نشریه طب کار
سال هشتم شماره 2 (پیاپی 23، تابستان 1395)

A hospital as a health care institution providing treatment services can be heavily influenced by sources of noise. Noise pollution has negative impacts on patient comfort and staff welfare. This study aimed to evaluate the relationship between noise annoyance and sensitivity with noise parameters (PNC, SIL) in the hospitals of Behbahan.
This study investigated the level of noise pollution in all sections of Behbahan hospitals durring three working shifts. Noise measurement was done according to ISO9612 at designated stations. Equivalent sound pressure levels were measured at the measuring stations in 30 minute intervals. In the next step, PNC and SIL Indices were calculated. At the same time the validated questionnaire was completed for the evaluation of noise annoyance among 158 workers .Finally the relationship between the noise level, noise annoyance, noise Sensitivity, and PNC-SIL Indices.
The results showed that there was a significant relationship between noise sensitivity and noise annoyance (P˂0.001). Also statistical tests showed that there was a significant relationship between noise sensitivity, noise annoyance with equivalent sound level (P= 0.05). Moreover, SIL-PNC had a significant relationship with noise annoyance and sensitivity.
Based on the results, the noise level in some hospitals was higher than the national standard in Iran. PNC&SIL rating indicated that communication can be difficult for individuals; therefore, this problem causes raising the voice and consequently noise annoyance on of hospital staff.

Firefighters are exposed to different chemical and physical hazards and experience a significant number of accidents and injuries. Therefore, they are known as a high-risk group for post-traumatic stress disorder (PTSD). The aim of this study was to determine the prevalence of post-traumatic stress disorder among firefighters in Isfahan city.
Subjects were 261 male firefighters of Isfahan city (mean age: 37.5±6.98 years). In this study, three standard self-report scales including Post trauma Symptoms Scale (PTSS-10), Impact of Event Scale (IES-15) and DSM-IV criteria were used. The data were analyzed by SPSS (ver. 20) using Pearson’s correlation test, chi-square test, t-test and Cronbach’s alpha coefficient.
The mean (± SD) score of Impact of Event Scale, Post trauma Symptoms Scale and DSM-IV was criteria 32.86 ± 14.46, 3.3 ± 3.18 and 6.8 ± 4.0, respectively. Cronbach's alpha coefficient for the three scales of DSM-IV, Impact of Event Scale and Post trauma Symptoms Scale was 0.83, 0.843 and 0.916, respectively. Results showed that mean scores of IES had a significant relationship with age (P=0.001) and work experience (P=0.001). Also a mean score of PTSS had a significant relationship with age (P=0.03) and work experience (P=0.01).
IES-15, PTSS-10 and DSM-IV can be useful tools to assess the prevalence of PTSD and the Persian version of these scales was valid and reliable. Based on the results, the probability of PTSD among firefighters was high, that can negatively affect on their habits, attitudes, interests and lifestyles. Therefore, it is necessary to take preventive and treatment measures of PTSD should be proposed and implemented.

obstructive sleep apnea is a common disease that is recognized as the leading cause of occupational injuries and accidents. Proper assessment and treatment of employees affected by this disease can reduce the numerous side effects if the methods used to identify and treat these patients are evidence based and are applicable in our country.
In order to standardize the clinical services provided to patients, after studying the available guidelines, according to the conditions and possibilities of our country, the clinical guideline for Manual titration of CPAP and BPAP in patients with obstructive sleep apnea was provided.
This guideline contains recommendations for the diagnosis of patients with obstructive sleep apnea, recommendations for CPAP and BPAP titration studies, and acceptable PAP titration study. The level of evidence is specified for each recommendation. “Standard” is a generally accepted strategy and reflects a high degree of clinical certainty, “guideline” reflects a moderate degree of clinical certainty, “option” has less evidence and agreement was reached in a standardized consensus. Those recommendations that were not based on published parameters are labeled as “consensus”.
Considering that the most important problem for the use of CPAP is patient intolerance, a standard protocol for titration increases the patient compliance and treatment efficacy.

Diagnosis of various diseases in medicine is one of the area's most widely used data mining in recent years and many researches have been done about it. In this study, the diagnosis of prostate cancer using fuzzy system was assessed. The goal was to diagnose the prostate cancer and to predict the possibility of suffering from the disease.
In the proposed method, at first, based on available dataset, pre-processing and clustering operations were carried out. Then a zero-order Sugeno fuzzy system was designed for prediction. Each cluster, as the first item of a fuzzy rule, was considered and out of a rule, percentage of disease possibility in each cluster was considered. For each new sample, the membership degree to the each cluster was computed and then by combining outputs from each rule, possibility of disease in the sample was predicted. Finally, by having possibility and threshold for possibility, having or not having the disease for desired sample was diagnosed.
The results showed that the system has good accuracy in predicting the possibility of disease.
The results of this study can be used to predict the risk of prostate cancer in young workers according to different jobs they are employed and the amount of exposure to risk factors in each job. If this possibility is high, they are known as the person at risk and in some cases there may need to change higher jobs.

Diagnosis of various diseases in medicine is one of the area's most widely used data mining in recent years and many researches have been done about it. In this study, the diagnosis of prostate cancer using fuzzy system was assessed. The goal was to diagnose the prostate cancer and to predict the possibility of suffering from the disease.
In the proposed method, at first, based on available dataset, pre-processing and clustering operations were carried out. Then a zero-order Sugeno fuzzy system was designed for prediction. Each cluster, as the first item of a fuzzy rule, was considered and out of a rule, percentage of disease possibility in each cluster was considered. For each new sample, the membership degree to the each cluster was computed and then by combining outputs from each rule, possibility of disease in the sample was predicted. Finally, by having possibility and threshold for possibility, having or not having the disease for desired sample was diagnosed.
The results showed that the system has good accuracy in predicting the possibility of disease.
The results of this study can be used to predict the risk of prostate cancer in young workers according to different jobs they are employed and the amount of exposure to risk factors in each job. If this possibility is high, they are known as the person at risk and in some cases there may need to change higher jobs.

Based on the results of some studies, concurrent exposure to organic solvents and noise in industrial areas can accelerate the amount of hearing loss. The aim of this study was to assess the effect of concurrent exposure to organic solvents and noise on high frequency hearing loss.
This was a cross-sectional analytic study conducted on 1029 tire manufacturing company workers in 2013. After coordination with the factory authorities, required data including demographic, occupational and medical data and also audiometric records were derived from workers medical profile. Finally all gathered data were analyzed using SPSS version 13 software.
After applying inclusion and exclusion criteria, 914 workers entered the study. The results of this study showed that, the workers including group 4 (workers exposed to impermissible levels of noise and organic solvents) had more severe high frequency hearing loss in comparison to group 1 (workers with no exposure to impermissible levels of noise and organic solvents) (OR= 1.74, 95% CI: 1.15-2.63) and the hearing loss was significant even after modification by logistic regression analysis.
Our study showed that the workers exposed to impermissible levels of noise and organic solvents had higher levels of high frequency hearing loss in comparison to workers with no exposure to impermissible levels of noise and organic solvents, thus we propose that workers with co-exposure to impermissible levels of organic solvents and noise may be benefited from shortening the interval between periodic audiometric evaluation.

Fatigue and sleepiness can negatively affect driver’s consciousness and their cognitive function. Traffic accidents due to sleepiness are more common among people who work more than 60 hours a week, or have irregular working hours or night shifts.
Last available literature and the most authentic sources were assessed and different aspects of the issue were evaluated.
Drowsy driving increases the risk of a crash four times. Fatigue reduces performance in tasks that require alertness, manipulation and retrieval of stored information. There are several instruments to measure drivers’ sleepiness including Multiple Sleep Latency Test, Maintenance of Wakefulness Test, Epworth Sleepiness Scale, Karolinska Sleepiness Scale, and Stanford Sleepiness Scale.
Careful consideration and scientific approach to professional drivers’ work schedule to prevent sleepiness, fatigue, and driving for long and consecutive hours and also the study of underlying sleep diseases, are highly important.