RESUMO
Background: Galvanization is the process of coating steel or cast iron pieces with a thin layer of zinc allowing protection against corrosion. One of the important hazards in this industry is exposure to zinc compounds specially zinc oxide fumes and dusts. In this study we evaluated chronic effects of zinc oxide on the respiratory tract of galvanizers
Method: 188 workers were selected from a galvanization plant, 71 galvanizers as exposed group and 117 workers from other departments of plants as control group. Information was collected using American Thoracic Society [ATS] standard questionnaire, physical examination and demographic data sheet. Pulmonary function tests were measured for all subjects. Exposure assessment was done with NIOSH 7030 method
Results: The Personal Breathing Zone [PBZ] air sampling results for zinc ranged from 6.61 to 8.25 mg/m[3]] above the permissible levels [Time weighted average; TWA: 2 mg/m[3]]. Results showed that the prevalence of the respiratory symptoms such as dyspnea, throat and nose irritation in the exposed group was significantly more than the control group. Decreasing in average percent in all spirometric parameters were seen in the galvanizers who exposed to zinc oxide fumes and dusts. The prevalence of obstructive respiratory disease was significantly higher in the exposed group
Conclusions: Results suggest that high workplace zinc levels are associated with an increase in respiratory morbidity in galvanizers