Aims: This study was conducted to determine the state of physical symptoms of the Iranian Central Iron Ore Company workers and its relation with history of work accidents. Materials and Methods: This cross-sectional descriptive study was performed at the Iranian Central Iron Ore Company and included 388 workers sampled randomly out of 2100 workers. Research tool was a two-part questionnaire that its reliability was determined by some of researchers. Data was analyzed by SPSS (Statistical Package for Social Science) software and statistical tests included variance analysis and Pearson' correlation tests. Results: According to the findings, 80.9% had favorable physical health conditions and there was a significant relationship between physical health condition, history of work accidents, cigarette smoking and type of work. Conclusion: Considering the strong relationship between physical health and history of work accidents, it is proposed that high-level managers of the Central Iron Ore Company of Iran should pay special attention to the improvement of physical health, psychological, social, and welfare levels.

Aims: The objective of this study was to evaluate the prevalence of Listeria spp. in the river water before and after discharge of the effluent of the municipal wastewater treatment plant (WWTP) in Isfahan, Iran. Materials and Methods: A total of 66 samples were collected bi-weekly over 4 months from eleven discrete sampling locations in Zayandehrood River, Iran. Three sampling sites were located above the discharge point and five sites were located after the discharge point of WWTP. Samples were also collected from the influent and the effluent of WWTP. Listeria spp. were isolated using a selective enrichment procedure and a subculture onto polymyxin-acriflavine-lithium chloride-ceftazidime-esculin-mannitol Agar. All isolates were subjected to standard biochemical tests. Results: L. monocytogenes was isolated from influent (83%), effluent (50%) and (18.5%) river water. Listeria spp. was not found before the discharge point in river water. However, L. monocytogenes was isolated in samples collected from 200 m (33%), 500 m (33%), 2 km (16.5%), 5 km (16.5%) and 10 km (16.5%) downstream from the WWTP. Listeria innocua (9%) and Listeria seeligeri (10%) were the second most frequently isolated species. Conclusion: During the wastewater treatment, Listeria spp. is not removed completely. L. monocytogenes is widely distributed in the Zayandehrood river. L. monocytogenes released into surface water demonstrates a potential risk for public health. These results indicate the need for appropriate water management in order to reduce human and animal exposure to such pathogens.

Aims: The objective of this study was to analyze major accidents take place in sour water refineries, and to assess the adequacy of safeguard layers in the system. Also it has been provided safety recommendations in regarding to our analysis. Materials and Methods: Using the layer of protection analysis (LOPA), the role of protective layers in controlling the potential risks in Sour Water Recycling Unit is determined and required recommendations to reduce risk are provided. Results: This study showed that there are 49 high risk areas in Sour Water Recycling Unit. Moreover, Excessive flow rate in pipelines, Excessive temperature, Reverse flow, H ₂ S leakage, Flow interruption, and Corrosion are the main identified hazards. Conclusion: It can be conclude that the effectiveness of protective layers is not enough and additional protective layers are required to improve the process safety system. Furthermore, LOPA is an improved technique when use the output of hazard and operability study (HAZOP) and it has some advantages due to its semi-quantitative nature in estimating hazards.

Aims: The purpose of this study was to isolate and identify aerobic polychlorinated biphenyls (PCBs) degrading bacteria. Materials and Methods: This study was performed in lab scale aerobic sequencing batch biofilm reactor. Polyurethane foams were used as bio-carrier and synthetic wastewater was prepared with PCBs in transformer oil as the main substrate (20-700 μg/l) and acetone as a solvent for PCBs as well as microelements. After achieving to adequate microbial population and acclimation of microorganisms to PCB compounds with high efficiency of PCB removal, identification of degrading microbial species was performed by 16s rRNA gene sequencing of isolated bacteria. Results: Gene sequencing results of the isolated bacteria showed that Rhodococcus spp., Pseudomonas spp., Pseudoxanthomonas spp., Agromyces spp., and Brevibacillus spp. were dominant PCB-degrading bacteria. Conclusion: PCB compounds can be degraded by some microorganisms under aerobic or anaerobic conditions or at least be reduced to low chlorinated congeners, despite their chemical stability and toxicity. Based on the results of the study, five bacterial species capable of degrading PCBs in transformer oil have been identified.

Aims: This study was carried out to determine nitrite and nitrate levels in fresh leek and spinach from different greengrocers' shops of Urmia (Iran) and then the effect of boiling and the effect of aqueous boiling pH were studied. Materials and Methods: Nitrite and nitrate content of 15 market samples of leek and spinach from Urmia region were determined by spectrophotometric method. Effect of boiling and their pH levels at home processing condition were studied. Results: Results showed that the fresh vegetables had only traces of nitrite and the level of nitrate was 36-328 ppm KNO ₃ . In the most of samples, nitrite and nitrate contents in spinach were greater than in leek, but lower than standard International Organization for Standardization levels in Iran. Boiling process was carried out, according to home conditions and it caused a decrease in nitrate levels between 23% and 61% in leak and spinach samples, respectively. T-test analysis of the boiled vegetables showed a significant reduction about 75% in nitrate content (in dry weight vegetable content), in the samples, but an increase in nitrate content in the boiled water of the sample was observed. The effect pH of boiling (4-8) shows that with an increase in pH, there was a decrease in nitrate contents of boiled water. Conclusion: The experiment showed that the leek and spinach marketed in Urmia region were safe for consumption and boiling of vegetables caused the release of nitrates from vegetables to water after the cooking process. It is of particular importance not to use the vegetable cooking water for use in pureeing homemade baby foods.

Aims: This study aimed to monitor the vibration levels of mining machinery and duration of exposure to vibration; to study work practices of operators of mining machineries and to predict health risk from vibration exposure to operators. Materials and Methods: Vibration levels of 157 mining equipment including dumpers, dozers, etc. in 10 opencast mines were measured through accelerometer and recorded in vibration analyzer. Root mean square (RMS) values of acceleration as well as vibration dose values along with duration of exposures per day were used to predict health risk in accordance with ISO 2631-1:1997 standard. Video records of equipment operation were used to analyze job components. Results: Health risk was evaluated using RMS acceleration (0.21-1.82 m/s ² ) and corresponding daily durations of exposure (2-7.5 h). Forty two (27%) of the equipment showed minimal health risk, 83 (53%) equipment showed moderate and 32 (20%) equipment showed high health risk to operators. While shovels and excavators showed minimal health risk, dozers and dumpers showed high health risk potential. x-axis was the dominant axis of vibration for loaders and dozers, whereas for the majority of dumpers and tippers, z-axis was dominant. Conclusion: Dumpers require engineering control for reducing the vibration in z-axis while measures are required for x-axis in loaders or dozers. Shovels or excavators do not require immediate attention except regular monitoring. Improvement in work practices are required to safeguard the workers from vibration related illness. It is recommended that proper guidelines for measurement and control of vibration at workplace should be formulated.

Aims: The aim of this study was to assess the effect of shift work on metabolic syndrome in Iran Polyacryl Corporation workers. Materials and Methods: This retrospective cohort study was conducted on Iran Polyacryl Corporation workers for 10 years. The incidence of metabolic syndrome was assessed between shift workers and day workers. For analysis of the effects of shift work on six different combinations of metabolic syndrome, Logistic regression was used, and information was analyzed with using Statistical Package for Social Science-SPSS version 18. Results: The mean triglyceride, body mass index, total cholesterol, and systolic blood pressure was higher in the day workers than rotating shift workers, but the difference was not significant (P value > 0.05). Logistic regression showed a significant inverse relationship between shift work and combination of three metabolic syndromes with a relative risk (RR) and %95 confidence interval (CI) of 0.24 and (0.06-0.94), respectively. Although shifts work increased risk of combination of numbers 2 (IFG, BP, and BMI) and 4 (IFG,TG, and BMI) metabolic syndrome 66% and 6%. These differences were not significant (RR = 1.66, %95 CI ; 0.81-3.37 and RR = 1.06, %95 CI ; 0.72-1.58 respectively). Other combinations of metabolic syndrome had a non-significant inverse relationship with shift work (P value > 0.05). Conclusion: Our findings indicate that rotating shift work not increases the risk of metabolic syndrome and different combinations. However, significantly decreased risk for developing combination 3 (Impaired fasting glucose, hypertension, and positive micro albuminuria).

Aims: This study aimed to evaluate the concentrations of toluene and ethylbenzene inside the Pride cars and to investigate the effects of the vehicle ventilation system, fule type, and interior smoking on their concentration. Materials and Methods: In the present study, 152 different models of Pride cars, stopped in parking [classified into three groups including: Pride KIA (Group I), Saba (Group II) 131, 141, 132, LX111, SX, and Nasim (Group III)] were sampled using activated carbon sorbent tube. The samples were analyzed using gas chromatograph-mass spectrometer. The vehicle ventilation, fuel type, and in-cabin smoking were recorded. Results: The average concentrations of toluene and ethylbenzene were 105.4 ± 270.5 and 19.09 ± 33.97 μg/m ³ , respectively. The average concentration of toluene was higher than that of ethylbenzene. The concentration differences of both toluene and ethylbenzen among the studied groups were not statistically significant. Conclusion: The ventilation condition, fuel type, and in-cabin smoking were not significantly impressive on the toluene and ethylbenzene concentrations inside the cars. However, simultaneous usage of the vehicle ventilation system and natural ventilation (windows) could lead to little decrease in toluene concentration levels inside the car, while smoking consumption by passengers can increase them.

Aims: The present study aimed to assess the occupational health problems of municipal solid waste management workers. Material and Methods: Cross-sectional descriptive study was conducted among solid waste management workers of Kerala, India. All workers (408) were included the study of which 313 (77%) participated. Data were collected by direct interview and clinical examination using a structured questionnaire. The observed morbidity like respiratory diseases, eye diseases, dermatological problems and nail infections were elicited by clinical examination. The point prevalence of other occupational related health events present either during the study time or during 1 month recall period and that occurred ever after entry in present occupation was collected by self-reported complaints and doctors diagnoses. Results: The mean age was 42.5 ± 7.2 years. The observed morbidity like respiratory diseases, eye diseases, dermatological problems, nail infections were high ranged from 21% to 47%. The reported prevalence of occupation related morbidities like falls (63.6%), accidents (22%), injuries (73.2%), and water-vector borne disease (7.1%) were high. The current prevalence of musculoskeletal morbidities showing that all major joints are involved (17-39%). Conclusions: The work related health-problems were reported to be high. The prevalence of Respiratory, dermatological, eye problems and injury, musculoskeletal problems were reported to be high among municipal solid work handlers. Measures are needed to improve the work environment of waste handlers by ensuring availability protective gears based on ergonomic principles, clean drinking water and washing and sanitation facilities during working hours.

Aims: In this study, the prevalence of antibiotic residues in pasteurized and sterilized commercial milk available in Shahre-kourd, Iran, was investigated. In addition, the influence of seasonal temperature changes on the prevalence of contamination was studied. Materials and Methods: Commercial milk samples of 187, including 154 pasteurized and 33 sterilized, milk samples were collected from the market between early January 2012 and late July of the same year. The presence of antibiotic residues was detected using the microbiological detection test kit, Eclipse 100, as a semi-quantitative method. Results: The results showed that 37 of the samples (19.8%) have contained antibiotic residues above the European Union Maximum Residues Limits (EU-MRLs), of which 28 samples (14.97%) were found to be contaminated but at the concentrations below the EU-MRLs. There was no significant difference between the contamination rate of pasteurized and Ultra High Temperature (UHT)-sterilized samples. Similarly, variation of weather temperature with seasons had no effect on the contamination prevalence of milk samples ( P > 0.05). Conclusion: Based on the result of this study, antibiotics residues were present in the majority of milk samples. Neither the season nor the type of thermal processing of the commercial milks had noticeable impact on the prevalence level of the milk samples. However, an increasing trend of prevalence level for antibiotic residues was observed with increasing the temperature through the warm season.

Aims : The objective of this study was investigation of the polycyclic aromatic hydrocarbons (PAHs) concentration in eight brands of black tea which is used more in Iran. Materials and Methods : In the present study, PAHs content of eight brands of black tea were extracted and analyzed with gas chromatography-mass spectrometry (GC-MS) equipped with Selected Ion Monitoring (SIM) technique. Results: The average of total PAHs compounds in analyzed teas was in the range of 139 to 2082 μg kg ^?−1 . PAHs with 5 to 6 rings were not found in the teas samples. Four rings PAHs compounds composed 46% of the total PAHs compounds and were the most dominant compounds. The same compounds were also dominant in tea bags. Conclusion: In the tea liquor, after brewing times of 10 and 120 minutes, the maximum and minimum releasing percentage of PAHs was observed, respectively. The result of this study confirmed the presence of PAHs in the tea leaves and tea liquor. Assuming that every person use 10 g of tea leaves every day and 10 minutes take for brewing time, the daily uptake of 16 PAHs will be 1.2 μg.

Aims: In this work, degradation of 4-chlorophenol (4-CP) was investigated in aqueous solutions using several oxidation systems involving ultraviolet/(UV)/H ₂ O ₂ , microwave (MW)/H ₂ O ₂ , and ultrasonic (US)/Fenton systems. Materials and Methods: Three pilot plant reactors consist of a photolytic reactor, a modified domestic MW, and an US bath reactor of 22 kHz frequency were constructed and separately used in batch mode. The effects of several operation parameters such as pH of the solution ranging 3-10, H ₂ O ₂ initial concentration ranging from 0.005 to 0.2 mol/l, and reaction time were examined. Concentration changes of 4-CP were determined using a spectrophotometer at an absorption wavelength of 500 nm. Results: The results show that the oxidation rate was influenced by many factors, such as the pH value, reaction times, and the amount of H ₂ O ₂ concentration. The optimum conditions obtained for the best degradation rate were pH = 7, H ₂ O ₂ concentration of about 0.05 mol/l and pH = 10, H ₂ O ₂ concentration of about 0.1 mol/l for UV/H ₂ O ₂ and MW/H ₂ O ₂ system, respectively. For US/Fenton system, the highest 4-CP degradation was achieved in pH = 3, H ₂ O ₂ concentration of about 0.05 mol/l in the percent of 0.025 mmol Fe/l. The highest 4-CP removal rate in optimum conditions of pH and concentration of H ₂ O ₂ , in UV/H ₂ O ₂ , MW/H ₂ O ₂ , and US/Fenton systems was >99% over the retention time of 40 min, 85% after 180 min, and >99% after 40 min, respectively. Conclusion: Based on the results of this study, the UV/H ₂ O ₂ and US/H ₂ O ₂ are successfully applicable for degradation of 4-CP in aqueous solution. Also, the kinetic study represented that the US/H ₂ O ₂ is capable of removing 4-CP slightly rather than UV/H ₂ O ₂ process.

Aims: This study investigated the annual and seasonal variation of turbidity; total dissolved solid (TDS), nitrate and nitrite in Parsabad water treatment plant (WTP), Iran. Materials and Methods: The water samples were obtained from the inlet and outlet of Parsabad WTP from February 2002 to June 2009. The samples' turbidity, TDS, nitrate, nitrite, pH, and temperature were measured according to standard methods once a month and the average of these parameters were calculated for each season of year. Results: The maximum concentration of inlet turbidity, TDS, nitrate and nitrite were 691, 700.5, 25, and 0.17 mg/l, respectively. These parameters for outlet samples in the study period were 3.0, 696.7, 18, and 0.06 mg/l, respectively. While these concentrations in outlet zone were lower than World Health Organization (WHO) or United States Environmental Protection Agency (US-EPA) water quality guidelines, WTP could not reduce the TDS, nitrate, nitrite and pH value and these parameters were not different in the inlet and outlet samples. However, the WTP reduced the turbidity significantly with an efficiency of up to 85%. Conclusion: This study showed that a common WTP with rapid sand filtration can treat a maximum river turbidity of 700 NTU in several years. As no differences were observed between inlet and outlet TDS, nitrate, nitrite and pH in the studied WTP. It can be concluded that compensatory schemes should be predicted for modification of these parameters when they exceed the standards in the emergency situations.

Aims: This study aimed to determine the concentration of heavy metals including lead (Pb), cadmium (Cd), and arsenic (As) in rice samples in Yazd markets. Materials and Methods: In this study, 108 rice samples were collected from 36 different brands including 26 imported and 10 Iranian rice varieties from July-December 2011. Determination of heavy metals was carried out by wet ashing and digestion methods following graphite furnace atomic absorption spectrometry and hydride generation atomic absorption spectrometry. Results: The average concentrations of lead in both Iranian and imported samples were 328.3 ± 81.44 and 254.55 ± 77.2 μg/kg, respectively, well above the safe limit set by Iranian standard, whereas mean concentrations of cadmium and arsenic were both below their permissible limit. In homemade rice samples, their concentration levels were shown to be 37.25 ± 23.39 and 33.5 ± 18.35 μg/kg, respectively. However, for imported products, their levels were 43.71 ± 13.74 and 87.55 ± 72.99 μg/kg, respectively. Conclusion: Deterministic estimation of exposure to heavy metals from rice showed that there was no health issue concerning exposure to toxic metals through rice intake in Iran when potential risk of each heavy metal is considered individually, cumulative risk assessment must be applied in future studies.

Aims: The aim of this study was to identify the sources of airborne contaminants in milk processing units. Materials and Methods: The aero-bacteriological investigation has been done fortnightly for a period of 1 year extramurally within the premises of milk processing unit complex with the help of modified two-stage Andersen Sampler. The raw milk samples were analyzed for total plate count and total coliform count. Results: The mean ± standard deviation of bioload of total coliform/mL, total plate count in million/mL, total airborne viable cultivable bacteria, Gram-negative bacteria, and the members of the family Enterobacteriaceae recorded were 3193.6 ± 220, 1673.33 ± 229.8, 3117.96 ± 1678.1, 46.33 ± 28.874, and 47.92 ± 33.5, respectively. Seasonal variations in airborne bacterial population were reported for this environment, high humidity and moderate temperature were the major factors for dissemination and distribution of Gram-negative bacilli. The temperature was positively and humidity was negatively significantly correlated with total airborne viable cultivable bacteria of this environment. There was no correlation established between bioload of milk and bioload of airborne bacteria. Conclusion: The airborne bacterial bioload in milk processing unit complex environment areas were higher than the acceptable limit, with temporal and spatial variations. Mechanical activities were supposed to be the key factor governing aerosolization of potentially harmful bacteria which could contaminate the products. These results could be useful to establish a standard to the small-scale dairy processing units where monitoring of airborne bacteria were rarely adopted by dairy manufacturers in their routine quality control.

Aims: The purpose of this study was to investigate the professional attraction rates on solid waste recovery area, current recovery market in the study area, and to determine their activity index. Materials and Methods: The recovery of materials in the active industrial units of Isfahan industrial parks, central area of Iran, were classified and analyzed. The quantitative and experimental studies were used. In each recovery area, employment, investment rate, and production capacity of industrial units were specified and the activity index was prescribed. Results: The highest activity index in the province relates to paper and metal with 17 and 16 units, respectively. In the study area, no study has been carried out about electronic waste and old cars recovery. Also employment in paper and metal recovery industrials are more than another with 385 and 221 persons per year, respectively. Conclusion: The recovery of solid waste and distribution of solid waste production in Isfahan showed that planning of solid waste recovery industry can be developed in future.

Aims: The objective of present study was to evaluate the new location of Isfahan solid waste sanitary landfill using Geographical Information System (GIS) based on the Oleckno index method (OIM). Materials and Methods: This study was on the field- and library-based data collection and surveys of relevant data. Assessment parameters included average annual rainfall, soil type and ground water beneath and adjucent to the landfill site. To analyze data, ArcGIS version 9.3 was used. Results: In 2010 the total rainfall in the landfill location was less than 150 mm/year. The soil type was clay loam, and the average distance from the floor of the landfill to the groundwater level was 3-9 meters. As calculated results showed that, the Oleckno index (OI) score in the study area was 40. Conclusion: The new Isfahan's sanitary solid waste landfill site had a good OI and the possibility of contamination of groundwater by leachate production based on this method also was low.

Aims: The aim of this study was to investigate the relationship between longitudinal change in total cholesterol as a main cardiovascular disease risk factor and shift work, controlling for the effect of the weight at baseline of recruitment. Materials and Methods: This retrospective cohort study consists of 674 employees of Iranian Corporation Polyacril from 1992 to 2009. Stratified analysis of the relationship between shift work and cholesterol based on weight status at baseline of recruitment controlled for the effect of confounders including age, body mass index, pre-employment cholesterol, glucose, triglyceride, urea, work types, education, and marital status. A linear mixed model used for analyzing the data. Estimation of parameters has done by Bayesian approaches using Winbugs statistical software. Bayesian confidence interval (CI) was used for testing regression coefficients. Results: Average age mean at employment was 25 years (standard deviation [SD] =3.3); the average number of measurement for each individual was 3.7 times (SD = 0.6). In this model, relationship between shift work and cholesterol changes controlled for confounding factors was significant in whom overweight was at baseline (beta = 2.25, P < 0.001, 95% CI: 0.67-3.88) but was not significant for whom overweight was at baseline of employment. Conclusions : The rate of cholesterol changes was higher for normal weight shift workers compared with workers who were overweight at baseline of recruitment.