مجله بهداشت و ایمنی کار
سال ششم شماره 3 (پاییز 1395)

Lead exposure is considered as a global health problem. The irreparable harmful effects of this heavy metal on human have been proven in various studies. Comparing to general population, workers in related industries are more exposed to lead. Several studies have investigated lead occupational exposure and its biological evaluation in Iran; however there is no overall estimate. Thus, the present study was conducted to determine the occupational exposure to lead and its biological evaluation in Iranian workers, using systematic review and meta-analysis.
Material and This study was carried out based on information obtained from databases including Magiran, Iranmedex, SID, Medlib, Trials Register, Scopus, Pubmed, Science Direct, Cochran, Embase, Medline, Web of Science, Springer, Online Library Wiley, and Google Scholar from 1991 to 2016, using standard key words. All of the reviewed papers which met the inclusion criteria have been evaluated. Data combination was performed according to Random Effects Model using Stata software version 11.1.
In the 34 qualified studies, the mean blood lead level (BLL) concentration in Iranian workers was estimated 42.8µg/dl (95% CI: 35.15-50.49). The minimum and maximum BLL were belonged to west (28.348µg/dl) and center (45.928µg/dl) regions of Iran, respectively. Considering different occupations, the lowest mean value was reported in textile industry workers (12.3 µg/dl), while the highest value was for zinc-lead mine workers (72.6 µg/dl). Mean breathing air lead level of Iranian workers reported in 4 studies was estimated 0.23 mg/m3 (95% CI: 0.14-0.33).
According to the high concentration of BLL and breathing air, it is recommended to increase protective measures and frequent screening. Scheduled clinical and paraclinical examination should also be performed for workers.

Noise pollution in urban areas has been recognized as a major problem. Since hearing damages are the main concern of noise exposure, other physical and psychological effects should not be ignored. Noise-induced annoyance and consequently its side-effects, such as fatigue and loss of concentration, would increase the probability of human errors occurrence and occasionally irreversible occupational accidents. This matter show the importance of noise exposure level from the standpoint of both community health and workplace safety.
Material and This cross-sectional study was conducted to investigate the annoyance caused by air transportation noise in tehran, 2014. In this sense, a sample of 200 individuals were selected from residential and nonindustrial noise-exposed population in four southwest regions in Tehran. Following, the study questionnaires including annoyance (Recommended based on ISO 15666-2003), visibility of airplane, noise perception, and demographic variables were distributed and completed by the participants. Data obtained from Integrated Noise Model (INM) and geographic coordinates of measurement stations, recorded by Glopal Positioning System (GPS), were entered into the GIS software in order to estimate air traffic noise.
The present study showed that the equivalent sound level of all regions during night, the day average sound level only in the Simetry Jey area, and the average night noise level in all regions except Dorahi Ghopan were more than the acceptable level; and the most precentage of people with high annoyance was belonged to night annoyance rate. On the other hand, the correlation between day level (DL) and day annoyance rate (P=0.01, R=0.142), night level and night annoyance rate (P=0.004, R=0.334), and Day-Night Average Sound Level (DNL) and the day-night annoyance rate (P Adopting management srategies for reduction of number of night flights or engineering measures such as improving construction to decrease the rate of receiving noise by exposed people can have a positive considerable effect on declining noise pollution and individuals’ annoyance rate.

Regarding development of several thermal indices and limitations of each, in this research applicability and validity of temperature- humidity index (Humidex) were examined against the standard heat index, Wet Bulb Globe Temperature -WBGT, as well as tympanic temperature of subjects.
Material and This cross-sectional study was done on 163 subjects at spring and summer (2013) in outdoor jobs of arid and semi-arid climates of Iran. Environmental parameters as well as tympanic temperature of subjects were measured simultaneously and then heat indices were determined. Data were analyzed using linear correlation charts and Kappa coefficient of agreement by means of SPSS software version 20.
A strong correlation was obtained between WBGT and Humidex in both arid and semi-arid regions (r>0.98), while the correlation between Humidex and tympanic temperature was moderate (r=0.5-0.8). Based on the obtained Kappa value, the agreement coefficient between Humidex and WBGT was 0.878. This value was obtained equal to 0.226 for the Humidex and tympanic temperature.
The results of this study showed that Humidex can be applied as an appropriate substitute for the WBGT index. However, if evaluation of environmental condition with low air temperature or very hot situation is considered, relying only on the Humidex results will not provide a realistic estimation of thermal strain imposed to individuals.

Resilience engineering (RE), as a new approach in the system safety domain, is intended to preserve the performance of socio-technical systems in various conditions; and accentuates the positive activities instead of the failure modes. The aim of this study was to develop a new framework for safety assessment on the basis of RE, using the Fuzzy Analytical Hierarchy Process (AHP) method.
Material and Current study is an analytical cross-sectional survey performed in a petrochemical industry. Initially, six RE indicators were selected, including top management commitment, just culture, learning culture, awareness, flexibility and emergency preparedness and accordingly an assessment framework was established. Then, the selected RE indicators were evaluated and validated by experts in a specialized panel. Following, an indicator was proposed named “resilience early warning indicator”. Finally, the RE indicator score of the total process was determined using the fuzzy evaluating vector.
Findings revealed that top management commitment and learning indicators have the most and the least effects on the RE level of the process, respectively. Besides, the flexibility (C3) indicator was located in orange early warning zone (OEWZ) while other indicators were positioned in the no early warning zone (NEWZ). Furthermore, the overall resilience level of the process was evaluated as level III (NEWZ).
Management commitment and emergency preparedness are two main indicators of RE and can carry out the most important effect for remaining the RE in the NEWZ level.

Limited studies have been done to evaluate the whole-body vibration (WBV) exposure experienced by Taxi drivers. Therefore, the aim of this study was to evaluate the exposure to whole body vibration and repeated shocks in urban taxi drivers and also to compare different methods of evaluation in this job environment.
Material and Measurement and evaluation process were conducted in accordance with procedure of the ISO 2631-1 and ISO 2631-5 standards. The measurements were done by SVAN 958 Sound and Vibration Analyzer and using tri-axial accelerometer centered on the contact surface between the seat and the driver in 9 taxis.
The measurements done according to ISO 2631-1 method showed greater risk compared to Daily Equivalent Static Compression Dose, Sed, presented in ISO 2631-5. Calculated daily exposure durations for exposure action level in root-mean square, vibration dose value, and daily equivalent static compressive stress methods were 4.55, 3.54 and 31.70 hours, respectively.
The large differences in estimated exposure durations of action limits and permissible limits resulted by different methods reflect the inconsistency of the selected evaluation methods. Therefore, future research is necessary to amend the limits presented in the standard.

In recent years, a growing attention has been paid to assess the physical characteristics of rich and poor urban districts to understand social health differences. Urban districts environment play a major role in health of the residents. Previous few studies have considered some aspects of limited neighborhood environment. The current study was designed to investigate the reliability of the Neighborhood Health, Safety and Environment (NHSE) tool in one of Tehran city neighborhoods.
Material and Dimensions and related items of the NHSE were extracted based on the previous studies and interviews with city experts. Five observers completed the NHSE in a selected neighborhood in order to test inter and intra-rater reliability of the tool. Data analysis was done using the Cronbach’s alpha, Interclass Correlation Coefficient (ICC) and kappa coefficient.
The ICC and Cronbach’s alpha were estimated 0.86 for all dimensions of the NHSE. The calculated kappa values were in the range of 57%-66% for inter-rater reliability and 0.47-0.62 for intra-rater reliability.
The NHSE tool was shown to have a desirable inter and intra-rater reliability and a good level of internal consistency for assessing the health, safety, and environment (HSE) of the neighborhoods.

Provision of high quality nursing care for patients, has made patient safety culture as an important issue for improving the quality of health care in the country. This study aimed to determine the relationship between nurses’ job satisfaction and patient safety culture in hospitals of Rasht city, Iran.
Material and This research is a descriptive-analytical, cross-sectional, and field data collection study. Nurses working in public and private hospitals in Rasht City comprised the study population, of whom 322 subjects were selected randomly as the study sample. The Wakefield questionnaire and the Agency for Healthcare Research and Quality questionnaire were employed to investigate nurses’ job satisfaction and patient safety culture, respectively. The Pearson correlation coefficient was used for statistical hypothesis testing, employing SPSS software version 19.
The results showed that according to the respondents’ viewpoints, scores of job satisfaction (Mean(SD):3.59±0.68) and patient safety culture (Mean(SD):54/0±31/3) Rasht city hospitals were at the average level. Furthermore, there was a significant direct relationship between nurses’ job satisfaction and patient safety culture with the correlation coefficient of 0.643 at the 0.01 level of significance.
According to the findings, it is necessary to improve study nurses’ job satisfaction and patient safety culture. Moreover, according to statistical correlation between research variables, increasing nurses’ job satisfaction results in improvement of patient safety culture.

Nowadays, exposure to extremely low frequency (ELF) magnetic field has been interested in many studies due to possible effects on human physical-mental health. Therefore, this study aimed to assess arc welders’ exposure to extremely low frequency magnetic field and to determine its relationship with the secretion of paratormone (PTH) hormone and mood states.
Material and The present study has been conducted among 35 healthy production workers (as exposed group) and 35 healthy administrative personnel (as unexposed group). After checking the work activities of participants according to the guide recommended by the National Institute for Occupational Safety and Health (NIOSH), ELF magnetic fields were measured using an ELF measurement device in the regions including trunk, head, and neck. The plasma levels of PTH hormone of both groups were evaluated by the Electrochemiluminescence method. Stress-Arousal Checklist (SACL) was used to assess the mode states of subjects in both groups. The collected data were analyzed by SPSS software version 16.
There was a significant difference between the exposed and unexposed groups with respect to the exposure level to ELF magnetic fields (P-value The results of this study showed that continuous welding can be considered as an exposure source to extremely low frequency electromagnetic fields. More accurate and comprehensive laboratory and field studies are needed to prove the hypothesis of the potential impact of extremely low frequency magnetic fields on people’s psychological states and mood through changes of parathyroid hormone level.