Geoscience

Current Pollutants POPs Sources in Ocean

With the implementation of the Stockholm Convention, the primary contamination of persistent organic pollutants (POPs) has been effectively controlled on the global scale but the pollution caused by secondary emission and long-range transport has become prominent recently. As the largest sink of POPs, the importance of ocean is increasing and so does its observation. Dr Zhang Gan’s research group in Guangzhou Institute of Geochemistry, CAS, has conducted an atmospheric and water survey campaign along the cruise from April to May, 2011 on the Chinese research vessel Shiyan I to investigate the latest OCP pollution status over the equatorial Indian Ocean. By analyzing the fugacity ratios and chiral enantiomers of 14 organochlorine pesticides (OCPs), potential sources of POPs in the region were evaluated. After prohibition of OCPs, the overall content of those compounds have decreased, but relatively high values still occurred close to the continents. Over the clean open waters of the Indian Ocean, just a small part of OCPs in the atmosphere is from seawater evaporation. It indicates that the oceans were still dominated by the surrounding continental sources and the long-range transport from secondary emissions, even though primary pollution has been controlled. The results of recent research have been published in the International Journal of Environmental Science & Technology. (Huang, Y., Xu, Y., Li, J., Xu, W., Zhang, G., Cheng, Z., Liu, J., Wang, Y., Tian, C., Organochlorine pesticides in the atmosphere and surface water from the equatorial Indian ocean:. enantiomeric signatures, sources, and fate Environmental science & technology 2013, 47, 13395-403).