A study was conducted examining the effects of dust and fumes on lung function and respiratory symptoms in rubber workers. Lung function was studied in 70 curing workers at the start and end of a day shift at the beginning and end of the week and in 69 unexposed referents. A small decline in lung function associated with 10 years of exposure to an average dust level of 2.0mg/m3 was identified. No significant differences between workers and referents was seen in the prevalence of respiratory symptoms. The ratio of forced expiratory volume at 1 second (FEV1)/forced vital capacity (FVC) was significantly lower in rubbers workers than in referents. Multiple linear regression analysis demonstrated that cumulative dust exposure was negatively associated with the FEV1/FVC ratio, maximal midexpiratory flow, and the flow rate at 50% of the FVC after controlling for cumulative exposure, height, age, and smoking. Exposure to rubber fumes at levels of approximately 1mg/m3 inhalable dust and 260 micrograms/cubic meter cyclohexane (110827) soluble fraction was not related to cross shift or cross week decreases in pulmonary function. The expected excess loss of lung function for a 37 year old rubber worker exposed to a mean dust level of 32.6mg/m3/year was calculated to be 1.3% for the FEV1/FVC ratio and 163 milliliters/second for the maximal midexpiratory flow. The authors conclude that these results do not support the presence of acute obstructive effects in rubber curing workers.

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