International Journal of Environmental Health Engineering
Volume:2 Issue: 4, Jun 2013

 Traditionally, roadway safety analyses have used univariate distributions to model crash data for each level of severity separately. This paper uses the multivariate Poisson lognormal (MVPLN) models to estimate the expected crash frequency by two levels of severity and then compares those estimates with the univariate Poisson-lognormal (UVPLN) and the univariate Poisson (UVP) models. 

 The parameters estimation is done by Bayesian method for crash data at two levels of severity at the intersection of Isfahan city for 6 months. 

 The results showed that there was over-dispersion issue in data. The UVP model is not able to overcome this problem while the MVPLN model can account for over-dispersion. Also, the estimates of the extra Poisson variation parameters in the MVPLN model were smaller than the UVPLN model that causes improvement in the precision of the MNPLN model. Hence, the MVPLN model is better fitted to the data set. Also, results showed effect of the total Average annual daily traffic (AADT) on the property damage only crash was significant in the all of models but effect of the total left turn AADT on the injuries and fatalities crash was significant just in the UVP model. Hence, holding all other factors fixed more property damage only crashes were expected on more the total AADT. For example, under MVPLN model an increase of 1000 vehicles in (average) the total AADT was predicted to result in 31% more property damage only crash. 

 Hence, reduction of total AADT was predicted to be highly cost-effective, in terms of the crash cost reductions over the long run.

 This study was conducted to determine Benzene, Toluene, Ethylbenzene, and Xylene (BTEX) concentration regarding broken petroleum transmission pipeline in the east region of Isfahan, using passive sampling method. 

 Dialysis bags as passive sampling devices with molecular cut-off diameter of 12000 Dalton, 3.2 cm width and around 12 cm lengths were used that contain 2 ml of olive oil as an absorbent. These devices were placed, in 10 sampling wells for 45 days. In order to determine the absorption efficiency of these devices, laboratory calibration operations were performed at the same time. Nitrate as an indicator of contamination of groundwater with chemical fertilizers and also electrical conductivity (EC) as an indicator for cations and anions concentration was measured. 

 The laboratory absorption efficiencies of BTEX were found to be 90%, 85%, 79%, and 81%, respectively. Concentration of these compounds in field samples were less than 10 μg/l. Nitrate concentration varied between 2.1 to 69.2 mg/l, and EC varied between 1.7 to 15.1 mS/cm. 

BTEX compounds were absorbed with high efficiency in the laboratory test, but their concentrations in wells were found to be negligible. Average concentration of nitrate in the wells was less than water quality guidelines, and had no relation with the direction of movement or depth of water. EC tended to increase in the direction of groundwater movement, but there were no correlations among depth of water, nitrate concentration, and mean of EC.X

 The aim of this study was to determine the peroxide value, acid value and rancidity of edible oil which are used in sweet pancake, samosa, confectionery and sandwich shop. 

 This descriptive study was carried out on all sandwich shops and sweet pancake at north region of Isfahan city. The peroxide value, acid value and rancidity were determined based on national standard procedure number 4179, on thirty samples. 

 The average of peroxide and acid value was 5.2 and 0.5, respectively. Around 7.4 percent of tested oil has a non permissible rancidity value. Also, 87 percent of samples were healthy. In general, 98.1 percent of oil samples were unusable. 

 The acid and peroxide numbers was in acceptable range, however, the rancidity or oil chemicals corruption caused by inappropriate conservation conditions. This type of fast food, have adverse effects on consumers' health.

 The aim of present study was determination of occurrence of Listeria Listeria spp. in various point of a municipal wastewater treatment plant. 

 The samples were collected of influent, effluent, raw sludge, stabilized sludge and dried sludge from north wastewater treatment plant Isfahan, Iran. The presence of Listeria spp. was determined using USDA procedure and enumerated by a three-tube most probable number assay using Fraser enrichment broth. Then, biochemically identified Listeria monocytogenes was further confirmed by PCR amplification. 

 L. monocytogenes, L. innocua and L. seeligeri were isolated from 76.9%, 23.1% and 23.1% of influent, 38.5%, 46.2% and 7.7% of effluent, 84.6%, 69.2% and 46.2% of raw sludge, 69.2%, 76.9% and 0% of stabilized sludge and 46.2%, 7.7% and 0% of dried sludge samples, respectively. The efficiency of wastewater treatment processes, digester tank and drying bed in removal of L. monocytogenes were 69.6%, 64.7% and 73.4%, respectively. All phenotypically identified L. monocytogenes were further confirmed by PCR method. 

 Application of sewage sludge in agricultural farms as fertilizer may result in bacteria spreading in agriculture fields and contaminated foods with plant origin. This may cause a risk of spreading disease to human and animals. Using parameters such as BOD 5 is not sufficient standard for the elimination of pathogenic microorganisms.

 This study was done to evaluate the effect of three kinds of respiratory protective equipments (RPE) on the heart rate in light, moderate and heavy workload. 

 This study was performed on eleven healthy university students (male) under controlled thermal conditions in a climatic chamber. The mean (SD) of age, height and body mass index (BMI) were 24.1 (2.34) years, 172 (4.2) cm and 22.4 (1.1) Kg/m2, respectively. Subjects were participated in the four intermittent exercises experiments (without RPE, valve, half-face and full-face) on a treadmill in light, moderate and heavy workload. Duration of light, moderate and heavy activities was 30, 30 and 20 min, respectively. Heart rate was recorded every 5 min. 

 The mean of heart rate in 11 subjects for without RPE trial in light, moderate and high workload was 93.5±13.1, 109.7±18.1 and 119.6±25.8 beats per min (bpm), for valve RPE was 102.8±9.7, 116.7±16.0 and 132.1±23.2 bpm, for half-face RPE was 102.4±11.42, 117.3±15.8 and 132.0±23.1 bpm and for full-face RPE was 109.3±14.7, 125±17.4 and 140.1±23.1 bpm, respectively. In three work load, significant differences between the mean of heart rate by using three kinds of RPE trials showed with without RPE trial were observed (P-value < 0.001). Also, mean of heart rate in three workload levels when using full-face RPE trial was significantly higher than valve and half-face RPE trials. In the valve and half-face RPE trials, significant differences were not detected 

 The results demonstrated that heart rate were significantly increased with wearing of three kinds of RPE. Full-face RPE have a higher effect on increasing heart rate than half-face RPE.

 The objective of this study was to identify operators' error in distillation units of Isfahan oil refinery.

 Data were collected through task observation and interviewing with safety authorities, the unit and the shift supervisors and operators to identify and analyze critical tasks hierarchically (hierarchical task analysis). Then, human errors of each critical task were identified using systematic human error reduction prediction approach (SHERPA) technique. 

 Analysis of the SHERPA work sheets revealed 198 human errors of which 134 (67.64%), 23 (11.61%), 11 (5.6%), 24 (12.12%), and 6 (3.03%) were action, checking, communication, retrieval, and selection errors, respectively. Critical tasks of "performance monitoring" and "communication" were the main tasks of control room operators (C.R.O's). Low occurrence probability and medium occurrence probability were estimated 64% and 36%, respectively. Furthermore, 59% of the identified errors of C.R.O's had no required recovery of which only 29% had critical consequences. 

 The results showed SHERPA technique can be used as an effective technique to detect human errors in petrochemical and oil refineries.

 This study assesses the removal of fecal indicators (i.e., total coliforms, fecal coliforms) in a full-scale activated sludge and maturation pond system with primary screening facility that is operating in center of Iran. 

 A total of 54 grab samples for microbiological test were collected from the inlet and outlet of activated sludge (AS) and maturation pond (MP) during the winter and summer 2010 (3 sample per month in 3 locations). Collected samples were sent to laboratory and were analyzed for total coliformbacteria (TCB) and fecal coliform bacteria (FCB) according to Standard Methods. 

 The results of this study show that the maximum TCB removal in AS (92.2%) and MP (99.2%) were occurred in summer. Also, for FCB, the highest removal rate (99.7%) was recorded during the summer. The mean winter TCB numbers for AS and MP effluents were 2.7 × 10 7 and 2.3 × 10 6 (MPN per 100 ml), respectively. However, the effluent still contained a significant number of coliforms, which was greater than the permissible limit for unrestricted irrigation as prescribed by Iranian and WHO guidelines. 

 Removal efficiencies of fecal indicator bacteria were maximum during summer and minimum during winter. Statistical analysis indicated that TCB and FCB removal in MP is significantly affected by ambient temperature, whereas there was weak correlation between ambient temperature and coliform removal in AS system.

 This study was aimed to estimate the bisphenol A (BPA) intake from baby bottles, considering the diversity and the standard quality of the baby bottles distributed in an Isfahan urban society. 

 A cross-sectional study was performed in Isfahan in 2011. Baby shops ( n = 33) and drug stores ( n = 7) in four district areas were included in the study. The distribution of baby bottles was investigated regarding their brand, origin, and being labeled "BPA free." Estimation of exposure to BPA from baby bottles was made based on the national and international representative data. 

 The products marked as "BPA free" were found among the western products and limited to two of the selected areas. No "BPA free" marked baby bottle was distinguished among the Iranian made products. Of the 8% exclusively formula-fed infants, 90% may be the high consumers of BPA from polycarbonate baby bottles, with an intake of 1.5-2 μg/kg b.w./day for the moderate and 7.5-10 μg/kg b.w./day in case of worse condition. 

 Considering the current globally accepted threshold daily intake (TDI) for BPA, primary exposure estimation is that feeding using non-BPA-free baby bottles is not a serious health concern in Iran. Thought that threshold level of TDI is discussed to be reduced in future, improvement and revision of the national standards can be effective in reducing the exposure to BPA in Iranian infants so as to provide large margin of safety for them.

Changes in regulations and development of new technologies have affected the selection of alternative for treated wastewater disinfection. Disinfection is the last barrier of wastewater reclamation process to protect ecosystem safety and human health. Driving forces include water scarcity and drinking water supply, irrigation, rapid industrialization, using reclaimed water, source protection, overpopulation, and environmental protection. The safe operation of water reuse depends on effluent disinfection. Understanding the differences in inactivation mechanisms is critical to identify rate-limiting steps involved in the inactivation process as well as to develop more effective disinfection strategies. Disinfection byproducts discharged from wastewater treatment plants may impair aquatic ecosystems and downstream drinking-water quality. Numerous inorganic and organic micropollutants can undergo reactions with disinfectants. Therefore, to mitigate the adverse effects and also to enhance that efficiency, the use of alternative oxidation/disinfection systems should be evaluated as possible alternative to chlorine. This review gives a summary of the traditional, innovative, and combined disinfection alternatives and also disinfection byproducts for effluent of municipal wastewater treatment plants.

 The purpose of this study was to determine the types of fungal contamination and evaluation the fecal Streptococcus, total coliform and some physical and chemical parameters of swimming pool waters in Hamadan (Iran).

 In this study, biological and physico-chemical quality were evaluated. Bacterial and fungal contamination of four public indoor swimming pools was evaluated by standard total coliforms fermentation and using membrane filtration and carpet and swab sampling method with a month interval. In addition, physical and chemical parameters such as residual chlorine, temperature and pH were measured. 

 Results showed that the mean water temperature pH and residual chlorine were 29.3±1.3, 7.38±0.5 and 0.84±0.5 mg/L, respectively. Mean of total coliform was 1.8±7.7 MPN/100ml and its maximum and minimum were 43 and 0 MPN/100ml, respectively. Mean of fecal streptococcus was 0.3±1.6 MPN/100ml and its maximum and minimum were 9 and 9 MPN/100ml, respectively. In the environment of pools, fungi were isolated in order of Cladosporium spp., Penicillium spp., Aspergillus spp., Alternaria spp., Aspergillus.niger spp., Rhodotorula spp and Phoma spp. In the collected water sample, no fungal growths were seen. In the studied pools, the microbial and fungi contamination showed significant and insignificant difference, respectively. 

 As results showed the residual chlorine in pools water was lower than standard level and as regard to microbial contamination in pool water, it can be concluded that the disinfection system has been impaired.