Hideo Hidaka

PCBs and chlorinated hydrocarbon pesticides in Antarctic atmosphere and hydrosphere

Abstract PCBs and chlorinated hydrocarbon pesticides such as DDTs and HCHs (BHCs) were measured in air, water, ice and snow samples collected around the Japanese research stations in Antarctica and adjacent oceans during December 1980 to March 1982. The atmospheric concentrations of chlorinated hydrocarbons decreased in the transport process from northern lands to Antarctica, but the compositions of PCBs, DDT compounds and HCH isomers were relatively uniform throughout this process. Regional and seasonal variations were found in aerial concentrations of these pollutants at Syowa Station and adjacent seas in Antarctica. Chlorinated hydrocarbons were also detected in snow, ice, lake water and sea water samples, in which rather high concentrations were found in snow and ice samples. This suggests that snow and ice serve as media of supply of these pollutants into Antarctic marine environment. Most interestingly, the concentrations of DDTs and higher chlorinated biphenyls were much lower in sea water under fast ice than in that from outer margin of pack ice. This indicates that the active removal of these pollutants is occurred in the sea under fast ice, and that is strongly associated with high primary productivity. It is, therefore, presumed that the concentrations of PCBs and DDTs in marine organisms living under fast ice in Antarctica could be lower than those in other oceans.

Bioconcentration and residue patterns of chlordane compounds in marine animals: invertebrates, fish, mammals, and seabirds.

The bioconcentration and compositional patterns of chlordane compounds (CHLs: cis-chlordane, transchlordane, cis-nonachlor, trans-nonachlor, and oxychlordane) were investigated in organisms from two marine ecosystems. The bioconcentration factors (BCF: concentration in organism/concentration in seawater) of CHLs in lower trophic organisms were in between the values obtained for HCHs (a-HCH, P-HCH, and yHCH) and DDTs (p,p’-DDE and p,p’-DDT). In the case of higher trophic organisms, the scatter in the biomagnification factors (BMF: concentration in organism/concentration in food) of CHLs was found to be wider than those observed for HCHs and DDTs. Also, there were remarkable differences in CHLs composition among higher trophic organisms. For example, the percent composition of oxychlordane, which is one of the persistent metabolites of CHLs in seabirds from both areas, was higher than those of marine mammals.

Global distribution and atmospheric transport of chlorinated hydrocarbons: HCH (BHC) isomers and DDT compounds in the Western Pacific, Eastern Indian and Antarctic Oceans

Concentrations of chlorinated hydrocarbons such as HCH isomers and DDT compounds were determined in air and surface water samples taken from the Western Pacific, Eastern Indian and Antarctic Oceans. The most interesting finding was their presence in measurable concentrations in the Antarctic Ocean. Chlorinated hydrocarbon pesticides are widely distributed in the open ocean environment over both the northern and southern hemispheres, and some characteristic distribution patterns of pesticide species in different oceanic regions were observed both in air and water samples. HCH residues found in the northern hemisphere were much higher in concentration than those in the southern hemisphere. On the other hand, higher concentrations of DDT residues were found in the tropical regions, but their levels were not so different between both the northern and southern hemispheres. HCH isomers found in the northern hemisphere had the following order of concentrations:α-HCH>γ HCH>β-HCH, while in the southern hemisphereγ-HCH was apparently dominant. DDT compound compositions were rather uniform in all the oceans surveyed, and more than 50% wasp,p′-DDT. These facts can be explained by the world wide situation regarding pesticide use and the physicochemical properties of the pesticides such as their vapor pressures and water solubilities. In addition, the meridional circulation of the atmosphere, particularly the mass flows of the Hadley and Ferrel cells in the troposphere, also contributes to the atmospheric transport and global distribution of these pesticides.

Tissue distribution of heavy metals in Weddell seals (Leptonychotes weddellii)

Abstract Tissue distributions of heavy metals were investigated in the Weddell seal collected around Syowa Station, Antarctica. Generally, the metal concentrations were high in liver and kidney and low in brain, blubber and skin. Fe in blood and spleen, Zn in bone, and Mn and Cd in pancreas and gastrointestinal organs were also relatively high. Wide variations of the metal concentrations in different bones were also observed. The concentrations of Fe and Cd were positively correlated with moisture content of the bones, while those of Mn and Zn increased with increase of Ca content in the bone. Majority of the metal burden in the body existed in muscle and liver. A relatively high burden of Cd was in the kidney. Based upon these results, the suitability of the tissues of a seal for ecological and toxicological comparisons is discussed.

Bioaccumulation of organochlorines (PCBs and p,p'-DDE) in Antarctic Adelie penguins Pygoscelis adeliae collected during a breeding season

Abstract Subcutaneous fat (SCF) and abdominal fat (AF) of ten Adelie penguins (five male and five female) and the muscle, liver, bone and brain samples from three male specimens, collected during different days of starvation in a breeding season, were analysed for concentrations of PCBs and p,p ′-DDE. All the specimens analysed contained detectable levels of PCBs and DDE and both compounds were found to be highly concentrated in the fat-rich tissues, to the extent that the SCF burdens of both compounds can be considered as the total body burdens. On starvation during breeding, the concentrations of both compounds increased simultaneously in the declining fat reserves, as well as in other organs. Some redistribution of organochlorines to other tissues from the fat reserves was also noticed during starvation. The bioconcentration factor for DDE was found to be higher than for PCBs in all the levels of the Antarctic food chain and also the DDE/PCB ratio increased with increase in trophic levels, both indicating the high residual potentiality of DDT compounds in higher animals.

DDTs and PCB isomers and congeners in antarctic fish.

Polychlorinated biphenyls (PCBs) and DDTs (p,p′-DDE +p,p′-DDT) were quantitated in four species of antarctic fish collected around the Japanese Antarctic Research Station during January to December 1981. PCBs ranged between 0.08 and 0.77 ng/g and DDTs from 0.3 to 1.9 ng/g, wet weight basis in whole body homogenates. InPagothenia borchgrevinki, the largest sample (N=21), both classes of chlorinated hydrocarbons increased linearly with body weight. Analysis of PCB isomers and congeners by mass fragmentography showed greater retention of the more highly chlorinated biphenyls in larger specimens. The bottom dwellingTrematomus bernacchii andT. hansoni revealed greater concentrations of highly chlorinated biphenyls than the surface dwellingP. borchgrevinki. In general, the concentrations of PCBs and DDTs in antarctic fish were very low compared to other open ocean water fish reported in the literature; this agreed with atmospheric and hydrospheric concentrations of PCBs and DDTs in antarctic regions where low levels were reported.

Chlordane compounds residues in Weddell seals (Leptonychotesweddelli) from the Antarctic

Abstract Weddell seal samples taken from the Antarctic have been found to be contaminated with chlordane compounds. ΣChlordane ( cis -chlordane + cis -nonachlor + trans -nonachlor + oxychlordane ) was present in blubber of seals at the range of 12 - 62 ng/g fresh weight. The order of chlordane compound concentrations was trans -nonachlor > oxychlordane > cis -nonachlor > cis -chlordane . Relative aboundance of cis -chlordane in Σchlordane is higher than that in humans. A probable explanation for their occurrence in the Antarctic is an airborne transport.

Avoidance test of a fish, medaka (Oryzias latipes), to aquatic contaminants, with special reference to monochloramine

The avoidance behavior of fish is a sensitive indicator to aquatic contaminants such as surfactants, pesticides, and residual chlorine. This paper describes an avoidance test with special reference to monochloramine by medaka (killifish,Oryzias latipes) in a small modular chamber system with a symmetrical parallel-flow. The significant avoidance concentration (P = 0.05) was 5.7 μg/L as combined residual chlorine, which is the lowest among the residual chlorine avoidance concentrations reported in the literature. The avoidance curves of medaka to monochloramine exhibited a similar pattern to those of anionic surfactants.