Jundishapur Journal of Health Sciences
Volume:10 Issue: 2, Apr 2018

Cadmium accumulation is a growing problem for foodstuff and the environment; it has negative impacts on humans including the damage to kidneys and liver tissue, as well as carcinogenesis, and emphysema.
The current research aimed at evaluating the effect of planting systems of agricultural products and different growth stages on cadmium concentration in wheat seed.
The study was carried out as a split plot experiment based a randomized complete-block design with 3 replications in the seasonal year of 2014 - 2015. The main factor included 2 cropping systems (wheat-rice, fallow-wheat) and the subfactor were the growth stages (tillering, flowering, and maturity). Comparison of the amount of wheat seed cadmium concentrations between the 2 cropping systems was performed by t test.
The difference in seed cadmium concentration between the 2 cropping systems was significant (P Due to high accumulation of cadmium in wheat yield, management of phosphate consumption based the standards of Soil and Water Research Institute is recommended.

Nitrogen is a potential pollutant of water resources. They penetrate in water resources through insufficiently treated wastewater that is rich in nitrogen. The present study aimed at evaluating the efficiency of an anoxic/aerobic cycling reactor (AACR) with continuous flow in removing nitrogen and organic matter from wastewater.
Experiments were performed using a reactor with continuous intermittent influent and effluent. In this reactor, 4 phases with aeration and mixing cycles were designed and efficiency of each phase in removing nitrogen compounds was evaluated at 600 mg/L chemical oxygen demand (COD) concentration, 40 mg/L ammonia concentration, and 18- to 30-hour hydraulic retention times (HRT).
Results demonstrated that all cycles had great performance in removal of COD. Average COD removal efficiencies in phases 1, 2, 3, and 4 were 93%, 96.3%, 96%, and 94%, respectively. In phase 2, removal efficiency of 98.7% was obtained at hydraulic retention time of 24 hours, COD concentration of 600 mg/L, and ammonia concentration of 40 mg/L.
Phase 2 showed great efficiency in removal of nitrogen compounds. Combination of anoxic aeration stages and short cycles in anoxic/aerobic cycling reactor resulted in great performance of this reactor in removing nitrogen from wastewater. As a result, continuous influent and effluent flow, and not needing external carbon resulted in AACR good performance in removing nitrogen compounds and organic materials.

The measurement of physical work capacity (PWC) is important to create the physiological balance between work and worker. The results of some studies showed a relationship between maximum amount of oxygen consumption (VO2-max) and FEV1 (forced expiratory volume in the first second). The current study aimed at determining the relationship between PWC and asthma disease.
The current cross sectional study was conducted on 44 workers with different degrees of asthma disease (mild, moderate, and severe) and 44 workers without asthma. At first, the information about age, height, weight, smoking, doing exercise, and heart disease was collected by a questionnaire. The heart rate of the subjects was measured after resting for 15 minutes. Then, Tuxworth and amp; Shahnavaz method was employed as the step test method to measure the PWC. In this method, the subject went up and down a 40-cm height stair at a rate of 25 steps per minute for 5 minutes, then the subject sat down and after 30 seconds his heart rate was measured in the following intervals: 30 to 60, 90 to 120, and 150 to 180 seconds. Finally, data were analyzed with the SPSS version 16, using independent t test and analysis of covariance (ANCOVA).
The mean PWC index was 5.18 kcal/minute in subjects with asthma and 4.79 kcal/minute in subjects without asthma. The mean and standard deviation (SD) of PWC were 5.15 (0.29) kcal/minute in the subjects with mild asthma, 4.87 (0.60) in subjects with moderate asthma, and 4.28 (0.34) in the ones with severe asthma, respectively. The results showed that the mean PWC in the 2 groups with and without asthma were significantly different (P Based on the study results, PWC was correlated with different degrees of asthma, and asthma disease was an important factor impressing PWC.

Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating, and neurodegenerative autoimmune disease of the central nervous system (CNS). In the disease, the immune system attacks myelin sheath around neurons. The pathogenesis of this disease is still unknown, but there is evidence of complex interactions of both environmental and genetic factors. The recent evidence suggests that HLA class I may also contribute to MS and the negative association and protective role of HLA-A*02 with MS is confirmed. The current study aimed at investigating the association between HLA-A*02 with MS in Khuzestan province, Iran.
The current study was conducted on 200 patients with MS and 200 healthy controls from Khuzestan Province. The male to female ratio was 1:4. HLA typing was performed by polymerase chain reaction (PCR) amplification with sequence-specific primers (PCR-SSP) method. The association between HLA-A*02 and MS was evaluated with SPSS version 21 using chi-square test.
The most abundant type of MS in the current study participants was RRMS with the frequency of 87.93%, and the remaining 20% had progressive relapsing (PR), primary progressive (PP), and secondary progressive (SP) MS. There was a significant decrease in the frequency of HLA-A*02 in patients with MS (29%) in comparison with the healthy control (54%) and negative association of HLA-A*02 with MS (P According to the current study results, HLA–A*02 genotype decreased the risk of MS and had a protective role against multiple sclerosis in Khuzestan Province.

If shutdown scenario of burner of the sulfur recovery unit takes place, toxic release, fire, and explosion accident can easily occur. Therefore, it is essential to assess the basic causes of burner shutdown scenario. Fault Tree Analysis (FTA) could be used to assess the occurrence probabilities of burner shutdown scenario and its basic causes/events. The failure occurrence probability of these Basic Events (BE) are often not available in lack of data and uncertain conditions.
This study was done to provide a comprehensive approach for analyzing and calculating BE failure occurrence probability affecting the shutdown scenario, using combined fuzzy logic, expert judgment, and FTA.
The study was carried out from June to December, 2016. In this study, a fuzzy-based approach based on expert judgment was proposed to calculate the occurrence probability of burner shutdown scenario in lack of data and uncertain conditions. The brainstorming and FMEA, and HAZOP study were first used to identify fault events of the fault tree. Then, based on these methods, the fault tree was constructed. Subsequently, the failure occurrence probabilities of BE and shutdown scenario were calculated using the fuzzy-based approach and a conventional approach. Finally, the Fussell-Vesely importance analysis was used to rank the BE in FTA.
Results showed that the occurrence probability of shutdown scenario was 4.76E-04 per year. Since the failure occurrence probabilities of some BEs were not available, using failure probability functions in the conventional approach cannot provide failure occurrence probabilities of those BE. Therefore, the occurrence probability of shutdown scenario based on the conventional approach was not available. Based on the Fussell-Vesely importance measure analysis, it was determined that the blower failure while running, air pre-heater blockage, and shut-off valve fail close were 3 major causes of “burner shutdown scenario”.
The fuzzy-based approach could derive a failure occurrence probability of BE based on expert subjective judgments using the failure possibility distributions (FPDs) in lack of data conditions. This study overcame the weaknesses of the conventional approach, to calculate BE failure occurrence probabilities via fuzzy logic.

Overhead crane operators work long hours in a confined space and often face ergonomic and physical risk factors. The main purpose of this study was to find a better understanding of the risk of MSDs in overhead crane operators.
This study was conducted in a steel industry. The Nordic musculoskeletal questionnaire (NMQ) was used to determine the prevalence of musculoskeletal disorders in overhead traveling crane operators. Moreover, the exposure level to musculoskeletal disorders in 2 crane models (A and B) was investigated using QEC (quick exposure check) method.
Final results obtained from the NMQ revealed a high prevalence of musculoskeletal disorders in overhead crane operators, especially affecting the waist (83%) and the neck (71%). Moreover, final results obtained from posture evaluation indicated a significant difference between postures of the crane operators for the models of A and B. Level of exposure to the risk factors for the back was moderate and average for the A and B model cranes, respectively. However, the exposure level to the risk factors for the neck was high in both models, with the B model (score of 14), causing a higher level of exposure to risk factors compared with the A model (score of 12). Subjective perception of whole body vibration was at an average level, and the range of the operators work stress was found to be high.
Results of the study indicated that the prevalence of back and neck pain among the operators was high. Moreover, the main risk factors that were probable causes of this high level of prevalence were awkward posture and vibrations in the cabins.

Triethylene glycol (TEG) is an organic compound of the two-factor or di-alcohol alcohols and is used as a vinyl plasticizer. TEG has high toxicity and is classified in the chemical and polymer production group of petrochemical industry.
The current experimental study was conducted on a pilot scale. The total volume of the pilot study was 35.1 liters and its useful volume considering freeboard was 30 liters. The range of variables in the current study was input COD (chemical oxygen demand) (1000 - 3000 mg/L), pH (6, 7, and 8), C6H14O4 (600, 800, 1200, and 1800 mg/L), and hydraulic retention time (6, 8, 10, and 10 hours).
The results of the study showed that by increasing the compatibility time within 30 days, the COD input to the system also increased, as the input organic loading of the system in the 10 days was 769 mg/L, and then this amount after 20 days, the time spent for 30 days was 941 mg/L, during which high concentrations of sewage could be significant. On the other hand, output organic loading also increased with the overtime and increase of the input organic loading. By increasing the moving bed biofilm reactor (MBBR) hydraulic retention time after 5 hours, residual COD level of input to the amount of 1165.2 mg/L reached 40.5 mg/L.
The obtained results showed that the MBBR system had the highest efficiency after 5 hours and optimized pH 8 for concentrations of TEG entering the system about 600 and 800 mg/L were 96.5% and 92.87%, respectively; and in the hydraulic time of 1 hour reached the efficiency of about 70% at 600 mg/L concentration, and no removal was observed in 800 mg/L, which can be concluded that in 1 hour or less and at concentrations of 800 mg/L and above, it can be used as pretreatment.

The quality of groundwater as the most important source for domestic, irrigation, and industrial purposes is affected by discharge of the chemicals from the anthropogenic resources. Therefore, the current study aimed at predicting heavy metals (As, Pb, Cu, and Zn) contamination in groundwater resources of Toyserkan Plain as an important agricultural area in Hamedan Province, West of Iran using artificial neural network - particle swarm optimization (ANN- PSO) approach.
In the current study, samples were randomly selected from 20 groundwater wells with depth of 10 - 90 m. The samples were filtered and kept cool in polyethylene bottles and then taken for the analysis of metal contents; they were acidified using nitric acid to reach pH The results showed that among the analyzed groundwater samples, the detected amounts of As ranged 0.08 to 7.48 µg/L, Zn 0.12 to 15.64 µg/L, Pb 0.09 to 5.50 µg/L, and Cu 0.89 to 13.58 µg/L. Also, based on the results, the potential of ANN-PSO model to predict the concentration of heavy metals in the Toyserkan Plain was useful to implement sustainable policies for groundwater management.
The proposed method can be effectively applied to predict the concentration of heavy metals in groundwater resources of Toyserkan Plain.