ABSTRACT
One of the most ubiquitous polysaccharides cellulose, possesses physical and chemical properties suiting it to a variety of industrial applications. There has been a long history of safe occupational exposure to wood derived cellulose in the pulp and paper industries. In all industrialized countries, wood derived-cellulose is treated as a nuisance dust. Several epidemiology studies of the pulp and paper industry indicate that, in general, workers are at lower risk of lung disease than the general population. Elevations of lung disease noted when comparing one employee subgroup to another, have been largely attributed to smoking. The largest epidemiology study currently conducted by Johns Hopkins University, is a case cohort analysis to designed to determine if there is any potential for specific chemical exposures to be linked to lung disease, and to confirm the effect of smoking. Animal studies conducted to date have examined the effect of high dose lung exposure to different cellulose containing compounds (e.g., microcrystalline cellulose, cellulose insulation) in the lung. All studies used high dosed levels (>2mg/g lung), likely to exceed the lungs capacity to clear cellulose, and subsequently showed nonspecific inflammatory effects. Similar responses can be demonstrated for a variety of insoluble nuisance dusts at high exposure, whereas at sub-overload doses persistent inflammatory effects are not observed. Importantly, in a recent study we have examined the effects of low doses of various cellulose containing materials in the rat lung. The results show minimal transient inflammatory effects consistent with the effects of innocuous nuisance dusts.
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