Toward a Comprehensive Global Emission Inventory of C4-C10Perfluoroalkanesulfonic Acids (PFSAs) and Related Precursors: Focus on the Life Cycle of C8-Based Products and Ongoing Industrial Transition.
Here a new global emission inventory of C4-C10perfluoroalkanesulfonic acids (PFSAs) from the life cycle of perfluorooctanesulfonyl fluoride (POSF)-based products in 1958-2030 is presented. In particular, we substantially improve and expand the previous frameworks by incorporating missing pieces (e.g., emissions to soil through land treatment, overlooked precursors) and updating parameters (e.g., emission factors, degradation half-lives). In 1958-2015, total direct and indirect emissions of perfluorooctanesulfonic acid (PFOS) are estimated as 1228-4930 tonnes, and emissions of PFOS precursors are estimated as 1230-8738 tonnes and approximately 670 tonnes for x-perfluorooctanesulfonamides/sulfonamido ethanols (xFOSA/Es) and POSF, respectively. Most of these emissions occurred between 1958 and 2002, followed by a substantial decrease. This confirms the positive effect of the ongoing transition to phase out POSF-based products, although this transition may still require substantial time and cause substantial additional releases of PFOS (8-153 tonnes) and xFOSA/Es (4-698 tonnes) in 2016 to 2030. The modeled environmental concentrations obtained by coupling the emission inventory and a global multimedia mass-balance model generally agree well with reported field measurements, suggesting that the inventory captures the actual emissions of PFOS and xFOSA/Es for the time being despite remaining uncertainties. Our analysis of the key uncertainties and open questions of and beyond the inventory shows that, among others, degradation of side-chain fluorinated polymers in the environment and landfills can be a long-term, (potentially) substantial source of PFOS.
Institute for Chemical and Bioengineering, ETH Zurich , Vladimir-Prelog-Weg 1, 8093 Zürich, Switzerland.
Zhanyun
0000-0001-9914-7659
Z
Wang
Institute for Chemical and Bioengineering, ETH Zurich , Vladimir-Prelog-Weg 1, 8093 Zürich, Switzerland.
Justin M
0000-0003-0517-7043
JM
Boucher
Institute for Chemical and Bioengineering, ETH Zurich , Vladimir-Prelog-Weg 1, 8093 Zürich, Switzerland.|RECETOX, Masaryk University , Kamenice 753/5, 62500 Brno, Czech Republic.
Martin
0000-0002-0809-7826
M
Scheringer
Department of Environmental Science and Analytical Chemistry (ACES), Stockholm University , 10691 Stockholm, Sweden.
Ian T
0000-0002-7035-8660
IT
Cousins
Institute for Chemical and Bioengineering, ETH Zurich , Vladimir-Prelog-Weg 1, 8093 Zürich, Switzerland.
Konrad
K
Hungerbühler
D004777:Environment; D004784:Environmental Monitoring; D005466:Fluorocarbons; D008962:Models, Theoretical; D012987:Soil
D005466:Fluorocarbons; D012987:Soil