Iranian Journal of

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Backgrounds and Objectives: Noise in large cities is considered by the World Health Organization to be the third most hazardous type of pollution. Buses are an interesting object of study in the theme of noise pollution. They are at the same time a source of urban environmental (traffic) noise and occupational noise exposure source for drivers. The object of this study is Occupational noise exposure evaluation in drivers of bus transportation of Tehran city.
Materials and Methods: Noise levels in 90 buses were sampled in three separate sub-sample including (1)30 Ikaroos buses (2)30 Man buses (3)30 Shahab buses, which were selected by simple random sampling. Noise exposure level was normalized to a nominal 8-h working day (LEX, 8h). Simultaneous Octave Frequency Analysis were measured and sound intensity level (SIL) for bus drivers were calculated. Results, which are obtained from separate buses were compared together and too with standard levels.
Results: the normalized noise exposure levels (LEX, 8h) in Ikaroos bus drivers(82dB A) were higher than that of in in Man bus drivers (77/6dB A) and this Values were higher than that of in Shahab bus drivers(75dB A).SIL values for Ikaroos bus drivers were higher than other that of other bus drivers. Results obtained of Frequency Analysis showed that age of buses in mid frequencies ws a meaningful on noise increase.
Conclusion: Results showed that type and age of buses were effective factors in drivers. noise exposure levels (LEX, 8h), which was consistent with previous studies in this field.

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Background and Objectives: Not paying attention to management and control of medical wastes in different stages of production, keeping, gathering, transporting and finally eliminating them all have been creating various setbacks such that the environment and human's health are in danger with the relevant consequences. This descriptive cross-sectional study was performed in Vali-e Asr, Amir Kabir, Taleghani, Amir Al-Momenin and Imam Khomeini hospitals of Arak city in 2009. In this research the current condition of gathering, maintaining, transportation and final elimination of hospital wastes of Arak city was investigated .Eventually an appropriate model was introduced.
Material and Methods: Solid wastes were separated, weighed and registered in two sequential intervals. In order to get acquaintance with the management procedure of medical solid wastes in the hospitals studied, a questionnaire approved byW.H.O was used. The questions were then replied by the Managers and Hygiene Experts worked at hospitals and their responses were recorded.
Results: The investigations conducted in 5 hospitals reveal that the average per annual was2.9 Kg in 24 hours per active bed and 4.6 Kg for each patient. This volume consists of 60% for semi-home solid wastes, 39% for infectious solid wastes, 0.34% for sharp wastes, 0.28% for the pathologic and 0.38% for medicinal and chemical solid wastes.
Conclusion: According to the results obtained in this study, in order to reduce pollution create in the hospitals, action should be taken to deal with pollutants at their source of generation. The staff members involved in waste collection and transportation should practice all the personal protection measures.finaly it also should be considered that,success in medical waste management wouldn't be achievable unless all groups of medical staff involved cooperate and participle.

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Background and Objectives: with the developments of technology, contact with various frequencies of electromagnetic fields ( EMF ) has significantly increased, while the abundant benefits of using microwaves in routine life cannot be neglected. During recent years there have been reports of adverse effects caused by contact with electric and magnetic fields of these waves that spread from BTS antennas. The purpose of this study is the measurement of microwaves spreading around BTS antennas in Tehran.
Materials and Methods:  according to the location of BTS antennas in Tehran , power density of electromagnetic waves around 63 antennas in near and distant fields in different distances was measured. The measurements were performed using the standard method of IEEE Std C95.1 by Hi-4333 device .in order to analysis  data we used spss 16 and descriptive and deductive statistical tests.
Results: results of this study show that in the near field, with increase of distance  from the foot of antenna , the  average power density of electromagnetic waves increase in a way that in the distance of 10 meters from the antenna foot , the increase of average power density is hardly conceivable and from 10 to 15 meters distance is perfectly noticeable. But in the distant field, with increase of distance from 20 meters, the average power density of the electromagnetic waves decreases and from 100 meter and further, the gradient of the diagram will get almost linear and the rate of power density reaches the base limit in a way that with the increase of distance there would be no significant decrease.
Conclusion: All the measures of power density of electromagnetic waves caused by BTSs are about 0.06% of recommended measures of environmental standards and 0.0000013% of occupational standards. The results of this study are close to the results of other studies.

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Background and Objectives: The heavy metals pollution in aquatic ecosystems especially mercury, always makes concern about health of aquatic organisms. So, the purposes of this study were determination of total mercury in different tissues of the three species of the most important water birds at north of Iran and comparison with world health standards.
Materials and Methods: Generally, 51 birds were captured randomly. Then, samples of feather, liver, kidney and muscle were taken and the mercury concentrations were determined by Advanced Mercury Analyzer (Model Leco, AMA 254).
Results: The most amount of accumulated mercury was in great cormorant's liver (piscivorous species). Means of mercury concentration in liver of great cormorant, mallard, and coot were 14.80, 2.05, 0.18 in kidney 12.00, 1.90, 0.17 in feather 6.57, 1.09, 0.23 and in muscle 8.67, 0.26, 0.09 mg/kg dry weight respectively. Means Comparison showed significant difference among all tissues (P < 0.05), But there were not significant difference between sexes (P > 0.05)
Conclusion: The levels of accumulated mercury in all tissues of great cormorant were more than the established limits by WHO, FAO and EPA. The other species had less use limitation, but mercury concentration in mallards was considerable. These results can be a serious warning for consumers these birds, especially vulnerable people.

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Background and Objectives: Sound of motorcycles plays an important role in noise pollution in big cities. This is due to the lack of national law or standards to control the noise of domestic and also imported motorcycles. This study tries to introduce a practical limit value in different stage of motorcycle life cycle by assessing their noise pollution.
Materials and Methods: First the motorcycles noise standards at different countries were studied and they were compared with the results from noise level of 622 motorcycles in 3 different groups. The sample volume in each group corresponds to the amount of their annual production rate. Then using statistical tests, a limit was determined in which 90% of the domestic motorcycles can be covered. The limit is proposed as the standard for domestic motorcycle noise.
Results: The limit for motorcycles of groups 1, 2 and 3were 84, 86 and 87 dB (A) ,respectively in the TA stage. For the COP stage (Conformity of Production), the limit increases according to certain formula. In the end, a flowchart was proposed as a standard method for measuring the sound of motorcycles in the TA and COP stages was proposed.
Conclusion: Noise level of the domestic motorcycles is at least 9 dB (A) higher than the noise limit value of European motorcycle. If European limit value is considered for producing the national motorcycle, 90% of them will get out of production cycle and this would not be practical.

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MicrosoftInternetExplorer4 Background and Objectives: Heat stress is considered as a serious threat to the health and safety of workers in many industries, including petrochemical and steel. Assessment of the heat stress is important from the disease prevention point of view and also for the safety and performance of workers at workplace. Although there are many indices to evaluate the heat stress, it is hard to select an applicable index for a wide range of weather conditions. The purpose of the study was to develop an optimal index based on physiological parameters in a petrochemical industry. 
Materials and Methods: The study was conducted in a petrochemical industry located in Assaluyeh (south of Iran). Twenty one healthy young men at different levels of fitness and heat acclimation volunteered to participate in the study. Physiological parameters including heart rate, systolic and diastolic blood pressure, skin temperature and oral temperature were measured during the working day over two consecutive weeks. Simultaneously, we measured the climatic parameters required to calculate the wet bulb globe temperature (WBGT), required sweat rate (SWreq), and the discomfort index (DI) indices.
Results: All the measurements took place on 2 sites: Kar (working place) and Paziresh (resting room). Our results showed  that the mean values of indices and physiological parameters   in Kar    for both acclimated and unacclimated groups were significantly higher than Paziresh (P<0.05). There was the strongest linear correlation between WBGT and heart rate (0.731), systolic blood pressure (0.695) and diastolic blood pressure (0.375) and skin temperature (0.451) respectively. The amounts of DI were 0.725, 0.446, 0.352, and 0.689 respectively. But the strongest linear relationship existed between SWreq and deep body temperature (0.766).
Conclusion:  There were significant differences in the present indices and physiological parameters of Kar and Paziresh, confirming the previous studies findings. Finally, WBGT was considered optimal index and the results revealed the almost perfect linear correlation between WBGT and heart rate. We propose WBGT can be the most applicable index for evaluating heat stress in this climate.  

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Background and objectives: In this research, an innovative drinking water quality index for assessing water resources as “modified drinking water quality index (MDWQI)” was developed and applied for evaluating all of the groundwater resources utilized for community water supply in urban areas of Iran during 2011. Materials and methods: Twenty-three water quality parameters and relevant Iranian standards for drinking water quality were selected as input parameters and benchmarks respectively. The MDWQI is calculated using three factors including the number of parameters that excurse benchmarks, the number of measurements in a dataset that excurse benchmarks and the magnitude of excursions. The MDWQI scores range from 0 to 100 and classify water quality in five categories as excellent (95-100), good (80-94), fair (65-79), marginal (45-64), and poor (0-44). Results: According to the MDWQI value, about 95% of the groundwater resources were in the good condition and the others were in the fair or marginal condition also the best and the worst water quality of water resources were observed in Ardebil Province and Qom Province respectively. The three parameters of fluoride, magnesium, and nitrate recorded the highest rates of violation to be 74, 32, and 13% respectively. Conclusion: The nationwide average score of the MDWQI was 85 (good description). This study indicated that the MDWQI and its sub-indices could describe the overall water quality of water bodies easily, reliably and correctly and have the potential suitability for extensive application all over the world.

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Background and Objectives: PAHs are main components of urban air pollution and are mutagenic for human being. Seasonal variations have effects on the amount of exposure to PAHs. The objectives of this research were to determine the amount of newsagent’s exposure to PAHs found in the urban atmosphere of Tehran City during warm and cold periods and comparing exposure levels in two periods. Materials and Methods: The assessment of personal exposure was performed based on NIOSH method 5515 and was analyzed by gas chromatography–mass spectrometry (GC/MS). Mann- Whitney test was used to determine the effects of seasonal variation on the amount of newsagent’s exposure to PAHs. Results: The mean levels of newsagent’s exposure to benzo[a]pyrene in the south area of Tehran City were 0.148±0.010 and 0.417±0.041 µg/m³ in summer and autumn seasons respectively. The amount was higher than the mean levels of newsagent’s exposure in other geographic areas of city. The levels of newsagent’s exposure to all PAHs (p<0.001) were significantly higher in autumn compared with summer. Conclusion: The levels of exposure to PAHs during autumn were 2 to 3 fold higher than the levels of exposure during summer. Newsagents in the south area of Tehran City were experiencing higher levels of exposures to PAHs.

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