Declining Dioxin concentrations in the Rhone River, France, attest to the effectiveness of emissions controls

Environmental Science & Technology
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By: , and 

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Abstract

Emission-control policies have been implemented in Europe and North America since the 1990s for polychlorodibenzodioxins (PCDDs) and furans (PCDFs). To assess the effect of these policies on temporal trends and spatial patterns for these compounds in a large European river system, sediment cores were collected in seven depositional areas along the Rhone River in France, dated, and analyzed for PCDDs and PCDFs. Results show concentrations increase in the downstream direction and have decreased temporally at all sites during the last two decades, with an average decrease of 83% from 1992 to 2010. The time for a 50% decrease in concentrations (t1/2) averaged 6.9 ± 2.6 and 9.1 ± 2.9 years for the sum of measured PCDDs and PCDFs, respectively. Congener patterns are similar among cores and indicate dominance of regional atmospheric deposition and possibly weathered local sources. Local sources are clearly indicated at the most downstream site, where concentrations of the most toxic dioxin, TCDD, are about 2 orders of magnitude higher than at the other six sites. The relatively steep downward trends attest to the effects of the dioxin emissions reduction policy in Europe and suggest that risks posed to aquatic life in the Rhone River basin from dioxins and furans have been greatly reduced.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Declining Dioxin concentrations in the Rhone River, France, attest to the effectiveness of emissions controls
Series title Environmental Science & Technology
DOI 10.1021/acs.est.5b03416
Volume 49
Issue 21
Year Published 2015
Language English
Publisher ACS publications
Contributing office(s) National Water Quality Assessment Program
Description 8 p.
First page 12723
Last page 12730
Country France
Online Only (Y/N) N
Additional Online Files (Y/N) N