Respiratory toxicity of raw materials used in ceramic production.

The main purpose of this study was to assess the pulmonary reactions associated with exposure to raw materials used in ceramic production (RMCP). This was a cross sectional study in which 33 male workers with current exposure to RMCP and 20 healthy male unexposed workers (referent group) were interviewed and respiratory symptom questionnaires were administered to them. Furthermore, they underwent chest X-ray and lung function tests. Additionally, personal dust monitoring for airborne inhalable and respirable dust was carried out at dusty areas of the industry. To determine the chemical composition, possible silica phases and SiO(2) contents of dust samples, they were analyzed by both X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques. Demographic and socioeconomic variables of both groups were similar, except that referent individuals were, to some extent, older and heavier than their exposed counterparts. Personal dust monitoring showed that the concentrations of inhalable and respirable dust were very high and dust contained large amounts of crystalline silica. Additionally, respiratory symptom questionnaires revealed that exposed workers, compared to their unexposed counterparts, had higher prevalences of cough, wheezing, phlegm and shortness of breath. Likewise, significant decrements in some parameters of pulmonary function were noted and most of the exposed subjects showed abnormalities in their chest radiographs. These data provide further evidence in favor of the notion that exposure to RMCP, probably due to their silica contents, is associated with respiratory symptoms, radiographic abnormalities and functional impairments.