Distribution of persistent organochlorines in the oceanic air and surface seawater and the role of ocean on their global transport and fate

Organochlorine Pesticides in the Atmosphere and Surface Water from the Equatorial Indian Ocean: Enantiomeric Signatures, Sources, and Fate

“…Considering the samples with exceptional high concentrations (Stations 15 and 16 for DDTs and Station 14 for chlordanes) as outliers in this study, the average concentrations of α-HCH and γ-HCH at other sites were substantially lower than the data reported in the Bay of Bengal and Arabian Sea in 1989, 4 TC and CC showed similar concentration levels, while p,p′-DDT was 77 times higher (Table S3), indicating there were still fresh input of DDTs and chlordanes to the water phase as discussed above. The significant decrease of α-HCH concentration in the equatorial Indian Ocean seawater from 100−1200 pg L −1 in1989 4 to 0.21−1.7 pg L −1 in 2011 should be related to the diffusion by the North Equatorial Current and volatilization into the atmosphere and consequent transport to the higher latitude.…”

“…4 To date, many studies have been carried out on the air−water exchange and biogeochemical processes of OCPs in oceans and seas. Those studies focused on the Arctic region and subarctic area, such as the eastern Arctic Ocean, 7,8 the North American Arctic Ocean, 9,10 and the North Atlantic Ocean.…”

Current status of persistent organic pesticides residues in air, water, and soil, and their possible effect on neighboring countries: A comprehensive review of India

“…Further, some researchers have opined that the Indian monsoon system plays an important role in the transportation of persistent organic pesticides across major Indian cities. Iwata et al (1993) reported that tropical Asia, including India, is a significant emission source of global persistent organic pesticide contamination. Rajendran et al (1999) found low level of OCPs in air samples collected from the coastal regions of southern India.…”

Organochlorine pesticides in seawater and the surrounding atmosphere of the marginal seas of China: Spatial distribution, sources and air–water exchange

“…Oceans are believed to be the largest sink of POPs (Dachs et al, 2002;Iwata et al, 1993), which may be converted into a secondary source of particular POPs, such as dichlorodiphenyltrichloroethane (DDT) (Stemmler and Lammel, 2009) and alpha-Hexachlorocyclohexane (HCH) (Li and Bidleman, 2003), long after these compounds were banned. In addition, oceans act as remote monitoring sites of regional/global distribution and temporal trend of POPs, as the outflow of these pollutants from adjacent land sources, carried by monsoon/air masses, can travel long distances.…”

“…Anthropogenic pollutants in the marginal seas, inputted from atmospheric deposition and fluviatile transport, could be quickly dissipated by the surface current. Available data for OCP concentrations in the atmosphere and surface seawater over the marginal seas of China are sparse (Ding et al, , 2009Iwata et al, 1993;Wu et al, 2010;.…”