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Strontium-90 (90Sr) was released together with radioactive cesium (Cs) from the Fukushima Dai-ichi Nuclear Power Plant (FNPP) accident. Although the total amount of 90Sr released into the marine environment from the FNPP was estimated to be a factor of 100 lower than that of 137Cs, the public have been concerned about the safety of commercial species because of the tendency of accumulation in bones of organisms, its long physical half-life and less information about 90Sr concentrations in commercial species. In this study, we investigated the concentrations of 90Sr in marine fishes off Japan before and after the FNPP accident. Except for within a 20-km radius from the FNPP, 90Sr concentrations higher than the background level (

Tributyltin-binding protein type 1 (TBT-bp1) is a member of the lipocalin family of proteins which bind to small hydrophobic molecules. In this study, we expressed a recombinant TBT-bp1 (rTBT-bp1, ca. 35kDa) in a baculovirus expression system and purified the protein from the hemolymph of silkworm larvae injected with recombinant baculovirus. After incubation of a mixture of rTBT-bp1 and TBT and its fractionation by means of gel filtration chromatography, TBT was detected in the elution peak of rTBT-bp1, confirming the binding potential of rTBT-bp1 for TBT. An assay of the ability of rTBT-bp1 or native TBT-bp1 (nTBT-bp1) to restore osteoblastic activity inhibited by TBT showed that co-treatment of the scales with rTBT-bp1 or nTBT-bp1 in combination with TBT restored osteoblastic activity in goldfish scales, whereas treatment with TBT alone significantly inhibited osteoblastic activity. These results suggest that TBT-bp1 as a lipocalin member might function to decrease the toxicity of TBT by binding to TBT.

Contaminations in sediments by polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs were investigated at 44 sites in Osaka Bay, Japan. Concentrations of total PAHs and alkylated PAHs were in the range 6.40-7800 ng/g dry weights and 13.7-1700 ng/g dry weights, respectively. The PAH concentrations tended to be higher along the shoreline in the vicinities of big ports, industrialized areas, and densely populated regions such as the cities of Osaka and Kobe. The major sources appeared to be pyrogenic or both pyrogenic and petrogenic at most of the sites. PAH concentrations were remarkably high at a site near Kobe, where the concentrations of dibenzo(a,h)anthracene and benzo(g,h,i)perylene exceeded the effects-range-medium concentration and eight PAHs were above the corresponding effects-range-low concentrations. Those PAHs may have been derived from the great fire associated with the large earthquake in 1995.

We investigated levels of the pollutant tributyltin (TBT) in blood of pufferfishes (six species), Japanese sea perch, red sea bream, Japanese common goby, Japanese flounder, rockfish, conger eel, and sea mullet collected off the coast of northern Kyushu, Japan. We found considerable levels of TBT (1.4–190 ng/mL) accumulated in the blood of these fish. Blood TBT concentrations were 1.3–22.5 times liver concentrations and 4.9–78 times muscle concentrations, except in conger eel and mullet. We detected TBT (16–111 ng/mL-blood) in the plasma of the fine-patterned puffer (Takifugu poecilonotus) year-round, without any apparent seasonal trend. These results suggest that fish inhabiting coastal areas of Kyushu, Japan, continue to be contaminated with TBT.