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Residues and sources of HCHs and DDTs in the sediments of land-based sewage outlet to the Zhanjiang Bay, China
Zhao Lirong, Shi Yuzhen, Zhao Hui, Zhang Jibiao, Sun Xingli
2019, 38(12): 8-13. doi: 10.1007/s13131-019-1432-4
Keywords: Zhanjiang Bay, sediment, DDTs, HCHs
Due to the large usage of DDT-containing antifouling paints and lindane in China, heavy residuals of DDTs and HCHs have been found in many fishing harbors, but there is lack of studies on this issue for the Zhanjiang Bay which is an important fishing harbor and mariculture zone in South China. To evaluate the pollution status and sources of HCHs and DDTs in the Zhanjiang Bay, the concentrations, spatial distributions and sources in the sediments of 11 land-based sewage outlets to the Zhanjiang Bay were investigated. Since the 1980s, HCHs residuals had obviously decreased in studied areas, but DDTs had little change, even abnormally high levels were found in some sites. The content percentages and diagnostic ratios of HCHs isomers and DDTs showed that the source of HCHs was derived from soils around the bay and recent input of lindane, and DDTs were from historical residues of technical DDTs and fresh input of DDT-containing antifouling paints on fishing ships. Based on sediment quality guidelines, DDTs would be of more concern for the ecotoxicological risk on marine environment and adverse effects on benthonic organisms. This study indicated that lindane and DDT-containing products may be still used in some places of Zhanjiang City. It should be urgent to control their usage and clean the DDTs-contaminated sites by the local government.
Heavy metals,polycyclic aromatic hydrocarbons and organochlorine pesticides in the surface sediments of mangrove swamps from coastal sites along the Leizhou Peninsula, South China
TANG Yijie, FANG Zhanqiang, YU Shixiao
2008(1): 42-53.
Keywords: sediment, mangrove swamps, heavy metals, PAHs, DDTs, HCHs
Contents of heavy metals, polycyclic aromatic hydrocarbons (PAHs), dichlorodiphenyltrichloroethanes (DDTs) and hexachlorcyclohexanes (HCHs) in surface sediments from mangrove areas of the Leizhou Peninsula were analyzed in July and November 2005. Risk assessment criteria applied by Long E R et al. (1995) and Long E D et al. (1998) (effects range low, ERL; effects range mean, ERM) of chemicals in sediments from the gulf or estuary were used to assess the potential ecological risks of heavy metals, PAHs, DDTs and HCHs to aquatic organisms in the studied area. The results indicated that the average contents of zinc, nickel, chromium, lead, copper, arsenic and mercury were (61.97±55.87), (59.99±39.01), (47.93±28.37), (26.64±13.00), (23.45±41.96), (9.32±3.62), (0.14±0.18) mg/kg in dry weight in the sediment samples collected from five studied sites in the Leizhou Peninsula, respectively. Cadmium was not calculated due to its content being below the detection limit (< 0.3 mg/kg). The average levels of Cr, Cu, Ni, Pb, Zn and Hg exceed their background values. The average contents of Ni were higher than ERM. The contents of PAHs in the sediments from the five studied sites were (79.78±43.70) ng/g in dry weight, far lower than ERL(4 022 ng/g). The contents of DDE, DDD and DDTs in the sediments from five studied sites were (2.60±4.68), (17.52±27.25), (27.78±46.64) ng/g in dry weight respectively, clearly higher than ERL, and the average contents of DDT were (7.66±15.93) ng/g in dry weight, much higher than ERM. HCHs could be detected in the sediments only from Gaoqiao sampling site, with the average contents (0.07±0.08) ng/g in dry weight.