Tracking Toxaphene in the North American Great Lakes Basin. 2. A Strong Episodic Long-Range Transport Event

2005 ◽  
Vol 39 (21) ◽  
pp. 8132-8141 ◽  
Author(s):  
Jianmin Ma ◽  
Srinivasan Venkatesh ◽  
Yi-fan Li ◽  
Zuohao Cao ◽  
Sreerama Daggupaty
Keyword(s):  
Great Lakes ◽  
Long Range ◽  
North American ◽  
Long Range Transport ◽  
Great Lakes Basin ◽  
The North ◽  
Range Transport ◽  
North American Great Lakes

Tracking Toxaphene in the North American Great Lakes Basin. 1. Impact of Toxaphene Residues in United States Soils

2005 ◽  
Vol 39 (21) ◽  
pp. 8123-8131 ◽  
Author(s):  
Jianmin Ma ◽  
Srinivasan Venkatesh ◽  
Yi-Fan Li ◽  
Sreerama Daggupaty
Keyword(s):  
United States ◽  
Great Lakes ◽  
North American ◽  
Great Lakes Basin ◽  
The North ◽  
North American Great Lakes

scholarly journals Transport and fate of hexachlorocyclohexanes in the oceanic air and surface seawater

2011 ◽  
Vol 8 (3) ◽  
pp. 5537-5562 ◽  
Author(s):  
Z. Xie ◽  
B. P. Koch ◽  
A. Möller ◽  
R. Sturm ◽  
R. Ebinghaus
Keyword(s):  
Southern Ocean ◽  
Long Range ◽  
Water Exchange ◽  
Exchange Process ◽  
Lower Atmosphere ◽  
Long Range Transport ◽  
Surface Seawater ◽  
The North ◽  
Range Transport ◽  
Long Term Trends

Abstract. Hexachlorocyclohexanes (HCHs) are ubiquitous organic pollutants derived from pesticide application. They are subject to long-range transport, persistent in the environment, and capable of accumulation in biota. Shipboard measurements of HCH isomers (α-, γ- and β-HCH) in surface seawater and boundary layer atmospheric samples were conducted in the Atlantic and the Southern Ocean in October to December of 2008. ΣHCHs concentrations (the sum of α-, γ- and β-HCH) in the lower atmosphere ranged from 11.8 to 36.9 pg m−3 (mean: 26.6 ± 11.0 pg m−3) in the Northern Hemisphere (NH), and from 1.5 to 4.0 pg m−3 (mean: 2.8 ± 1.1 pg m−3) in the Southern Hemisphere (SH), respectively. Water concentrations were: α-HCH 0.33–46.8 pg l−1, γ-HCH 0.02–33.2 pg l−1 and β-HCH 0.11–2 pg l−1. HCH concentrations decreased from the North Atlantic to the Southern Ocean, indicating historical use of HCHs in the NH. Spatial distribution showed increasing concentrations from the equator towards North and South latitudes illustrating the concept of cold condensation and less interhemispheric mixing process. In comparison to concentrations measured in 1987–1999/2000, gaseous HCHs were slightly lower, while dissolved HCHs decreased by factor of 2–3 orders of magnitude. Air-water exchange gradients suggested net deposition for α-HCH (mean: 3759 pg m−2 day−1) and γ-HCH (mean: 1987 pg m−2 day−1), whereas β-HCH varied between equilibrium (volatilization: <0–12 pg m−2 day−1) and net deposition (range: 6–687 pg m−2 day−1), indicating a multi-hopper transport behavior. Climate change may significantly accelerate the releasing process of "old" HCHs from continental storage (e.g. soil, vegetation and high mountains) and drive long-range transport from sources to deposition in the open oceans. Biological productivities may interfere with the air-water exchange process as well. Consequently, further investigation is necessary to elucidate the long term trends and the biogeochemical turnover of HCHs in the oceanic environment.

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