Excessive demands on nurses may result in high rates of musculoskeletal disorders (MSDs

Work-related Respiratory Symptoms and Ventilatory Disorders among Employees of a Cement Industry in Shiraz, Iran: Masoud NEGHAB, et al. Occupational Health Department, School of Health, Shiraz University of Medical Sciences, Iran-Although the main hazard in cement processing is dust and respiratory tract disorders are the most important group of occupational diseases in this industry, evidence for associations between exposure to cement dust and either respiratory symptoms or functional impairment has not been conclusive. This study was, therefore, undertaken to more thoroughly examine the effects of occupational exposure to cement dust on the respiratory system. The study population consisted of a group of 88, randomly selected, male workers with current exposure to cement dust and 80 healthy male office workers without present or past history of exposure to dust that served as the referent group. Subjects were interviewed and were given respiratory symptom questionnaires to answer. They also underwent chest X-ray and lung function tests. Additionally, personal dust monitoring for airborne inhalable and respirable dust was carried out at nine different worksites. Moreover, X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques were performed to determine the silica phases and the SiO 2 contents of the dust samples. Levels of exposures to inhalable and respirable cement dust were estimated to be 53.4 ± 42.6 and 26 ± 14.2 mg/m 3 , respectively (Mean ± SD). Statistical analysis of the data revealed that symptoms like regular cough, phlegm, wheezing and shortness of breath were significantly (p<0.05) more prevalent among exposed workers. Similarly, chest radiographs of exposed workers showed various degrees of abnormalities including emphysematous changes, old calcified granulomas, emphysematous changes associated with inflammatory processes, evidence of chronic inflammatory processes, focusal calcification of the lungs and infiltrative changes. However, no significant changes were noted in the radiographs of the referent group. Furthermore, exposed workers compared to their referent counterparts showed significant reductions in the parameters of lung function. In conclusions, our data provide corroborative evidence further substantiating the contention that exposure to cement dust is associated with respiratory symptoms and functional impairments. (J Occup Health 2007; 49: 273-278)

BackgroundUnleaded petrol contains significant amounts of monocyclic aromatic hydrocarbons such as benzene, toluene, and xylenes (BTX). Toxic responses following occupational exposure to unleaded petrol have been evaluated only in limited studies. The main purpose of this study was to ascertain whether (or not) exposure to unleaded petrol, under normal working conditions, is associated with any hepatotoxic or nephrotoxic response.MethodsThis was a cross-sectional study in which 200 employees of Shiraz petrol stations with current exposure to unleaded petrol, as well as 200 unexposed employees, were investigated. Atmospheric concentrations of BTX were measured using standard methods. Additionally, urine and fasting blood samples were taken from individuals for urinalysis and routine biochemical tests of kidney and liver function.ResultsThe geometric means of airborne concentrations of BTX were found to be 0.8 mg m−3, 1.4 mg m−3, and 2.8 mg m−3, respectively. Additionally, means of direct bilirubin, alanine aminotransferase, aspartate aminotransferase, blood urea and plasma creatinine were significantly higher in exposed individuals than in unexposed employees. Conversely, serum albumin, total protein, and serum concentrations of calcium and sodium were significantly lower in petrol station workers than in their unexposed counterparts.ConclusionThe average exposure of petrol station workers to BTX did not exceed the current threshold limit values (TLVs) for these chemicals. However, evidence of subtle, subclinical and prepathologic early liver and kidney dysfunction was evident in exposed individuals.

In this study, a miniature stirred tank bioreactor was designed for treatment of waste gas containing benzene, toluene and xylene. Oxygen mass transfer characteristics for various twin and single-impeller systems were investigated for 6 configurations in a vessel with 10 cm of inner diameter and working volume of 1.77L. Three types of impellers, namely, Rushton turbine, Pitched 4blades and Pitched 2blades impellers with downward pumping have been used. Deionized water was used as a liquid phase. With respect to other independent variables such as agitation speed, aeration rate, type of sparger, number of impellers, the relative performance of these impellers was assessed by comparing the values of (KLa) as a key parameter. Based on the experimental data, empirical correlations as a function of the operational conditions have been proposed, to study the oxygen transfer rates from air bubbles generated in the bioreactor. It was shown that twin Rushton turbine configuration demonstrates superior performance (23% to 77% enhancement in KLa) compared with other impeller compositions and that sparger type has negligible effect on oxygen mass transfer rate. Agitation speeds of 400 to 800 rpm were the most efficient speeds for oxygen mass transfer in the stirred bioreactor.

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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.

OBJECTIVESThe possible adverse respiratory effects of airborne pollutants in sawmills have not been thoroughly investigated in Iran. Additionally, the extent to which workers are exposed to this organic dust and its associated bioaerosols has not been extensively quantified. Likewise, the predominant bacterial and fungal species associated with wood dust have not been characterized. The present study was undertaken to address these issues.METHODSOne hundred male individuals exposed to wood dust and 100 unexposed male subjects were investigated. They completed a standardized respiratory symptom questionnaire and underwent spirometry testing. Additionally, airborne concentrations of respirable and inhalable dust particles, bacteria, and fungi were measured.RESULTSThe mean concentrations of inhalable and respirable dust particles, bacteria, and fungi were found to be 2.44, 6.76 mg/m3 , 756.38, and 299.15 colony-forming units/m3 , respectively. The predominant Gram-negative bacteria in the sawmills included the Pseudomonadaceae, Klebsiella pneumoniae, and Rhinoscleromatis spp., and the predominant fungi consisted of the zygomycetes and Aspergillus spp. Respiratory symptoms were significantly more prevalent among exposed workers. Significant cross-shift decrements were noted in some pulmonary function parameters. Similarly, pre-shift spirometry results indicated that some pulmonary function parameters were significantly lower in the exposed group.CONCLUSIONSExposure to wood dust and its bioaerosols was associated with significantly higher prevalence of respiratory symptoms and both acute (i.e., partially reversible) and chronic (i.e., irreversible) decrements in the functional capacity of the lung. Additionally, the characterized bioaerosols did not differ significantly from those isolated in other parts of the world.

Background: Being exposed to cooking fumes, kitchen workers are occupationally at risk of