[Epidemiological study of respiratory disorders induced by occupational inhalation of talc powder in rubber factory workers in Shiraz]

ABSTRACT

Talc powder is extensively used as a lubricant in rubber industry. However the nature of its respiratory effects, if any, has not been thoroughly investigated. The purpose of this study was to assess the pulmonary reactions associated with occupational exposure to talc dust. This is a analytical study in which 97 talc- exposed workers and 110 unexposed employees as the reference group were randomly selected from a local rubber industry. Standardized respiratory questionnaires were administered to the subjects. They underwent chest X-ray and were examined by a specialist for any possible respiratory abnormality to be diagnosed. Furthermore, Pulmonary Function Tests [PFTs] were performed just before and after the work shift. Moreover, to assess the extent of exposure to talc dust, using standard methods, inhale able and reparable dust concentrations were measured in different dusty worksites. The data were analyzed by standard statistical tests using SPSS software. The average [mean +/- SD] age [years], weight [kg], height [cm] and duration of exposure to talc dust [years] for the exposed group were 35.8 +/- 6.75, 73.1 +/- 9.2, 173.2 +/- 5.9 and 11.79 +/- 5.3 respectively. The corresponding values for the non- exposed group were 36.1 +/- 6.87, 73.36 +/- 8.1, 172.2 +/- 5.7 and 0 +/- 0, respectively. Atmospheric concentrations of inhaleable and respirable talc dust were found to be 41.8 +/- 23.52 and 19.8 +/- 8.04 mg/m[3], [mean +/- SD], respectively. Talc exposed subjects had a significantly higher prevalence of respiratory symptoms. Similarly, PFTs revealed that exposure to this lubricating agent was associated with significant decreases in the mean percentage predicted of vital capacity [VC], forced vital capacity [FVC] and forced expiratory volume in the first second [FEV1]. Moreover, there was a sharp reduction in some parameters of pulmonary function such as VC, FVC and FEV1, over the work shift. Chest radiographs of exposed workers showed evidence of chronic inflammatory process. These results which are in full agreement with the preliminary observations support the notion that occupational; exposure to talc is associated with both acute and chronic respiratory disorders and induces bronchitis and interstitial lung disease