Comparative Assessment of the Global Fate of alpha- and beta-Hexachlorocyclohexane before and after Phase-Out
2012 (English)In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 4, 2047-2054 p.Article in journal (Refereed) Published
Technical hexachlorocyclohexane (HCH) was one of the most widely used pesticides during the 20th century. Although production and use were phased-out during the 1990s, two of its major components, alpha- and beta-HCH, are still ubiquitous in the environment. Here, we have collected and analyzed data on concentrations of alpha- and beta-HCH in the atmosphere and oceans, including spatial and temporal trends and seasonalities. We apply a global fate and transport model to both isomers over the period 1950 to 2050 to rationalize current levels and trends at remote locations with estimated emissions and to forecast into the near future. Our model results indicate that secondary emissions from soils and oceans are currently controlling the observed rates of decline in the atmosphere. beta-HCH is declining more slowly than alpha-HCH due to its higher persistence, and we hypothesize that it will eventually become the predominant isomer of HCH in the environment. The model reproduces over 70% of measured concentrations of alpha-HCH in air and ocean water within factors of 3 and 5, respectively, and over 70% of measured concentrations of beta-HCH within factors of 8 and 20, respectively. The model results are only weakly sensitive to climate change-induced trends in Arctic sea-ice cover and temperature.
Place, publisher, year, edition, pages
2012. Vol. 46, no 4, 2047-2054 p.
Environmental Sciences Ecology
IdentifiersURN: urn:nbn:se:su:diva-76993DOI: 10.1021/es203109qISI: 000300465900013OAI: oai:DiVA.org:su-76993DiVA: diva2:529093