Low levels of munition compounds in commercially-available seafood from the North Sea and Baltic Sea pose limited risk to human seafood consumers

Relic munitions from World Wars I and II contaminate coastal waters worldwide. Toxic chemicals such as 2,4,6-trinitrotoluene (TNT) from underwater munitions (munition compounds, MCs) pose a risk to marine ecosystems and potentially human seafood consumers. Uptake of MCs by aquatic organisms and subsequent toxic effects have been shown in laboratory experiments and in field-collected samples of demersal fish and mussels, but the risk to human seafood consumers is not yet clear. Here, we report MC analyses of commercially-available fish from the North and Baltic Seas. Mercury (Hg) was also measured to compare the consumer risk from MCs to that of a common and better characterized marine contaminant that also has a potential source from underwater munitions. TNT and its metabolite compounds, amino-dinitrotoluene (ADNT) and diamino-nitrotoluene (DANT), were the most frequently detected MCs, but MCs were present only at very low levels in the tested seafood samples (0.07 ± 0.02 ng g^-1, 1.93 ± 3.2 ng g^-1, 5.57 ± 5.45 ng g^-1, 0.02 ± 0.01 ng g^-1, and 0.46 ± 0.34 ng g^-1-wet weight for TNT, ADNT, DANT, dinitrobenzene (DNB), and hexahydro-1,3,5-trinitro-1,3,5-triazinane (RDX), respectively; average ± S.D.). In comparison, Hg content in fish was variable (210 ± 219 ng g^-1-dry weight) and generally increased with trophic level. The results indicate that MC content in commercially available seafood poses negligible risk to human consumers when compared to oral reference doses, and Hg levels were higher but below the tolerable weekly intake established by the European Food Safety Authority for most seafood consumers.