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Article Title
Date

“Meta-analysis” of Temporal Trends of Legacy Persistent Organic Pollutants in Arctic Wildlife

2012-03-27

Map of the world from an Arctic orientation | © 78430491 / Photos.comA statistically robust analysis of 316 time-series of “legacy” persistent organic pollutants (POPs) in Arctic biota at various levels revealed mostly decreasing trends and only a few significantly increasing trends. In general, most time-series show significantly decreasing trends. Decreasing trends of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs), lindane (α-HCH, γ-HCH), and hexachlorobenzene (HCB) are found across the Arctic area covered by the available time-series, and in all groups of animals studied.

The analysis of biota from marine, freshwater and terrestrial ecosystems was undertaken with the purpose of generating a “meta-analysis” of temporal trend data collected over 20 to 30 years, for locations from Alaska in the west to northern Scandinavian in the east. In general, the statistical power of the POPs time-series to detect an annual change of the magnitude typically observed is rather low, and longer data time-series are therefore needed. In the meantime, further attempts could be made to reduce unexplained between-year variation, for instance, by standardizing sample collections and/or by adjusting contaminant concentrations for confounding factors.

The researchers also drew comparisons with trends in Arctic air. The trends observed in the biota were consistent with decreasing trends of legacy POPs reported for Arctic air, which appear to follow historic decreases in emissions. However, recent decreases in air are also starting to show signs of levelling off, perhaps an indication that atmospheric concentrations and, consequently those in the biota, are being less driven by primary sources and more by environmental processes and degradation.

Source:

Frank Rigét, Anders Bignert, Birgit Braune, Jason Stow, Simon Wilson. 2010. Temporal trends of legacy POPs in Arctic biota, an update. Science of the Total Environment 408:2874-2884 DOI: 10.1016/j.scitotenv.2009.07.036

Further reading:

Contact: Birgit Braune, 613-998-6694, Ecotoxicology and Wildlife Health Division