THE EXPOSURE OF TOLUENE AND RESPIRATORY PROBLEMS AMONG AUTOMOTIVE INDUSTRY WORKERS IN SELANGOR

Abstract

ISEE-439 Aim: A cross sectional study was carried to determine the association between toluene in air and urinary hippuric acid (toluene metabolite), and pulmonary functions and respiratory symptoms among exposed workers in an automotive industry in Selangor. Methods: Workers in the paint shop were selected as the exposed group (N = 66) and a group of administrative workers (N = 42) was the control group. Respiratory symptoms were determined using a modified American Thoracic Society's questionnaire. Individual workers' breathing zones were sampled for toluene at the beginning and before the end of the work shift. Toluene was analyzed using gas chromatography. Measurements of pulmonary function were carried out with a spirometer. Urine samples were collected at the end of the work shift. Urine hippuric acid levels were analyzed by high performance liquid chromatography. Results: Respiratory symptoms most commonly experienced by the respondents were cough with phlegm (70.97 %); the least common symptom was shortness of breath (12.90 %). The prevalence of respiratory symptoms was significantly higher among the exposed group [cough (p< 0.001); cough with phlegm (p<0.001); chest tightness (p=0.003)]. The mean air toluene concentration was 1.44 ppm (SD = 4.47). A significant association was found between air toluene levels and chest tightness (χ2 =4.364, p=“0.037”). The exposed group had a significantly higher prevalence of abnormal FEV1% predicted, FVC% predicted and FEV1/FVC% predicted, than the comparative group. There were significant differences in the FVC% predicted (p=0.015), FEV1% predicted (p<0.001) and FEV1/FVC% predicted (p<0.001), between the two groups. ANCOVA analysis showed a significant difference in FEV1 (p<0.001), FEV1% predicted (p<0.001) and FEV1/FVC% predicted (p<0.001) between the two study groups, after adjusting for age, work duration, body mass index and smoking habits. The mean urinary hippuric acid concentration was 0.24 μg/g creatinine (SD = 1.40 μg/g creatinine). There was no significant correlation between urinary hippuric acid and any of the respiratory symptoms, lung function outcomes, or the air toluene levels. Multiple linear regression analysis showed that no variable significantly influenced the lung function tests and urinary hippuric acid concentrations. Conclusion: Exposure to organic solvents has significant chronic health effects, as indicated by the higher prevalence of respiratory symptoms and the reduction in lung functions, among the exposed group. The air toluene and urinary hippuric acid levels were not associated with the lung function results. Therefore, chemical compounds in the solvents, which have not been identified in this study, may have been associated with the respiratory problems.