DNA OXIDATIVE DAMAGE AND VITAMIN-A REDUCTION IN FISH FROM A LARGE LAKE SYSTEM IN LABRADOR, NEWFOUNDLAND, CONTAMINATED WITH IRON-ORE MINE TAILINGS

Reactive ox),gen species are believed to play an important role in a v ariety of pathological conditions and considerable speculation has ari sen on whether contaminants might play, a role in human and animal hea lth through enhancement of various oxidative processes. Although epide miological information is limited with respect to observations on eith er humans or wildlife, evidence has been produced for pollutant-mediat ed DNA oxidative damage in fish in Puget Sound. We now provide evidenc e for a level of DNA oxidative damage in trout from a large lake syste m in Labrador, Newfoundland, receiving effluents from iron-ore mines. Studies were carried out by CC-MS with selected ion monitoring and hig her levels of the ring opening products, Fapyguanine and Fapyadenine, were detected in the DNA of liver tissues of fish from the lake receiv ing the highest load of iron-ore tailings. Notably, fish in this lake also had markedly reduced levels of vitamin A. The study provides a se cond case history for oxidative damage in fish in the environment and indicates the potential importance of transition heavy metals such as iron in producing damage. It also lend; support to the evolving viewpo int that many water quality guidelines should be revisited in terms of new ecotoxicological criteria. (C) 1998 Elsevier Science Ltd. All rig hts reserved.