Chronic toxicity studies INDEX

Proliferation Indexes from Repeat-Dose Chronic Toxicity Studies... 

Workers in the metals treatment industry are exposed to fumes, dusts, and mists containing metals and metal compounds, as well as to various chemicals from sources such as grinding wheels and lubricants. Exposure can be by inhalation, ingestion, or skin contact. Historically, metal toxicology was concerned with overt effects such as abdominal coHc from lead toxicity. Because of the occupational health and safety standards of the 1990s such effects are rare. Subtie, chronic, or long-term effects of metals treatment exposure are under study. An index to safety precautions for various metal treatment processes is available (6). As additional information is gained, standards are adjusted. 

There is today a tendency to consider the numerical values of the ADI as an overall maximum safe index for chronic ingestion toxicity. While this attitude might be justified in certain cases (ADIs for pesticide residues and certain individual food additives, or classes of food additives), it should be borne in mind that in most cases the niXmerical values of the ADI are derived from dose-effect curves and not from dose-response curves. In order to circumvent this difficulty the JECFA and JMPR have consistently recommended that the application of an ADI always be accompanied by studies on estimations of potential daily intakes of food additives and pesticide residues in food. 

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