Fume blanc

Blanc PD, Wong H, Bernstein MS, et al An experimental human model of metal fume fever. Ann Int Med 114 930-936, 1991... 

In a group of 14 welders acutely exposed to 77-153 mg zinc/m as zinc oxide, significant correlations between the concentration of airborne zinc and the proportion of activated T cells, T helper cells, T inducer cells, T suppressor cells, and activated killer T cells were observed 20 hours after exposure (Blanc et al. 1991). In addition, significant increases in levels of polymorphonuclear leukocytes, macrophages, and all types of lymphocytes were observed in the bronchoalveolar lavage fluid 20 hours after exposure. Increased levels of lymphocytes, with a predominance of CD8 cells, in the bronchoalveolar lavage fluid were reported in a case study of a smelter exposed to unspecified levels of zinc fumes (Ameille et al. 1992). 

Immunotoxicity. Metal fume fever is believed to be an immune response to zinc oxide. A correlation between the concentration of airborne zinc and the number of all types of T cells (helper, inducer, suppressor, and killer) in the bronchoalveolar lavage fluid of humans, possibly related to the onset of metal fume fever, was observed in an acute-duration inhalation study (Blanc et al. 1991). Impaired immune response in humans has been reported in an intermediate- duration oral study (Chandra 1984). No immune effects were observed in mice after oral exposure to zinc (Schiffer et al. 1991). There is some limited information to suggest that the immune system is a target of zinc toxicity. A battery of immune function tests after inhalation, oral, and dermal exposure to zinc compounds would be useful in determining if zinc is immunotoxic. 

Epidemiological and Human Dosimettv Studies. Acute high-level exposure to zinc by inhalation resulted in respiratory irritation and metal fume fever (Blanc et al. 1991 Hjortso et al. 1988 Johnson and Stonehill 1961 Linn et al. 1981 Schenker et al. 1981 Sturgis et al. 1927). Welders are a subpopulation of workers who have a high potential for exposure to zinc oxide. Most of the available studies did not report exposure levels or used a small number of subjects. Studies that correlate occupational exposure to zinc with health effects would be useful. A number of human oral exposure studies have shown that excess levels of zinc can result in anemia, pancreatic damage, decreased serum HDL cholesterol levels, and immunotoxicity (Black et al. 1988 Chandra 1984 Hooper et al. 1980). There are insufficient data for establishing dose-response relationships. 

Metal fume fever is an old syndrome that is quite well known, not so much by doctors, but by those who are especially at risk of suffering from it, such as welders or other workers in metal trades (Blanc 1993). The most frequent and best documented cause of metal fume fever is that caused by heating zinc. Zinc fumes, which oxidize to fine particles of zinc oxide (ZnO), are produced, for instance, when zinc is smelted to make alloys, when zinc-containing scrap metal is molten, when metal surfaces are sprayed with zinc or when galvanized steel is welded or cut. Metal fume fever occurs when the fumes are not properly exhausted, which is often the case when these jobs are done in enclosed spaces. Both freshly formed zinc fumes and fine zinc oxide dust have the ability to cause metal fume fever. 

Blanc P, Boushey HA (1993) The lung in metal fume fever. Semin Respir Med 14 212-225... 

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