Uptake, Excretion and Toxicity of Volatile Aromatics in Aquatic Organisms

Uptake, Excretion and Toxicity of Volatile Aromatics in Aquatic Organisms ) 

Several studies have been made on the uptake of aromatic compounds by fish following exposure over several weeks, the tissues of rainbow trout contain naphthalene in concentrations of 40-300 times and in the gall of 13,000-23,500 times that of the water [213]. Salmonoids take up aromatics - anthracene more than naphthalene, and naphthalene more than benzene - via the gills or through the skin, and these pollutants are deposited primarily in the gall bladder, the liver and the brain, where they are metabolized [47]. Concentrations of as little as 0.5 ppm naphthalenes in seawater lead to pronounced accumulations in the flesh within a 

When Cirolana borealis is exposed to 1 ppm toluene, practically no effects are noted [214]. At 5.7 ppm, the swimming activity increases at first and the contents of the stomach are expelled through the mouth [214]. After 400 h, the fishes are totally inactive and lie on their backs or sides [214]. Various methods to determine the behaviour of Cirolana borealis under conditions of stress when exposed to toluene have been compared [214]. 

The decomposition of benzene and naphthalene and its homologues by microorganisms has already been discussed earlier. The metabolizing mechanisms of naphthalenes in fish have been well studied [47, 49]. Decomposition products of chlorobenzene in daphnia, mosquitos, snails and fishes are the polar compounds chlorophenol and chloro-o-dihydroxybenzene amongst other compounds, those of nitrobenzene aniline, acetanilide, aminophenols and nitrophenols and those of hexachlorobenzene pentachlorophenol and unknown compounds [71]. Bromoben-zene is deactivated to the toxic bromophenol [217]. In the case of man and land mammals, studies have concentrated on the metabolism of benzene, toluene, xylenes and styrene, which are also significant in occupational medicine [12, 13, 136, 195, 196, 215-217], A comparison of the metabolism of benzene into phenol in various animal species with the aid of microsomal preparations of the lungs or liver yielded vast differences. However, it is possible for benzene, in part, to inhibit or prevent its own metabolism [218]. 

---