Pesticides in Western Canadian Mountain Air and Soil
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- 作者：Gillian L. Daly ; Ying D. Lei ; Camilla Teixeira ; Derek C. G. Muir ; Frank Wania
- 刊名：Environmental Science & Technology
- 出版年：2007
- 出版时间：September 1, 2007
- 年：2007
- 卷：41
- 期：17
- 页码：6020 - 6025
- 全文大小：717K
- 年卷期：v.41,no.17(September 1, 2007)
- ISSN：1520-5851
文摘
The distribution of organochlorine pesticides (OCP; in pastand current use) in the mountains of western Canadawas determined by sampling air, soil, and lichen along threeelevational transects in 2003-2004. Two transects westof the Continental Divide were located in Mount Revelstokeand Yoho National Park, while the Observation Peaktransect in Banff National Park is east of the divide. XAD-based passive air samplers, yielding annually averagedair concentrations, were deployed, and soils were collectedat all 22 sampling sites, whereas lichen were onlysampled in Revelstoke. Back trajectory analysis showedlimited air mass transport from the Prairies to the east, buta high frequency of air arriving from the southwest,which includes agricultural regions in British Columbiaand Washington State. Endosulfan, dieldrin, and 
-hexachlorocyclohexane were the most prevalent OCPs in air andsoil; hexachlorobenzene was only abundant in air;chlorothalonil, dacthal, and pentachloronitrobenzene werealso consistently present. OCP air concentrations weresimilar across the three transects, suggesting efficientatmospheric mixing on a local and regional scale. Soilconcentrations and soil/air concentration ratios of manyOCPs were significantly higher west of the Continental Divide.The soil and lichen concentrations of most OCPs increasedwith altitude in Revelstoke, and displayed maxima atintermediate elevations at Yoho and Observation Peak.These distribution patterns can be understood as beingdetermined by the balance between atmospheric depositionto, and retention within, the soils. Higher deposition, dueto more precipitation falling at lower temperatures, likelyoccurs west of the divide and at higher elevations. Higherretention, due to higher soil organic matter content, isbelieved to occur in soils below the tree line. Highestpesticide concentrations are thus found in temperate mountainsoils that are rich in organic matter and receive largeamounts of cold precipitation.
-hexachlorocyclohexane were the most prevalent OCPs in air andsoil; hexachlorobenzene was only abundant in air;chlorothalonil, dacthal, and pentachloronitrobenzene werealso consistently present. OCP air concentrations weresimilar across the three transects, suggesting efficientatmospheric mixing on a local and regional scale. Soilconcentrations and soil/air concentration ratios of manyOCPs were significantly higher west of the Continental Divide.The soil and lichen concentrations of most OCPs increasedwith altitude in Revelstoke, and displayed maxima atintermediate elevations at Yoho and Observation Peak.These distribution patterns can be understood as beingdetermined by the balance between atmospheric depositionto, and retention within, the soils. Higher deposition, dueto more precipitation falling at lower temperatures, likelyoccurs west of the divide and at higher elevations. Higherretention, due to higher soil organic matter content, isbelieved to occur in soils below the tree line. Highestpesticide concentrations are thus found in temperate mountainsoils that are rich in organic matter and receive largeamounts of cold precipitation.