Global contamination by persistent organochlorines and their ecotoxicological impact on marine mammals

https://tintuc.vnu.edu.vn/upload/scopus/0867.pdf

Asia-Pacific mussel watch: monitoring contamination of persistent organochlorine compounds in coastal waters of Asian countries

Contamination and toxic effects of persistent endocrine disrupters in marine mammals and birds

Butyltins in muscle and liver of fish collected from certain Asian and Oceanian countries.

Exposure assessment for trace elements from consumption of marine fish in Southeast Asia

Butyltin compounds (BTs) including mono-, di-, and tributyltin and total tin (sigmaSn), were determined in green mussels (Perna viridis) from various Asian developing countries, such as Cambodia, China (Hong Kong and southern China), Malaysia, India, Indonesia, the Philippines, and Vietnam, to elucidate the contamination status, distribution, and possible sources and to assess the risks on aquatic organisms and humans. Butyltin compounds were detected in green mussels collected from all the sampling location investigated, suggesting widespread contamination of BTs along the coastal waters of Asian developing countries. Among butyltin derivatives, tributyltin (TBT) was the predominant compound, indicating its ongoing usage and recent exposures in Asian coastal waters. Higher concentrations of BTs were found in mussels collected at locations with intensive maritime activities, implying that the usage of TBT as a biocide in antifouling paints was a major source of BTs. In addition, relatively high concentrations of BTs were observed in mussels from aquaculture areas in Hong Kong and Malaysia, as it has been reported in Thailand. With the recent improvement in economic status in Asia, it is probable that an increase in TBT usage will occur in aquaculture. Although contamination levels were generally low in mussel samples from most of the Asian developing countries, some of those from polluted areas in Hong Kong, India, Malaysia, the Philippines, and Thailand revealed levels comparable to those in developed nations. Furthermore, the concentrations of TBT in some mussels from polluted areas exceeded the threshold for toxic effects on organisms and estimated tolerable average residue levels as seafoods for human consumption. A significant correlation was observed between the concentrations of sigmaBTs and sigmaSn in mussels, and sigmaBTs were made up mostly 100% of sigmaSn in mussels taken from locations having intensive maritime/human activities. This suggests that anthropogenic BTs represent the major source of tin accumulation in mussels. To our knowledge, this is a first comprehensive report on butyltin pollution monitoring in developing countries in the Asia-Pacific region.

Asia-pacific mussel watch: Monitoring of butyltin contamination in coastal waters of asian developing countries

Concentrations of polychlorobiphenyls (PCBs), hexachlorocyclohexane isomers (HCHs), DDT compounds (DDTs), hexachlorobenzene (HCB), aldrin, dieldrin, heptachlor and heptachlor epoxide were determined in foodstuffs collected from different locations in Vietnam. Elevated levels of PCBs, DDTs, HCHs, and aldrin and dieldrin were found in animal fat, butter, meat, and seafood. Caviar and butter samples imported from the Soviet Union contained considerably higher amounts of PCBs, HCHs and DDTs. The average daily intake of some organochlorines by Vietnamese people were higher than those observed in most of the developed nations. The dietary intake of DDTs was the highest among various chemicals studied. Interestingly, the daily dietary intake of PCBs was comparable to those in developed countries. Fish, shellfish, prawn, and crab were the primary route of DDTs to humans, whereas cereals and vegetables were the predominant sources of PCBs and HCHs.

Residue pattern and dietary intake of persistent organochlorine compounds in foodstuffs from Vietnam.

Concentrations of persistent organochlorines (OCs), such as polychlorinated biphenyls (PCBs), 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB), and chlordane compounds (CHLs), were determined in whole-body homogenates of resident and migratory birds collected from the Red River estuary, North Vietnam, during March and October 1997. Contamination pattern was in the order of DDTs > PCBs > HCHs > CHLs > HCB in both resident and migratory birds. Residue concentrations, according to the feeding habit, showed little variability, which may reflect relatively similar trophic levels of the bird species analyzed. Resident birds accumulated greater concentrations of DDTs as compared to migrants. In contrast, HCH residues were greater in migratory species. Higher proportions of p,p'-DDT to total DDT concentrations were found in many species of residents and migrants, indicating recent exposure to technical DDT in northern Vietnam. Congener-specific PCB analysis showed the predominance of penta- and hexachlorobiphenyls in all the species analyzed. Estimation of hepatic microsomal enzyme activities suggested higher metabolic capacity for PCB congeners in shore birds from Vietnam as compared to higher-trophic predator birds and marine mammals. Comparison of OC residues in avian species in Asia-Pacific revealed that DDT residues in resident birds in North Vietnam are among the highest values reported for the countries surveyed, suggesting recent usage of DDT in Vietnam. Available data for birds, fish, and bivalves from the recent Asia-Pacific Mussel Watch Program suggested that Vietnam might be a potential source of DDT contamination in Asian developing countries. To our knowledge, this is the first study of the OC accumulation in avian species from Vietnam.

/pdf/persistent-organochlorine-residues-and-their-bioaccumulation-6nnxr61dic.pdf

Nguyen Duc Hue

Papers

Asia-pacific mussel watch: Monitoring of butyltin contamination in coastal waters of asian developing countries

Residue pattern and dietary intake of persistent organochlorine compounds in foodstuffs from Vietnam.

Persistent organochlorine residues and their bioaccumulation profiles in resident and migratory birds from North Vietnam