مجله سلامت و بهداشت
سال دهم شماره 2 (پیاپی 41، تابستان 1398)

Because of human exposure to various environmental risk factors during the lifetime, the actual exposure estimation has been considered as one of the most important challenges for researchers and decision makers. Considering the contribution of environmental risk factors in the burden of diseases, this study aimed to provide new approaches in exposure assessment filed based on the latest studies carried out in the world. In this review article, according to the objectives of the study, literature related to new approaches in exposure assessment was identified through electronic searching in Scopus, PubMed and web of Science databases. After introducing new approaches, the most important sources of errors and limitations were also examined to reduce uncertainties of exposure estimation in these studies. The results of the study showed that comprehensive exposure assessment using new approaches in personalized exposure assessment, targeted and non-targeted analytical methods, -omics technologies, novel exposure matrices and computational models presented in this study can help researchers to identify the effective factors in development and increase assessor’s knowledge of mechanisms, exposure pathways and biological responses. The use of new exposure assessment approaches provides new opportunity for researchers to better understand the biological processes in the development of diseases and estimate the actual human exposure to environmental risk factors.

Hemodialysis patients with a regular physical activity and proper sleep show better physical and mental health. As increasing self-efficacy of patients can increase these behaviors, this study was aimed to evaluate the effect of the self-efficacy theory on physical activity and sleep in hemodialysis patients. This research was an interventional study performed in Qom city in 2016. Research population was consisted of 70 hemodialysis patients (35 patients in each group). The data collection instruments were demographic questionnaire, self-efficacy (SUPPH) and researcher-made validable and reliable questionnaire of physical activity and sleep, collected in two stages including before and 3 months after education. Educational program, based on the self-efficacy theory, was performed for interventional group during two half-hour sessions. Data were analyzed by SPSS version 16 with tests including independent T-test, paired T-test, Chi-square and Mann-Whitney at significance level of 0.05. In the interventional group, there was a significant differences between the mean scores of self-efficacy, physical activity and sleep, before and after education (p<0.001). Also, mean scores of self-efficacy, physical activity and sleep after education had significant differences between interventional and control groups (p<0.001). However, intradialytic weight gain (p=0.445) and systolic blood pressure (p=0.241) after education showed no significant differences between interventional and control groups. The results of this research showed that hemodialysis patients’ education based on the self-efficacy theory was positively effective on physical activity and sleep behaviors. Therefore, it is recommended to use this theory with traditional training methods.

The presence of heavy metals in urban sewage sludge limits its use as a soil modifier. The purpose of this study was to remove heavy metals (Cu, Zn, Cd and Pb) from urban sewage sludge using Acidophilic Thiobacillus ferrooxidans bacteria. In this experimental study, the sludge samples were collected from Shiraz wastewater treatment plant. Bioleaching tests were carried out in 250 ml flasks containing 100 ml fresh sludge, 15 ml Acidophilic Thiobacillus ferrooxidans bacteria and 1-4 g/L Fe+2 at temperature of 28 °C and speed of 180 rpm for 9 consecutive days. Heavy metal removal was monitored by polarograph. The optimum condition for separation of heavy metals in this method was obtained at retention time of 5 days and iron concentration of 2gr/l. Under this condition, 80% of cadmium, 78% of lead, 87% of zinc and 69.9% of copper were removed from sludge. Also, sludge dewatering was increased up to 99%. The residual concentrations of zinc, cadmium, lead and copper in sludge after bioleaching were 783, 1, 18 and 607 mg/kg, respectively, which were within the EPA's standards for agriculture. The results showed that the bioleaching method by Thiobacillus bacterium could be used as a suitable method for removal of heavy metals and increasing sludge dewatering efficiency.

Nitroanene compounds and toxic dyes are considered major pollutants in sewage of various industries. These synthetic organic compounds are highly toxic and one of the most resistant pollutants in the environment. Developing a simple and effective method to destroy non-biodegradable pollutants into non-hazardous products is one of the major challenges in environmental studies. In this study, Ag/ZnO nanocatalyst was synthesized using Euphorbia peplus L. extract through a green and simple reduction method. The catalytic activity of the biosynthesized Ag/ZnO nanocomposite was evaluated by reducing 4-nitrophenol (4-NP) and organic dyes such as Methyl orange, Congo red and Methylene blue. The Euphorbia peplus L. extract was used as a reducing and stabilizing agent in green synthesis of nanocomposite. The diameter of the Ag/ZnO nanoparticles was less than 24 nm. Biosynthesized Ag/ZnO nanocatalyst demonstrated effective catalytic activity in reducing 4-nitrophenol, Methyl orange, Congo red and Methylene blue during 330, 300, 39 and 2 s in environmental conditions, respectively. Comparison of the catalytic activity in the reduction of target analytes between Ag/ZnO nanocomposite and other catalysts reported in the literature showed better performance of biosynthesized nanocatalyst. In this study, a simple, green, economical, non-toxic and efficient method was presented to remove biodegradation-resistant pollutants using biosynthesized Ag/ZnO nanocomposite.

Hundreds of methods have been introduced to analyze various events. Hence one of the effective and principle steps in accident analysis is proper and targeted selection of accident analysis method. Traditional methods of accident analysis in complex industries are not comprehensive and examine each components of the system separately. So, the use of new systematic methods to overcome these problems may be beneficial. The aim of present study was systematic analyzing of one deadly occupational accident in a car industry. This qualitative case study of analysis of an accident leading to the death in a car industry was performed using systems-theoretic accident model and process (STAMP) in 2018. For this study, the documentation of work accidents archived from 2008 to 2012 was reviewed. Then, a description of each specific accident and constraint, hierarchical levels of control and inadequate control measures were determined, and ultimately the safety of the system was assessed in relation to each incident. In analysis of the accident in assembly line, several factors were involved and interactions between various components of the socio-technical systems were effective in the incident, among which the insufficient measures of safety unit had the higher contribution.  The STAMP technique, by determining a control structure, as a systematic approach for analyzing this incident, has included several factors in the incident and, unlike the traditional methods, has not consider the incident as a component of the system. Therefore, it can be used as a useful tool for accident analysis, especially in complex and sensitive systems.

Medical wastes are of great significance due to their potential environmental impacts. This study aimed to examine the medical waste management in hospitals of Ardabil city in 2016. In this cross-sectional study, hospitals of Ardabil city (7 hospitals) were studied. Initial data were obtained from library information, observation and checklist. Also, the quantity of produced wastes in hospitals was determined through their weighting in three consecutive days in one season. In order to evaluate other items of waste management pattern in hospitals, guidelines provided by ministry of health and medical education were used. Data analysis was performed by comparing the existing situation with rules and guidelines in Microsoft excel. The rate of produced waste in studied hospitals was obtained 2.74 to 5.70 kg/b.d. In average, general, biomedical, sharp and chemical- pharmaceutical wastes were accounted for 47.30%, 50.78%, 0.91% and 1.01% of total produced wastes, respectively. Implementation phases of waste management were matched poor to medium with laws. There was biomedical treatment system in 5 hospitals, of which 40% had proper function. Medical waste management in studied hospitals showed no suitable status and needed a planning for continuous training and performance monitoring.

Wastewater treatment plants represent one of the most important approachs for water conservation. On the other hand, wastewaters can act as a source of antibiotics in aquatic environments. The aim of this study was to evaluate the performance of the Yasooj municipal wastewater treatment plant for removal of Escherichia coli, Pseudomonas aeruginosa and Listeria monocytogenes and also the antibiotic resistance pattern of these bacteria. In this cross sectional study, samples of inlet, outlet aerated lagoon, outlet settlement lagoon and outlet effluent were collected from the wastewater treatment plant in order to count, isolate, and identify E. coli, P. aeruginosa and L. monocytogenes. Antibiotic resistance pattern was investigated using disk diffusion method for 6 different antibiotics according to CLSI reference method. E. coli, P. aeruginosa and L. monocytogenes were isolated and identified in all levels of purification of wastewater treatment plants. The effectiveness of sewage treatment processes to remove E. coli, P. aeruginosa and L. monocytogenes was 54.17-99.33 in the outlet effluent. The bacterial isolates showed high rate of resistance against cefixime and trimethoprim-sulfamethoxazole and low resistance to imipenem. Multidrug resistance pattern (double and triple) was observed in bacterial isolates. This study showed that antibiotic-resistant bacteria in the outlet effluent are discharged into the environment. Further research needs to be undertaken to improve sewage treatment technologies, thereby producing a better quality treated sewage effluent.

Heavy metals in urban parks are one of the most important indicators of urban pollution, as children playing in the park can readily be affected. This research was conducted to evaluate the environmental pollution of some heavy metals in Ahvaz parks. To this end, 26 sampling stations were selected from 20 parks in Ahvaz city and the soil samples were analyzed by inductively coupled spectroscopy (ICP-OES) method. The pollution levels of heavy metals were calculated based on enrichment factor, Index of Geo accumulation, pollution index and Nemerow integrated pollution index. The average concentrations of heavy metals of Cr, Zn, Ni, Pb, Cu and V were 167.26, 131.92, 78.75, 51.83, 28.71 and 12.49 mg/kg, respectively. The average concentrations of all heavy metals except Cu and V were several times higher than the base content. Based on the average EF and PI in the study area, heavy metals of Ni, Zn and Pb had high contaminations. Moreover, the highest mean of Igeo was related to Ni, Zn and Pb. According to NIPI results, 100% of samples had high degree of contamination. The results showed that the contamination source of evaluated metals was anthropogenic activities, including vehicle traffic and burning fossil fuels. Parks in Ahvaz were polluted by heavy metals, so these results may be useful for planning, risk assessment and decision making by city administrators.

Job Burnout in nurses is a barrier to job promotion and achievement to job related goals which results in reduced hospital performance. This study aimed to identify prevalence of job burnout among nurses in Iran. This study was conducted using a systematic review. All published articles on prevalence of burnout among nurses in Iran from 2000 to 2017 were searched and collected using PubMed, Web of Science, Science Direct, Scopus, Magiran, IranMedex, SID and Bibliography section of the retrieved papers and related journals. Finally, 32 studies which were suitable for inclusion in the study, were reviewed using Comprehensive Meta-Analysis software. The overall prevalence of job burnout in Iran's hospitals was 25 % (95% Cl 19%-32%) during 2000-2017. The highest job burnout was recorded in Tehran in 2009, 75% (95% Cl: 65%-82%) and the lowest in Hamedan in 2016, 0/2% (95% Cl: 0.1%-0.4%). Significant statistical correlations were observed between job burnout, year of study, nurses' age and sample size (p<0.05). Occupational burnout affects about one-third of nursing staff in Iran. Thus, managers and policymakers should take serious measures to reduce the prevalence of job burnout among nurses.

One of the factors affecting the performance of video display terminal users is their mental work load. Since low sleep quality causes fault and decreased accuracy in work, this study aimed to evaluate the relationship between mental work load and sleep quality in video display terminals users. This descriptive cross-sectional study was performed on 191 video display terminal users. National Aeronautics and Space Administration Task Load Index questionnaire (NASA TLX) which is a six-dimensional tool and measures mental, physical, temporal, performance, Frustration and Effort demands, was used in the study. For evaluation of sleep quality, Pittsburgh Sleep Quality questionnaire was used. Data were analyzed by descriptive statistics, independent T-test, one way ANOVA, Pearson correlation coefficient and regression analysis in SPSS version 20 software. Mean score of sleep quality and mean of overall mental work load were 6.29±2.67 and 66.61±17.69, respectively. Pearson correlation coefficient showed no significant relationship between mental work load and sleep quality (p=0.34, r=-0.06). Independent T-test showed that there was a significant difference in sleep quality between males and females (p=0.001). 39.2% of participants demonstrated good sleep quality, 4/52% relatively low quality and 4/8% low sleep quality. NASA-TLX showed that the lowest and highest scores of six scales were related to physical demand (16.27±22.43) and mental demand (78.57±21.31), respectively. In this study, there was no significant relationship between mental work load and sleep quality. Since mental work load was high in video display terminal users, use of effective programs to reduce the mental work load seems to be essential for these users.