The present study examined the effects of occupational exposure of a group of dentists to low levels of mercury. The study population consisted of 106 dentists and 94 general practitioners (referent group), from private and public clinics in Shiraz city. Subjects were requested to complete a questionnaire on demographic variables, suspicious symptoms of intoxication and work practices. Additionally, atmospheric and urinary concentrations of mercury were measured by Atomic Absorption Spectroscopy technique. The data were analysed by c 2 test, independent sample t-test and multivariate logistic regression analysis, where applicable. Both groups were similar as far as most demographic and socioeconomic variables, but age and number of personal amalgam fillings, were concerned. Median of atmospheric concentration of mercury was found to be 3.35 μg/m 3 . Likewise, the urinary concentration of mercury in dentists was estimated to be 3.16 μg/g creatinine. This value was significantly higher than that of the referent group. Similarly, analysis of the data revealed that neuropsychological, muscular, respiratory, cardiovascular and dermal symptoms were more prevalent in dentists. Our findings indicate that occupational exposure of dentists to mercury, even at low levels, is associated with a significant increase in the prevalence of symptoms of intoxication.

This study aimed to evaluate possible health effects associated with long-term occupational exposure to low levels of mercury vapors. Forty-six subjects exposed to mercury and 65 healthy unexposed employees were studied. The subjects were administered a questionnaire on experienced symptoms and underwent clinical examinations as well as routine biochemical tests. Atmospheric and urinary concentrations of mercury were measured, too. Environmental concentrations of mercury were estimated to be 3.97 ± 6.28 μg/m(3) and urinary concentrations of mercury in exposed and referent groups were 34.30 ± 26.77 and 10.15 ± 3.82 μg/dm(3), respectively. Additionally, symptoms such as somatic fatigue, anorexia, loss of memory, erethism, blurred vision and teeth problems were significantly more common among exposed individuals. These observations indicate that occupational exposure to mercury vapors, even at low levels, is likely to be associated with neurological and psychological symptoms.

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.