Pulmonary Function in Jute Dust-Exposed Workers: A Dose-Response Relationship

Abstract

Pulmonary Function in Jute Dust- Exposed Workers: A Dose-Response Relationship: Jie CHEN, et al. Department of Pneumoconiosis, China Medical University School of Preventive Medicine—Pulmonary function tests were carried out on 488 jute-exposed workers in a jute mill and 332 control workers. An industrial hygiene survey was also conducted. Most workers in the mill were exposed to dusts containing less than 6% silica, whereas a few workers were exposed to dusts containing approximately 10-16% silica. The cumulative dose of dust exposure [dust level (mg/m³)× exposure year (yr)] was used as an exposure index to relate pulmonary function injury in jute workers. The results showed that jute workers had lower percentages of predicted pulmonary function than those of control workers. As the cumulative dose of dust exposure increased, average levels of pulmonary function (FVC, FEV₁, MMF, V₅₀, V₂₅) in smoking male jute workers and V₅₀, V₂₅ in nonsmoking female jute workers significantly declined, and pulmonary function abnormalities (less than 80% of predicted FEV₁ or less than 70% of predicted V₅₀) significantly increased as the cumulative dose of dust exposure increased. Examination of the effects of dust exposure and smoking on pulmonary function injury showed that not smoking but jute dust exposure was a factor associated with the decline in pulmonary function; Moreover, smoking interacted with dust exposure in causing declines in FEV₁. Our results demonstrated that there is a dose-response relationship between dust exposure and pulmonary function injury in jute workers. Based on this dose-response relationship and by using the life-table method, an exposure limit for jute dust was proposed as 4 mg/m³.