Toxicities of Polycyclic Aromatic Hydrocarbons in Fish and Marine Invertebrates

The toxicity of polycyclic aromatic hydrocarbons (PAHs) in aquatic animals is discussed, with particular focus on fish. In aquatic animals, our research group has recently investigated the toxicity of monohydroxylated PAHs (OHPAHs) which are metabolites of PAHs. In in vivo experiments on aquatic animals such as fish and sea urchin, it has been reported that OHPAHs are produced as metabolites from parent PAHs. In fish and sea urchin, OHPAHs exert greater toxicity than PAHs. Furthermore, to analyze the toxicity of PAHs on bone metabolism, we developed an original in vitro bioassay with fish scales having osteoblasts (bone formation cells) and osteoclasts (bone resorption cells). The sensitivity of our bioassay is quite high. In the case of cadmium, its concentration (even at 1 × 10−13 M) influenced osteoclastic activity in fish scales. Using a newly developed bioassay, it was demonstrated that seawater polluted with highly concentrated PAHs inhibited osteoblastic activity even if polluted seawater was added into a culture medium at a 500-fold dilution. Therefore, the prevention of PAH pollution is particularly important, given the toxicity of PAHs to aquatic animals.