Identification and accumulation of aromatic sensitizers in fish from paper recycling in Japan

Aromatic sensitizers and related compounds (SRCs) originating from thermal recording material as impurities in waste paper have been detected in aquatic environments near cities where the paper industry is flourishing. In the present study, the levels of exposure to such SRCs and the stable isotope ratios (δ13C and δ15N) in different fish species (Konosirus punctatus, Takifugu niphobles, and Tribolodon hakonensis) were analyzed. These fish species were collected from the vicinity of waste paper recycling plants in Japan. Eleven SRCs were identified in fish muscle at total concentration levels (ΣSRCs) of 64 to 818 ng/g wet weight (mean 181 ng/L wet wt). The dominant SRCs in the fish samples were 1,1-di(4-methylphenyl)ethane, 1,2-bis(3-methylphenoxy)ethane, and 1,4-dibenzyloxybenzene. Stable isotope ratios showed that, although three species feed on the same trophic level, K. punctatus and T. niphobles live in waters farther offshore than those in which T. hakonensis live. The contributions of various factors to the accumulation were also assessed. The lipid content (r2 = 0.512, p < 0.001) was found to be the significant factor that influenced accumulation of SRCs in fish. The results also revealed significant positive correlation between the accumulation patterns and SRC components in water (r2 = 0.512–0.658, all p values <0.05), but they showed negative correlations between the SRCs in fish and log KOW values. This suggests that the aqueous route is the predominant route for the accumulation of SRCs in fish. This is the first study on the accumulation of aromatic sensitizers in aquatic biota. Environ. Toxicol. Chem. 2012;31:1202–1208. © 2012 SETAC