[The liver and environmental poisons]

For almost a century now numerous examples of acute and subacute hepatic injury from exposure to toxic agents in the occupational or non-occupational environment have been extensively studied and are well documented, but such events are comparatively rare. In contrast, epidemiological data associating exposure to environmental chemicals with chronic liver disease or primary hepatic malignancies in the human is scarce as compared with the vast body of literature concerning chronic pulmonary disease as a consequence of exposure at the workplace. Large-scale industrial production of many newly synthesized organic chemicals began during the period 1930-1940 but it was not until the 1960s that the output increased exponentially. Consequently, the spectrum of environmental influences is gaining increasing complexity since simultaneous or sequential exposure to a variety of pollutants is becoming the rule rather than the exception. Possible interaction or synergism of environmental agents--even of those which in themselves or for their low dosage level may be considered "harmless" - and particularly latency periods of more than one decade further complicate preventive strategies. The liver, as the central site for the biotransformation of xenobiotics, deserves special attention when new chemicals which are to be introduced into the environment are being tested for their potential toxicity, especially since many hepatotoxic agents have been shown to undergo bioactivation in the liver. Currently available information on hepatic injury due to environmental agents is briefly reviewed and comprises solvents and degreasing agents, pesticides, polyhalogenated biphenyls, dioxins and dibenzofuranes, epoxy resin hardeners, vinyl chloride, naturally occurring hepatotoxins in plants and fungi, herbal medicines and traditional remedies and a side-light on the Reye syndrome and the Spanish "toxic oil syndrome".