نشریه طب کار
سال هشتم شماره 4 (پیاپی 25، زمستان 1395)

Silica dust is one of the most dangerous substances in the workplaces inducing a respiratory disease. Inhalation of silica particles at high levels can cause silicosis, a special form of interstitial lung disease. One way to monitor and control the effects of silica dust on workers is the study of changes in spirometric parameters. This study aimed to investigate the changes in spirometric parameters of workers exposed to silica dust in a glass-manufacturing plant in a 3-year period.
In this study, spirometric parameters of 200 workers were assessed in three consecutive years (1391-1393). The effects of smoking as well as changes in FVC and FEV1 were examined in different working groups with different exposure levels. The data were analyzed by SPSS ver. 18.
The results didnt show a significant difference among various working groups with different level of exposure during follow-up period. The changes between smokers and non-smokers were not significant as well.
It is concluded from the results of this study that the effect of silica dust on the spirometric parameters of the workers participating in this study was minimal.

Occupational infection with blood borne pathogens is a major public health problem in the world and despite this fact, needle stick injuries are not important for many health care workers and they don’t follow them. The aim of this study was to determine the prevalence of injury with needle and cutting objects in the service personnel of educational hospitals in Yazd.
This cross-sectional analytical study was conducted in educational hospitals in Yazd. 170 service personnel were enrolled in this study. Data were collected using a questionnaire included demographic and background data, history of the injury with a needle or cutting objects and information on knowledge, attitude and performance of injury with a needle. Data were analyzed by SPSS software using Student's T test and logistic regression analysis.
In this study, 45.5% of the personnel had experienced at least one injury with sharps; 78.1% of people reported that after exposure to these injuries, have visited a doctor. Comparison of knowledge in two groups showed that knowledge in subjects with injury was lower than subjects without injury. Although perceived risk in the group with injuries was more than the group without complications, but this difference was not significant. Needle stick injuries were lower in people with higher work experience than those with less experience.
Needle stick injuries were high in hospital service personnel. To prevent these injuries, educational programs should be a priority.

In every time and place, accidents can cause damages or injuries to people, property, community and organization reputation. With respect to this point that accidents occurred in laboratories of our country, this study aimed to assess the hazards in laboratories and workshops of Isfahan University of Art and also the implementation of interventions to increase the safety level in these places.
This is a cross-sectional study. After initial evaluation of all workshops and laboratories of the Isfahan University of Art, 4 workshops and laboratories with high potential level of hazards were selected for further study. Then, for quantitative assessment of hazards made a 130-question assessment checklist was prepared based on OHSAS 18001. After performing quantitative assessment of hazards and prioritizing them based on the results of this evaluation, interventions were implemented to decrease hazards and increase the safety level. Finally, quantitative assessment repeated and efficacy of interventions has been identified.
Based on the quantitative assessment according to evaluation checklist score, the percentage of general hazards in target sites was 20.8 to 45.4 % (Mean = 35.5, SD=9.2). Lack of safety supplies, equipment and signs with 31% and deficiency of safety procedure with 26 % were the most important factors corresponding to evaluated safety risk levels. Two interventions were implemented, including designing and installing safety signs and safety training.
After the educational and safety interventions, total hazards decreased from range of (%20.8 - %45.4) to range of (%15.4 - %32.3). According to the low cost of the implementing the interventions, the mean overall safety level is decreased (10.6%) thus increasing the safety level is acceptable.

Ergonomic problems and inadequate lighting are the causes of increased prevalence of musculoskeletal disorders in the workplace. The present study was conducted to evaluate lighting in carpet weaving workshops in Bijar and its association with musculoskeletal pain among female carpet weavers.
In this descriptive cross-sectional study, 104 Carpet weaving workshops were randomly selected with 180 carpet weavers. Illuminance was measured based on the models presented in Illuminating Engineering Society (IES) using a Hagner luxmeter in 76 cm height from the ground. Local illuminance was measured in horizontal and vertical weaving level. By using body map and pain scale, site of pain and pain severity during the last three months were gathered. RULA method was used to evaluate weavers work posture. Data were analyzed by SPSS 16 and statistical analysis was performed applying linear and logistic regression models.
Results revealed that only daily working hours were associated with musculoskeletal pain severity in carpet weavers (P=0.023). The average of artificial and minimum of local illuminance in horizontal and vertical weaving level (þP There was no direct significant relationship between general and local illuminance with musculoskeletal pain and its severity. Considering statistical correlation between poor lighting and awkward posture, it seems reforming artificial and using local lighting systems in workshops can improve posture and consequently prevent musculoskeletal disorders caused by poor lighting.

Noise-induced hearing loss (NIHL) is a major problem in industrialized and developing countries. Trend of industrialization and lack of proper protective equipment lead to an increased frequency of noise-related disorders especially NIHL. This study was conducted to investigate noise pollution and the frequency of NIHL in workers of one of the ceramic industries.
In a descriptive cross-sectional study, 155 tile workers were studied in 2015. Mean of age and working experience in participants was 29.45± 6.8 and 5.3 ±3.65 years, respectively. Sound pressure level in different sections of ceramic industry were measured using Brüel & Kjær sound level meter. Pure tone audiometry of air conduction was performed in both ears at frequencies 0.5, 1, 2, and 4 kHz. Hearing threshold higher than 25 dB at different frequencies was defined as hearing loss.
Mean of hearing threshold was 20.06 ±7.64 dB in right ear and 17.46 ±8.7 dB in left ear. Total hearing threshold was 17.9 ±8.04 db. About 18.7% of subjects suffered from NIHL in the right ear and 10.3% in the left ear. A significant relationship was found between work experience, job, lack of using proper protective equipment and hearing loss.
In conclusion, the rate of hearing loss among tile workers was high, hearing loss was more frequently seen in right ear than left ear.

Failure Mode Effect Analysis (FMEA) method used To identify the defects of the parts of a machine or a manufacturing process that includes several machines. The aim of this study was to compare a variety of prioritized control measures in reducing the number of risks in one of the edible oil factories.
This was a longitudinal and interventional study that carried out in one of the edible oil factories in Tehran province in 1393. After an initial assessment by an expert team, corrective solutions were implemented and Risk Priority Number (RPN2) was obtained. Data were analyzed using SPSS version 23.
In the studied industry, 73 risks in five major units of the factory were identified by using the Failure Mode Effect Analysis (FMEA) risk assessment method. The highest risk priority number (RPN) was 80 and the lowest was 4. The highest possibility of danger was related to the factory installation unit. Possibility of danger in this unit before and after the interventional actions was 4.5 and 3.25, respectively. The highest amount of hazard severity was related to the tool making unit. The mean of severity of dangers in this unit before and after interventions were 4.75 and 3 respectively. There was a significant difference before and after the intervention (p According to the results of this study, it can be concluded that failure mode effect analysis (FMEA) is a very useful evaluation method that focuses on high risk processes.

One of the main causes of urban noise pollution is traffic noise, which causes a variety of physical and mental effects, sleep disorders, hearing loss, and quality of life. The purpose of this study was to assess the noise pollution caused by traffic and its effects on sleep disorders and the people’s quality of life in Shiraz city.
This descriptive and analytic study conducted on 280 residents in heavy traffic and low-traffic areas of the city that selected according to the sampling method. Data collection included: quality of life questionnaire (WHOQOL: BREF), Herzberg sleep disorders questionnaire (PSQI) and by the CEL-440 sound level meter. Data analysis was performed using T-test, Chi - square and Pearson's correlation coefficient.
There was a statistical significant difference between traffic noise levels and sleep disorders in people nearby the low traffic boulevards (P The traffic noise level in low and high traffic areas in Shiraz city was higher than the standard levels that lead to increasing the sleep disorders and decreasing the quality of life of people.

Dentistry is regarded as a dangerous job because of some developing health problems such as pain, joint stiffness, etc. Some the risk of factors, including poor posture of the body while working. could be effective to create problems. The aim of this study was to investigate the ergonomic awareness of principles and its operation by the dentists in Yazd city.
In this cross-sectional study was performed on 159 dentists, who are up to 60 years old with at least one-year work experience. A questionnaire was implemented consisting of three sections: outbreak of musculoskeletal disorders, dentist's knowledge of ergonomic principles and recording the ergonomic principles followed by the dentist during the operation.
Among the participants in this study, 63.5% had regular exercise, %27 had twitch between two visits, %27 used direct sight, %89.9 had job satisfaction, and %73.6 were familiar with ergonomic principles, from which %28.9 reported the musculoskeletal disorder experience that it was more prevalent among females. The most common types of disorders were related to tingling and stiffness of limbs, from which the neck pin ranked first. The mean of awareness score and the mean of proper operation were reported 22.3773 ± 5.7154 and 16.8867 ± 5.9154, respectively.
In This study, there is a significant relationship between the awareness score and the level of following proper ergonomic principles. Thus, raising the awareness level of dentists from the ergonomic principles and following them could prevent musculoskeletal disorders.