[Subclinical neuropathy in workers occupationally exposed to n-hexane]

N-Hexane is widely used in the production of glues, lacquers, paints, plastics, and rubber products. Consequently, a significant potential for exposure to this toxic solvent exists in industrial settings. This study was undertaken to assess the neurophysiological abnormalities in shoe-makers occupationally exposed to n-hexane and determine whether these abnormalities have any correlation with important occupational parameters. Neurophysiological examinations of upper and lower extremities were made in 27 male-workers, and the results were compared with a sex- and age-matched reference group. In addition, the extent of exposure of individual workers and their urinary concentration of free 2,5-hexanedione were determined. Data were analyzed using the Statistical Package for Social Sciences [version 16.0. for windows]. The time-weighted average exposure to n-hexane and the mean urinary concentration of free 2,5-hexanedione were both lower than the respective TLV-TWA and Biological Exposure Index [BEI] values proposed by ACGIH. Although neurological examinations and nerve conduction velocities were normal, significant negative correlations were observed between the urinary concentration of free 2,5-hexanedione and the sensory nerve action potential [SAP] amplitudes for median [r=-0.67, p<0.001] and sural [r=-0.52, p<0.008] nerves. Reduced SAP amplitude for median and sural nerves appears to be the primary neurotoxic effect of 2,5-hexanedione and can be used as an appropriate indicator for screening subclinical peripheral neuropathy in n-hexane-exposed workers

[Assessment of Hematotoxic effects of occupational exposure to unleaded petrol]

Gasoline is a complex mixture of more than 500 hydrocarbons. The elimination of lead from petrol has been associated with the addition of significant amounts of hematotoxic monocyclic aromatic hydrocarbons such as benzene, toluene and xylene [BTX]. The main purpose of this study was to ascertain whether exposure to unleaded petrol, under normal working conditions, is associated with any hematotoxic response. This was a historical cohort study in which 200 subjects with current exposure to unleaded petrol from Shiraz petrol stations as well as 200 unexposed employees were investigated. Using standard methods, atmospheric concentrations of BTX were measured. Additionally, blood samples were taken from subjects for routine biochemical tests such as RBC, WBC and platelet count, Hemoglobin, hematocrit and RDW. The geometric means of airborne concentrations of BTX were found to be 0/24, 0/37 and 0/64 ppm, respectively. The results of blood chemistry tests showed that no significant differences exist between both groups as far as biochemical tests, but RDW and hematocrit, were concerned. The average exposure of petrol station workers to BTX did not exceed the current TLVs for these chemicals. Additionally, overt hematotoxicity is unlikely to be the outcome of exposure to unleaded petrol under the conditions described in our study.

[Toxic response of occupational exposure to ethylene oxide, with particular reference to its respiratory effects]

Ethylene oxide is used as a sterilizing agent in health care industries. The present study aimed to assess and recognize the nature of pulmonary reactions, if any, associated with occupational exposure to ethylene oxide and to investigate the prevalence of dermal, visual, neurologic, reproductive, hematologic, hepatic and renal disorders. Forty exposed and 47 unexposed employees were evaluated. Subjects were interviewed and standard respiratory symptom questionnaire as well as a questionnaire pertaining to symptoms of intoxication with this chemical were administered to them. Furthermore, parameters of pulmonary function were measured during exposure and a few days after exposure ceased. Additionally, blood samples were taken for CBC, liver and kidney function tests. moreover, atmospheric concentrations of ethylene oxide were determined by gas detector tubes. Respiratory symptoms such as cough and phlegm as well as dermal, visual and neurologic symptoms in exposed workers were significantly more prevalent p

[Sublicnial symptoms of intoxication associated with exposure to low levels of mercury by dentists]

Dentists are occupationally exposed to elemental mercury from placements of mercury-containing amalgam. Although many studies have been conducted on mercury intoxication, there is still widespread concern about possible ill effects of chronic low-level mercury exposure on dentists. The present study examined the effects of occupational exposure to low levels of mercury by a group of dentists. In this historical cohort study, subjects 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, symptoms experienced and work practices. Additionally, using standard' methods, atmospheric and urinary concentrations of mercury were measured. The data were analyzed by appropriate statistical tests. In univariate analysis, Chi-Square test was used to compare the prevalence of symptoms among both groups. Independent sample t-test and Mann- Whitney's U-test were used to compare the mean and median of quantitative data of both groups. Multivariate logistic regression analysis was used to adjust for potential confounders. Both groups were similar as far as most demographic and socioeconomics variables, but age and number of personal amalgam fillings, were concerned. Median of atmospheric concentration of mercury was found to be 3.35 micro g/m[3]. Likewise, the urinary concentration of mercury in dentists was estimated to be 3.22 micro g. creatinine. This value was significantly higher than that of the referent group. Additionally, analysis of the data revealed that subclinical symptoms of intoxication were more prevalent in dentists. Our findings indicate that occupational exposure to mercury by dentists, even at low levels, is associated with a significant increase in the prevalence of subclinical symptoms of intoxication

[Relationship between spirometry results and respiratory complaints to flour dust in flour mill workers]

Exposure to flour dust and related allergens is one of the most common causes of occupational airway disease [OAD] and occupational asthma [OA]. The main purpose of this study was to investigate the respiratory effects of exposure to high atmospheric concentrations of flour dust. This study was carried out in a local flour producing factory in Shiraz, in 1384. Sixty seven subjects [35 exposed and 32 non-exposed] were investigated. The prevalence of respiratory symptom as well as lung function capacities was evaluated. Additionally, atmospheric concentrations of flour dust were measured. The data were analyzed by Independent sample t-test, Chi-square or fisher's exact test and multiple linear regression. Atmospheric concentrations of dust exceeded current permissible levels. Additionally, exposed workers had higher prevalence rates of regular cough, productive cough, wheezing, phlegm and shortness of breath. Likewise, significant [p<0.05] decrements in the parameters of pulmonary function were noted. The findings of this study provide additional corroborative evidence in favour of the notion that after adjusting for age, smoking habits and other confounders, a strong association exists between exposure to flour dust and the prevalence of respiratory symptoms and functional impairments of the lungs

[Respiratory symptoms and functional impairments induced by occupational exposure to formaldehyde]

The main purpose of this study was to assess the acute and chronic effects of occupational exposure to low levels of formaldehyde on respiratory health. This historical cohort study was conducted at a local melamine-formaldehyde resin producing plant. The study population consisted of seventy exposed and 24 non-exposed [referent] employees. In this study, a questionnaire was used to evaluate and determined the prevalence of respiratory symptoms. Atmospheric concentrations of formaldehyde were measured at different areas of the plant. Similarly, using a spirometer, the parameters of pulmonary function were measured during exposure and a few days after exposure ceased. Atmospheric concentrations of formaldehyde marginally exceeded current permissible levels. Additionally, significant decrements in some parameters of pulmonary function, both during and after exposure were noted. However, a relative recovery in lung functional capacity observed following temporary cessation of exposure. Furthermore, exposed workers had higher prevalence rates of regular cough, wheezing, phlegm, shortness of breath, chest tightness and episodes of chest illness associated with cold. The findings of this study indicate that exposure to formaldehyde may induce respiratory symptoms, acute partially reversible and chronic irreversible functional impairments of the lungs

Respiratory health following long term occupational exposure to fiberglass dust

Despite the wide application of fiberglass, its respiratory effects have not been extensively studied. The purpose of this study was to further examine this issue among a group of workers occupationally exposed to this compound. This is a historical-cohort study in which the respiratory health of 49 workers exposed to fiberglass as well as 42 unexposed employees as the referent group from a local fiberglass industry was evaluated. A standardized respiratory questionnaire was used. The subjects underwent chest x-ray and were examined by a physician for any possible respiratory abnormalities. Furthermore, pulmonary function tests were performed just before the work shift. Moreover, to assess the extent to which subjects had been exposed to fiberglass dust, respirable dust concentrations were measured in different dusty work sites, using standard methods. The average age of the exposed subjects and the duration of exposure were 39.6 +/- 7.34 and 11.2 +/- 5.59 years, respectively. Atmospheric concentrations of respirable fraction of fiberglass dust in dusty work sites, namely Line and Tissue units, were found to be 44.5 and 6.27 mg/m[3], respectively. The prevalence of respiratory symptoms and abnormalities in the chest x-ray of the exposed and unexposed subjects was not significantly different. Lung function parameters, i.e., vital capacity [VC], forced vital capacity [FVC], forced expiratory volume in the first second [FEVi], and percentage ratio of FEV1 to FVC in the exposed workers were comparable with those of the control subjects. Significant associations between the length of exposure to fiberglass and age with FEV/FVC ratio were noted. The results support that exposure to fiberglass dust is unlikely to be associated with respiratory symptoms, abnormal radiographic changes or functional impairments of the lungs

[Cardiovascular adverse health effect of occupational exposure to licorice dust]

Prolonged use of licorice is known to cause headaches, hypertension, cardiac arrhythmias, edema, lethargy, shortness of breath, sodium retention and loss of potassium in healthy people. However, to best of authors' knowledge, to date, the potential adverse health effects of occupational inhalation exposure to licorice dust have not been examined. This study was, therefore, under look to address this issue. In this cross-sectional study, the individuals [30 workers] occupationally exposed to licorice dust at a licorice-producing plant in Shiraz were recruited. Similarly, 30 healthy male unexposed employees at a telecommunication industry, with identical demographic and socioeconomic substance served as control group. A pre-designed questionnaire was completed for both groups. Systolic and diastolic blood pressures were measured. Additionally, they underwent electrocardiography, clinical examination and blood chemistry test. To assess the extent to which subjects had been exposed to licorice dust, atmospheric concentrations of this aerosol were also measured in the plant. Data were statistically analyzed using INSTAT software. While there was no significant differences between exposed and control group as far as demographic variables are concerned, mean values for systolic and diastolic blood pressure of exposed subjects were significantly higher than those of the control subjects. Similarly, blood analysis revealed that serum concentrations of potassium ion as well as platelet counts were significantly lower in exposed subjects than controls. Analysis of the questionnaires also demonstrated that symptoms such as headache, lethargy and vertigo were more common in exposed subjects. No abnormal changes in electrocardiographs were noted in both the groups. Collectively, our findings provide evidence in favor of the notion that inhalation exposure, to high concentrations of licorice dust is associated with higher prevalence of headache, lethargy and vertigo as well as raised blood pressure and hypokalemia. Although none of these changes reached to a level with pathological significance. Additionally, these findings indicate that licorice induces mild thrombocypenia

Hearing impairment and hypertension associated with long term occupational exposure to noise

Noise induced hearing loss, a permanent bilateral hearing impairment due to long term exposure to high levels of noise, represents one of the most common occupational hazards. This historical cohort study was undertaken to evaluate the auditory effects of noise and to further examine the hypothesis that a link between noise exposure and hypertension exists. The study population consisted of 140 healthy male employees from a local petrochemical industry with a history of past and present exposure to noise and 140 matched healthy unexposed individuals from the same industry [reference group]. A questionnaire with 40 items concerning age, sex, weight, height, length of employment, workplace noise level, and history of hypertension was administered. Furthermore, the subjects were physically examined, their blood pressure was taken under normal resting position and all underwent audiometry testing. Similarly, sound pressure level and octave band analyzing in different stations of the workplace were carried out for every employee, and then Leq was calculated. The prevalence of hearing impairment in this study was 38.5% among the exposed and 7.8% among the unexposed group and the difference was statistically significant. Similarly, the prevalence of hypertension in the exposed group was significantly higher than that in the unexposed group. These findings provide corroborative evidence to further substantiate the notion that exposure to noise is associated with hearing impairment. They also support the proposition that long term occupational exposure to noise appears to be a risk factor for arterial hypertension

[Evaluation of respiratory disorders associated with occupational inhalation exposure to raw materials used in ceramic production]

The main purpose of this study was to assess the pulmonary reactions associated with occupational inhalation exposure to raw materials used in ceramic production [RMCP]. Thirty three male workers with current exposure to RMCP and 20 healthy male unexposed employees, with almost identical demographic and socioeconomic status were interviewed and respiratory symptom questionnaires were administered to them. Furthermore, they underwent chest X-ray and lung function tests. Additionally, personal dust monitoring was carried out at dusty work sites. To determine the chemical composition, possible silica phases and SiO2 contents of dust samples, they were analyzed by X-ray diffraction [XRD] and X-ray fluorescence [XRF] techniques. Atmospheric concentrations of dust, that contained 69% SiO[2], exceeded current permissible levels. Additionally, exposed workers had higher prevalence rates of regular cough, wheezing, phlegm and shortness of breath. Likewise, their chest radiographs showed some degrees of abnormalities. Furthermore, significant reductions in some parameters of pulmonary functions of exposed workers were noted. The findings of this study indicate that a strong association exists between exposure to RMCP, prevalence of respiratory symptoms, abnormal changes in chest radiographs and functional impairments of the lungs

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

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

Problems related to shiftwork for health care workers at Shiraz University of Medical Sciences

A cross-sectional study of shiftwork-related problems was carried out among health care workers at hospitals of Shiraz University of Medical Sciences, Islamic Republic of Iran. Data on personal details, shift schedule and adverse effects of shiftwork were collected from 432 randomly selected subjects by questionnaire. Sleep, social and subjective problems were more prevalent in shiftworkers than day workers. Irregular shiftwork schedules caused more social and subjective problems, as well as work dissatisfaction. Voluntary selection of shiftworking produced fewer health problems

Home accidents in rural and urban areas of Shiraz, 2000-02

Data on home accidents for a 3-year period [2000-2002] were collected from health houses, health centres and hospitals involved in a home accident prevention programme in Shiraz, Islamic Republic of Iran. A total of 15 402 accidents were registered, with a mortality rate of 1.3%. Accidents were more common in women than in men [52.1% versus 47.9%] and urban than rural areas [66.3% versus 33.7%]. Burns [66.5%], followed by injuries due to sharp objects [11.3%] were the most common causes. Accidents were more prevalent in children aged under 5 years, followed by 5-9 and 15-19 years of age