreme values up to ten times higher (21 μg/g sum of all acids 6-14 C, PFOS alone:11μg/g). Human exposure, as described by Swedish human blood levels, appears to be similar to most other countries. No extreme values were encountered which would indicate occupational exposure. An excessive consumption of freshwater fish may contribute to an increased exposure, but this could not be clearly verified. Occupational settings where exposure to precursor compounds can take place are present in Sweden and should be included in future studies. Industrial use of textile and leather impregnating formulations result in elevated concentrations of perfluorocarboylates in effluent water from sewage treatment plants. The relation between effluent and biota concentrations for an aquatic environment with this type of activity needs to be further described in particular for perfluoroalkyl carboxylates which are currently being discharged in Sweden. Exposure routes and distribution behavior are yet not completely described for many PFAS, in particular their precursors. Environmental levels, human levels and human exposure data are lacking for a wide variety of PFAS discussed in this report
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