نشریه طب کار
سال نهم شماره 2 (پیاپی 27، تابستان 1396)

Several studies have shown that DNA damages increase the risk of diseases such as cancer. One of the tests that used to assess the damage to DNA is Comet Assay. In this study, the initial damage caused by exposure to traffic-related air pollution was studied.
In this analytic cross sectional study, 104 taxi drivers were selected in Yazd, Iran. Peripheral blood sampling was performed. Microscopic analysis was performed under 400 magnification fluorescent microscope. Imagej software was used for image analysis. Data were tested by Kolmogorov–Smirnov test and Mann–Whitney U-test. Correlation analysis was performed.
In this study, all the participants were male. The mean±SD of the age and experience of the study population was 45.8±11.59 and 11.31±8.67 years, respectively. There was no significant difference between smokers and non-smokers in comet parameters. There was no significant correlation between Comet parameters and workload. There was direct and significant correlation between all parameters of comet. There was a significant correlation between tail intensity parameter and age after elimination of the confounding the effect of smoking.
In the results of the present study, there was not shown any genetic damages in taxi drivers exposed to the traffic related air pollution. Also, there is no significant relationship between these damages and smoking.

Occupational hearing loss due to noise is completely preventable and using the hearing protection device is one of control proceedings by the workers expose the impermissible noise. Therefore, this study aimed to determine the effective factors on occupational hearing loss and also the effective factors on using hearing protective devices by the workers exposed to excessive noise.
In this cross-sectional analytical study, 100 workers exposed to excessive noise were selected through sampling method. Data collection tools were a demographic information questionnaire and BASNEF model constructs, which its validity and reliability were confirmed. Audiometry was performed and recorded for each employee. Data were analyzed by SPSS software, version 19.
The findings showed that the age and occupational history had a meaningful relationship to hearing threshold shift (p-value0.05). Also, there was a meaningful relationship between education and duration of using the hearing protection device (p-value0.05).
The results show that there is a relation between the training of BASNEF model and duration of using the hearing protection device; so this training should be considered in hearing protective programs.

The aim of the present study was preparing polymeric materials and nanocomposites based on nanoparticles of zinc oxide in normal cases the coated with gelatin and comparing them in terms of sound transmission loss in different frequencies.
This study was an experimental one. The materials used in the current study were included zinc oxide nanoparticles, polymer polyvinyl chloride (PVC) and the gelatin. The steps of this study were conducted in two phases; the first phase included: making molds and producing nanocomposites and the second phase determining the sound transmission loss in nanocomposites.
Sound transmission loss conventional nanocomposites showed that the highest percentage of the weight in the first and second sound transmission loss in dB in 500 Hz was 4.34. While in the third weight the percent of the nanocomposites, the lowest transmission loss equaled to 0.80 dB at a frequency of 2000 Hz. The results of sound transmission loss in coated gelatin nanocomposites showed that the weight percentage of the first and second was the highest transmission loss equaled to 3.01 dB at a frequency of 500 Hz; and in the third weight percent, the lowest transmission loss equaled to 0.55 dB at a frequency of 2000 Hz, respectively.
Comparing the sound transmission loss in nanocomposites zinc oxide and coated with gelatin normally suggests that the gelatine resulting in increased absorption and sound transmission loss is reduced.

Nowadays, shift-working is necessary in societies, but there is not attention to its effects on health and family life, particularly on the relationships in family, spouse duties and the parents’ responsibilities.
The purpose of this study was comparing sleep quality, marital satisfaction and maternal efficacy in work-shift women. The statistical population contained 200 women workers in the Food Industry of Hashtgerd, Iran, in 2015. The sampling was conducted in two steps. A list of women workers in packing department with the criteria of being married and having children (60 persons at night-shift and 60 persons at day-shift) were randomly selected and the questionnaires were distributed. Data collection tools were a three-part questionnaire containing demographic information, Pittsburg sleep quality and parenting self-efficacy questionnaires. A T parametric test was used for comparing the average of two groups and analysis of multivariate variance applied for comparing them in sub-scales of sleep quality. Homogeneity of variance and normal distribution of scores was evaluated.
Findings: The results showed that the average of maternal self-efficacy in workers of night-shift were significantly lower than workers of day-shift. There was a meaningful difference between two groups in appropriate sleep duration, sleep efficiency, sleep disorders, morning performance and the total score of sleep. The workers mean scores of night-shift in these factors and their problems were significantly higher than others.
According to sleep disorders and its complications in shift workers, it is suggested that the people who are more compatibile should be selected. Also, informing them about the effects of shift-work on their relationship with their spouses and children is necessary.

One of the pollutants that is developing in human life day by day is Magnetic field. In modern urban transport systems, diesel motors have been replaced with electric motors, working with alternating and direct currents, and leading to occupational exposure of drivers with magnetic fields. This study aimed to determine the urban train's drivers exposure with static magnetic fields and compare it with national occupational exposure limits.
In order to measure the train's drivers exposured with static magnetic field, several samples were selected from urban AC and DC and AC intercity trains, in the 1,2,4, and 5 lines of Tehran, Iran. After determination of the sampling location, static magnetic field was measured by three axes magnetic field meter (HI-3550), according to the standard IEEE std C95.3.1 and previous studies. In order to analyze the data, SPSS software (ver. 20) was used.
The maximum exposure of drivers was in DC trains- line 2- (0.52 mT), meanwhile, average exposure of AC trains driver (0.095 mT) was higher than DC trains driver (0.081 mT). The average magnetic flux density between different lines has not have significant differences. The highest levels of time-weighted average exposure were related to line 1 AC train drivers (0.06 mT).
Exposure of train’s drivers was 10 time higher than background level, indicating a significant exposure in this job. However, in none of the assessment situation, the whole body exposure of train’s drivers was not exceeded from National Occupational Exposure Level (TWA= 0.2 and ceiling= 2 T). Of course, it does not imply that this level of exposure is completely safe, because different studies have reported health problems even at lower values of the magnetic field.

Water and electrolytes are essential to maintain the health and performance in hot occupational environments. The aim of this study was to determine the effect of different drinks on indices HSSI, PESI and PSI under laboratory conditions.
This clinical trial study was conducted on 13 male students in hot and dry laboratory conditions, (40 ° C, humidity 30%). In 3 steps within 2 hours of interferences, water, the combination of water and lemon, and lemon juice in the amount of 400 cc for 4 times was given to the participants. Every 10 minutes from the beginning of exposure to the heat index, Heat Strain Score Index (HSSI), Perceptual Strain Index (PESI), Physiological Strain Index (PSI), heart rate and oral temperature were measured. Analysis of variance with repeated observations and post hoc test was used to analyze the data.
The results showed that the index of HSSI (P= Drinking leads to keeping and maintaining normal conditions in participants. Compared with water and the combination of water and lemon, lemon juice drink has the greatest impact in reducing the average scores in all three indicators.

The aim of this study was to determine the mediator role of anxiety and depression in relationship between attachment styles and job satisfaction among teachers.
The method of the present study was correlation. Statistical population in this research, included all of 210 teachers of Jajarm schools in 2015. Then according to Kerjcie and Morganʼ sampling table, 136 teachers (60 women and 76 men) were selected based on stratified random sampling method. Attachment styles questionnaire (Kulinz & Rid, 1990), General Health Questionnaire (Goldberg & williams, 1988), and Job Descriptive Index (Smith, et.al, 1989) were used in order to collect data. Gathered Data were analyzed by Pearson's correlation coefficient and path analysis using SPSS and AMOS softwares.
Results indicated that there was a negative relationship between attachment with anxiety and depression (P Safe attachment style increases the job satisfaction of teachers by decreasing anxiety. The ambivalent attachment style decreases the job satisfaction of teachers by increasing anxiety.

The approach of the present study was identification and control of incidents and occupational incidents before and after occurrence. Therefore, this study was conducted to investigate and compare the effectiveness of engineering and non-engineering control interventions on risk levels and health safety indicators in one of the ceramic industries.
The method of this study was pre-interventional and post-interventional. After identifying and initial assessment of risks by a team of experts and using the FMEA 6-D technique, corrective strategies were implemented using three methods of engineering control, non-mechanical and both methods; after 5 months of implementation of the interventions, the system was re-evaluated and RPN2 was obtained. Then, the levels of risk indicators before and after the implementation of various types of controls were investigated.
A total of 163 risks were identified in the industry at 8 units. The body production unit with the mean risk number 407 had the highest potential damage and the furnace unit with the lowest risk number of 261 had the least damage. The highest risk priority number (RPF = 570) was related to work at height and activity on the Ballmill Spray Platform. The highest efficacy after intervention was to reduce the probability of P=0.002 and simultaneous interventions. After the intervention, the unacceptable risk level (no. 34) reached an acceptable and moderate level.
The results of this study show that engineering controls have the greatest impact on decreasing probability indexes, non-engineering controls on improving the risk discovery, and simultaneous controls on reducing the severity of the risk. If cost and time are not mentioned by managers, the use of simultaneous control methods can be the best and most effective intervention strategy.