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Combined spatial and retrospective analysis of fluoroalkyl chemicals in fluvial sediments reveal changes in levels and patterns over the last 40 years.
- Source :
- Environmental Pollution; Oct2019, Vol. 253, p1117-1125, 9p
- Publication Year :
- 2019
-
Abstract
- Bed sediments and a dated sediment core were collected upstream and downstream from the city of Lyon (France) to assess the spatial and temporal trends of contamination by per- and polyfluoroalkyl substances (PFASs) in this section of the Rhône River. Upstream from Lyon, concentrations of total PFASs (ΣPFASs) in sediments are low (between 0.19 and 2.6 ng g<superscript>−1</superscript> dry weight - dw), being characterized by a high proportion of perfluorooctane sulfonate (PFOS). Downstream from Lyon, and also from a fluoropolymer manufacturing plant, ΣPFASs concentrations reach 48.7 ng g<superscript>−1</superscript> dw. A gradual decrease of concentrations is reported at the coring site further downstream (38 km). Based on a dated sediment core, the temporal evolution of PFASs is reconstructed from 1984 to 2013. Prior to 1987, ΣPFASs concentrations were low (≤2 ng g<superscript>−1</superscript> dw), increasing to a maximum of 51 ng g<superscript>−1</superscript> dw in the 1990s and then decreasing from 2002 to the present day (∼10 ng g<superscript>−1</superscript> dw). In terms of the PFAS pattern, the proportion of perfluoroalkyl sulfonic acids (PFSAs) has remained stable since the 1980s (∼10%), whereas large variations are reported for carboxylic acids (PFCAs). Long chain- (C > 8) PFCAs characterized by an even number of perfluorinated carbons represent about 74% of the total PFAS load until 2005. However, from 2005 to 2013, the relative contribution of long chain- (C > 8) PFCAs with an odd number of perfluorinated carbons reaches 80%. Such changes in the PFAS pattern likely highlight a major shift in the industrial production process. This spatial and retrospective study provides valuable insights into the long-term contamination patterns of PFAS chemicals in river basins impacted by both urban and industrial activities. Image 1 • Upstream-downstream PFAS concentration gradient in bed sediments in the Rhône River. • Reconstruction of temporal trends of PFAS contamination using a sediment core. • Evidence of global PFSA background levels. • Release of long-chain PFCAs from a point source into the river. • Change of PFCA pattern through time likely reflects changes in production processes. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 02697491
- Volume :
- 253
- Database :
- Supplemental Index
- Journal :
- Environmental Pollution
- Publication Type :
- Academic Journal
- Accession number :
- 138104651
- Full Text :
- https://doi.org/10.1016/j.envpol.2019.07.079