نشریه طب کار
سال پنجم شماره 4 (پیاپی 13، زمستان 1392)

Prevalence of respiratory symptoms and lung function impairments among Darab ginning factory workers Masoud neghab، Morteza nowroozi sarjoeeye Exposure to cotton dust and its bioaerosol contaminants is the major cause of byssinosis. This study was conducted to determine the prevalence of respiratory symptoms and acute and chronic ventilatory disorders among Darab ginning factory workers. In this cross sectional study the paremeters of pulmonary function and prevalence of respiratory symptoms were measured by portable medical spirometers and standard respiratory symptoms questionaires، respectively. The exposure group were qualified workers of one of Darab ginning factories and referent subjects were selected among clerical staff of Shiraz university of medical science. Data analysis was performed using spss version 19. In this study the prevalence of respiratory symptoms such as: cough، phlegm، wheezing، chest tightness and byssinosis were significantly more common in exposed group than in the referent subjects (p<0. 05). Additionally، some parameters of pulmonary function such as: VC، FEV1 and FEV1/FVC% in the exposed group were lower than the control group. Mean changes in all lung function parameters except FVC signigicantly reduced after 8-hour shift in the exposed group (p<0. 05). The results of this study indicate that seasonal short-term exposure to cotton dust and its bioaerosol contaminants is associated with byssinosis، respiratory symptoms and lung function impairments.

People spend many times a day at work and they mostly do their work using computer. Today، computers are an integral part of the workplace، especially in office environments. The purpose of present study is to explore visual discomfort among office staff of Tehran university of Medical Sciences.

This is a cross-sectional analytical study and was done in 2012. Sample size was determined 150 people by simple random sampling. Data collection methods in our study were two questionnaires including demographic information questionnaire and Conlon questionnaire that is applied for measuring visual discomfort. Using SPSS. 18، descriptive statistics (like frequency counts، percentage distributions) and inferential statistics like Pearson correlation coefficient، student''s T-test and variance analysis were done for data analysis.

Results showed that 70% of subjects had the medium visual discomfort. It was found a significant correlation between visual discomfort and age and work experience (Pearson test: r=0. 181 and Pvalue=0. 042) and also there was a statistically significant relationship between visual discomfort and sex and education level (chi- square test: Pvalue=0. 025).

it is obvious that working with computer affected on visual comfort of office staff and it leaded to decrease visual comfort among them. Hence it is necessary for prevention of visual discomfort or/and exacerbating visual impairments to improve the lighting systems and teach the correct procedures of working with computer.

Substances found positive impact on the performance of athletes of different disciplines the body and the body attached to it does not matter and No deleterious effects on multiple organ systems، the main concern nutrition experts، is. One of the recent ones are in scientific circles as a complement sodium bicarbonate. twenty men participated in the investigation and divided into two groups randomly subjects completed two trials of Wingate test in two groups. After the first Wingate test they received either sodium bicarbonate. 300 mg/kg body weight، or placebo، water. The blood lactate level was measured by lactometer following each test Subjects participated in the second Wingate test that 70 min after ingestion of two substances The first one being measured by lactometer and the second one by analysis of monitor Wingate test (Monark). A significant relationship was observed between consumption sodium bicarbonate and blood lactate level but no significant relationship between sodium bicarbonate and peak power and power drop capacity. Data analyzing indicated that in both groups There were not significant difference between the average of peak powercan and tired after the consumption sodium bicarbonate. but in comarision with control group، A significant reduction was observed in lactate level in labor group after consuption sodium bicarbonate.

Silica nanoparticles could enter the living animals and humans through inhalation، ingestion، injection and skin، exerting potentially adverse effects on health and environment. The aim of this experimental laboratory study was to evaluate toxicities of silica nanoparticles in the form of wire، rod and sphere with different sizes (20، 50 and 100 nm) on rat pulmonary cells after 6 and 24 hours of exposure، using from 3- (4،5-Dimethylthiazol-2-y1) -2،5diphenyltetrazolium bromide (MTT) and 3- (4،5-dimethylthiazol-2-yl) -5- (3-carboxymethoxyphenyl) -2- (4-sulfophenyl) -tetrazolium (MTS) cytotoxicity tests.

Two male Wistar rats were anesthetized، their blood was completely replaced with Crebs solution، and their lungs removed to be digested for preparation of single cell suspensions in medium culture. Cell suspensions were separately treated with the above-mentioned nanoparticles at concentration of 500 µg/mL and 37 ºC incubation، and cell viability was assessed after 6 and 24 hours.

This study showed that smaller (20 nm) nanoparticles had more cytotoxic properties than larger ones. Also، spherical nanoparticles induced more cytotoxicity compared with other forms. Longer (24 hours vs. 6 hours) exposure resulted in slightly more cell death.

Cytotoxicity of nanoparticles depends on their shape، size and exposure duration.

In the foam industries، workers are exposed to various chemicals and working with these chemicals without considering occupational safety and health considerations could lead to different harmful symptoms. Consequently، in order to control measures and reducing risk to acceptable level، it is necessary to assess the health risk of exposure to harmful chemicals by implementation of specific risk assessment techniques in the process industries. The purpose of this study was to assess the health risks arising from chemical exposures in a foam industry in order to identify high-risk occupations and provide guidelines to reduce the risk of employment. This cross-sectional study was conducted in the polyurethane foam industry in 2012. In this study 13 men were examined: the mixer operator jobs (4 men)، the operator Cutter (6 men) and repairs and maintenance (3 men). In order to assess the health risks of chemicals the proposed method by Singapore Institute of Occupational Safety and Health was used. First، job tasks and work process were determined and then different chemicals in each task identified and risk ranking was calculated in each job task by using of hazard and exposure rate. Finally، the risk level for each of the materials was obtained by interaction of these two parameters in the equation. The result showed that workers are exposed to 7 chemicals including toluene diisocyanate، polyethylene glycol، polypropylene glycol، ethylene diamine، tin acetate، methylene chloride، and calcium carbonate during their work in plant. Out of these 7 chemicals، the highest risk level was determined for toluene diisocyanate in the foam production operators (Cutter Operator). (risk=3. 67) Results showed that workers in the production unit exposed to high levels of toxic vapors of toluene diisocyanate and this leads to change in their spirometry parameters، especially decrease in the FVC and FEV1. Moreover، health risk assessment of harmful chemicals a applied، and appropriate method for job ranking by their risk level was used. These methods could be used for appropriate implementation and prioritization for control measures and reducing risk level to acceptable level.

Burnout is a syndrome that results of occupational stress، causing decreased work efficiency، increased absenteeism and health care costs، quality decline of medical services for patients and could lead to dissatisfaction them. The aim of present study was to identify burnout and influential environment factors on burnout among family physicians. In this cross-sectional study، 145 family physicians practicing in Khorasan Razavi were selected by systematic randomly method. Data were collected via questionnaires، personal informations، and Maslach burnout inventory (MBI)، work environment indicators and self report. Results were analyzed using descriptive and analytical tests by SPSS software version 16 (P<0. 05). The mean age of participants was 32/57±4/87، 37/2 % (54 persons) were male and 62/8 % (91 persons) were women with a work experience median of 39 months in the healthy team. Depersonalization and personal accomplishment dimensions were in moderate level and emotional exhaustion was in the high level. Work environment indicators had significant inverse correlation with emotional exhaustion and depersonalization and significant positive correlation with personal accomplishment. The severity of burnout is associated with work environment factors among family physician، and we could assist reduce their burnout via positive change in different domains of work environment.

expert judgments in combination with exposure models are used extensively in estimation of inhalational exposures in occupational environments. However، their reliability is not as good as conventional air sampling methods. The aim of this study was to investigate the applicability، weaknesses and strengths of Bayesian analysis in combination with SSA (Structured Subjective Assessment Method) and MEASE (Material Estimated and Assessment of Substance Exposure) and its comparison with air sampling data. the analytical cross sectional –study performed on a weighting، mixing and packing task in an inorganic processing industry. Air samples were taken and analyzed by gravimetric methods. Inhalation exposures were estimated by 3 occupational hygienists. Descriptive and Bayesian analysis were performed on data. all three methods guaranteed that the exposure is above exposure limit. There was no difference between means reported in methods (p=0. 435). However، SSA had higher variability in comparison with sampling. There was no difference between direct sampling and MEASE variability. Use of SSA as a prior in Bayesian analysis gives more conservative than MEASE method (category 4:0. 74 vs. 0. 54) SSA is a good choice as a prior distribution in Bayesian analysis. MEASE has not good results in comparison with SSA in inhalation exposure assessment. It seems that MEASE needs more validation.

One of the assumptions which not discussed in all methods of reliability analysis is that human performance depends on the conditions under which tasks and activities could performed. This condition could be related to both specific and environmental factors. In general، the performance shaping factors (PSFs)، or factors influencing performance (PIFs) returns the state to promote safety and reduce human error، so identify and evaluate these factors is considered as a necessity. This study is a case study in the control room. Three operational gas transmission companies has been implemented. To conduct this research، initially focused on the identification and selection of factors affecting the performance required for data collection، preparation and completion of a questionnaire، and finally the analysis was done using fuzzy logic. Analysis of the questionnaires showed that in the opinion of the control room operators، the quality of «number of simulation goals» and «available time» is acceptable، and «the adequacy of training and experience» is not acceptable. Identify and assess the factors affecting the performance of various industries using fuzzy analysis method is extremely useful to reduce human error.