Occupational asthma associated with bleached chlorine-free cellulose dust in a sanitary pad production plant.

BACKGROUND: Cellulose is an insoluble plant polysaccharide produced from soft-wood pulp. Although chronic respiratory effects associated with high cellulose-based dust levels have been previously described, occupational asthma has not. A 37 year old machine operator in a sanitary pad production factory presented with new-onset work-related asthma symptoms for two years.

METHODS: The worker underwent clinical, pulmonological and immunological (skin prick tests, serum specific IgE determinations) evaluation using standardised procedures. The cellulose product was subjected to scanning electron microscopy (SEM) examination. A specific inhalation challenge test performed with the cellulose product ensured that dust concentrations were kept below 5 mg/m3 .

RESULTS: The subject was not atopic and did not have elevated IgE to pine wood or xylanase. The cellulose product appeared to be free of protein contaminants on SEM. The Work Effect Index computed on serial PEF recordings was elevated (WEI = 3.8).Specific inhalational challenge with the cellulose product dust revealed a late bronchial response (39% drop in FEV1 at 3 hours post challenge).

CONCLUSION: This is the first reported case of occupational asthma to a cellulose fibre product. A non-specific immune reaction or irritant response seems likely. These fibres may therefore not be biologically inert. The occupational exposure limit of 10 mg/m3 generally used for cellulose dust appears to be non-protective.