نشریه طب کار
سال سوم شماره 2 (پیاپی 4، تابستان 1390)

Occupational exposures are among the common causes of respiratory diseases. Exposure to the natural fibers as cotton, hemp, flax, and jute can lead to some acute and chronic respiratory diseases among textile workers. One of the most important diseases related to natural fibers is byssinosis. This study was performed to assess and compare spirometric indices between textile workers with or without exposure to natural fibers in during a shift-work on the first day of the work week after a period of absence from work.

This is a cohort study on 320 textile workers in two groups: 160 textile workers exposed to natural fibers (case group) and 160 textile workers without exposure to natural fibers (control group). After filling a demographic questionnaire for all subjects, Across-shift change in spirometric indices was measured and compared between two groups.

According to the results of this survey, in all workers who are working in the textile industry has seen a drop in indices of spirometry during shift work. With the difference that rate decline in these indices in people with face to natural fibers is very significant. In these people decrement of FVC is 16.91% and in people who are not faced is 3.11%, and decline of FEV1 in people exposed is 3.12% while in people without exposure is 0.51%.

Results of this study was demonstrated that more decline in spirometric indices FVC, FVC%, FEV1, FEV1% among textile workers who exposed with natural fibers and two parameters include age and employment duration had significant effect on changes in spirometric indices.

Nowadays, working long hours and shift work are inevitable, even though these working schedules are associated with several physical and mental effects. Gastrointestinal complaints are common among their physical effects. Recent studies have shown organoprotective effect of melatonin in gastrointestinal tract. In this study we investigated gastric mucosal damage due to partial sleep deprivation and the possible role of melatonin in this damage. 24 male rats were assigned in two groups: 12 rats in control group with normal sleep and 12 rats in partial sleep deprivation group. For partial sleep deprivation, we used a slowly rotating cylindrical cage, which was rotating 23 hours a day for 14 days. Animals were food deprived in the last 24 hours of study. Finally, their stomachs were assessed grossly and histologically. We also performed ELISA assay for measurement of their serum melatonin. Mucosal damage was seen to some extent in both groups. Damage severity was significantly higher in partial sleep deprivation group (P<0.001). In addition, serum melatonin was significantly lower in partial sleep deprivation group (P<0.001). We conclude that partial sleep deprivation could induce gastric mucosal damage in rats. Even though serum melatonin was lower in partial sleep deprived rats. So we could propose that decreased serum melatonin might have a role in this damage.

Failure Modes and Effect Analysis (FMEA) is a systematic method for identifying the factors that a product or process encounter with them, and identifying their results and effects. The aim of this study is to evaluate the potential risks in different parts of the Shiraz refinery by using risk assessment techniques. This cross- sectional study was conducted in Shiraz Refinery and relationship RPN(Risk Priority Number) with tasks e.g. milling, welding, transportation handling and etc. were studied in this company, then results analysis by Excel software. The findings showed that transportation and handling and then external surface scraping achieved the highest of RPN before and after corrective measures (200,210) and (72, 84) respectively. While RPN for welding and drilling (punching the external surfaces) before and after corrective measures are (144,120) and (24, 36) respectively. But hazard severity curve show tasks with lower RPN in comparison with those have higher RPN are more important of injury severity. some of tasks e.g. handling, transportation and milling have high RPN and by using effective control measures can eliminate or control hazards. Then Failure Modes and Effect Analysis is a useful and efficient for hazard assessment.

Noise is a harmful environmental factor which may cause hearing loss, hypertension, and higher rates of occupational accidents and reduced production. Considering the various intensities and frequencies produced by industrial equipments, we assessed the effects of noise on hearing of tile industry workers.

This cross-sectional study was done on 372 workers exposed to noise level of ≥85 dB in a tile factory in Yazd. After clinical examination and completing the questionnaire, audiometry was done by an audiologist for all. Data was then analyzed using SPSS software.

Our data showed mean age and work duration was 32.2 ± 6.9 and 9.5 ± 6.4 years respectively. Mean hearing thresholds for both ears were higher in 4000 and then 8000 Hz, as well as in higher frequencies rather than lower ones. Also, left ear showed more sensitivity than right ear. There was a significant relationship between hearing threshold and age and work duration (p<0.001).

Our findings showed that exposure to noise in tile industry increases mean hearing thresholds in higher frequencies especially for 4000 Hz, while age and work duration are important factors.

A large number of workers all over the world work in shift work schedules. Shift work and especially night work can disturb normal body rhythm especially sleep-wake cycle. Nurses as a member of health care workers should work in days and nights. Shift work in addition to its effect on nurse’s personal life can affect his (her) alertness and can decrease productivity and eventually endangers patients’ life.

In this cross-sectional study nurses working in the hospitals of Shahid Sadoughi University of medical sciences were divided into two groups: shift workers (case) and fixed day workers (control). These groups were matched for age, and employment duration. All subjects were selected from different hospital wards. We used two questionnaires, a questionnaire about demographic data and Epworth sleepiness scale. Questionnaires were filled by the nurses under direct supervision of the researcher. Data were analyzed using SPSS (ver. 17) by T test and chi square test.

55 subjects were assessed in each group. Mean ESS point was 8.07 and 6.80 in case and control groups, respectively. This difference was statistically significant. Sleepiness was observed in 29.1% and 14.5% of cases and controls, respectively, but this difference was not statistically significant.

In all, sleepiness was not so common among nurses and in spite of higher frequency of sleepiness among cases; the difference was not statistically significant.

Workـ related traumas could involve thousands of workers worldwide, especially in developing countries. These injuries may lead to incapacitation of work forces and ultimately impose a large economic load on industry. Due to the lack of statistics about the orbital trauma incidence among Iranian workers, we decided to evaluate the effects of age on the incidence of the ophthalmic trauma. In a retrospective descriptive study, all medical files of the miners between 2003 and 2008 were assessed, and workـ related injuries were recorded. These with ophthalmic trauma entered the study. Finally the relationship between age and incidence of the trauma was evaluated. Chi- square was used for analysis. From 7100 occupational accidents, 377 cases (5. 3%) suffered from ophthalmic trauma. Ophthalmic trauma had been most frequently occurred among 50-59 year old. Subjects (25. 3%) and subjects under 20 years old were the second group (20. 4%). The lowest frequency observed in subjects older than 60 year old. These wasnt any statistically significant difference in the frequency of ophthalmic injuries in different years (P>0. 05). Accidents had been occurred mostly in the summer and between 8-10 A. M. Chi-square analysis showed a significant association between the age and frequency of trauma among miners (P<0. 05). More frequent ophthalmic trauma in aforementioned age groups may be due to lower physical strength in older ages and lower job experience in year ages. These were no reduction in the frequency of trauma in different years which may be due to failure in the development of safety in the workplace.

Tile workers are exposed to a lot of dusts and are susceptible to various pulmonary complications. This study was designed to evaluate the respiratory symptoms and lung capacities of tile workers. This was a retrospective, cross sectional study on 350 workers in different factory workshops. We assessed respiratory complaints and pulmonary function tests. Data were analyzed by SPSS using T-Test and ANOVA. Among respiratory complaint, dyspnea was the most frequent(22.9%), and cough(13.1%) and sputum production(5.4%) were in the 2nd and 3rd orders. There was a significant relationship between dyspnea and reduction in spirometric indices(P< 0.05),and there was a significant relationship between respiratory complaint and job title, frequency of respiratory symptoms were higher among foundry workers. It is clear that occupational exposures affect pulmonary function, performing pulmonary function tests may show lung term effect of these exposures.

Researches have shown that musculoskeletal disorders are among the most important occupational problems. Nowadays prevention of work-related musculoskeletal disorders is a necessity and national priority. This study was designed to identify the frequency of musculoskeletal disorders in food industry. In a cross-sectional study, workers from 10 job categories in a food industry were selected. 50% of workers in each job category were randomly selected and at last 92 subjects entered the study. Nordic questionnaire was used to assess the frequency of work-related musculoskeletal complaints and QEC method was used for job analysis. Mean age of workers was 36.36 ± 8.50 (range: 23-55) years. Mean employment duration was 11.17 (range: 1-30) years. 21.7% of subjects had experienced pain and discomfort in at least one of the 4 areas (neck, shoulder, low back, and hand) in the last 12 months. Among all musculoskeletal disorders, those presented in low back and shoulder had a significant relationship with employment duration (p = 0.01). This study showed that musculoskeletal disorders were more frequent in low back and hand regions.