Background and Aims: Ammonia is a toxic gas and is used as a refrigerant due to its special thermodynamic properties. This study was designed to evaluate the toxic effects of ammonia leakage in an industrial refrigerator. Materials and Methods: The present study was conducted in an industrial refrigerator in 2019. Due to its widespread use in industrial refrigerators, reservoirs containing ammonia gas were selected as the center of hazards. Given the potential damage of this chemical, only the toxic dimension of this gas was evaluated. Also, owing to the importance of determining the extent of human vulnerability, the scenarios were evaluated in the worst condition and in the case of the catastrophic rupture of reservoirs. Consequences modeling of selected scenarios was performed using PHAST 7.2 software. Results: The obtained concentration profiles showed that during the first and last six months of year, reservoir 1 with up to respectively 570.20 and 349.09 meters beyond it in the wind direction, located on the ERPG3 level, according to ERPG (Emergency Response Planning Guidelines) levels. Likewise, in reservoir 2 between 891.05 and 556.74 m from the reservoir, during the first and last six months of the year, located on the ERPG3 level, respectively. Conclusion: Catastrophic rupture of ammonia tanks and its dispersion into the environment can cause a high mortality rate. Therefore, implementation of preventive programs such as emergency response planning appropriate to the potential hazards of ammonia gas, development of a comprehensive risk management plan, determining the correct location of reservoirs following the results of consequence modeling, etc. can be effective steps in reducing the consequences in the case of such accidents.

Background: Upper gastrointestinal cancer (UGIC), including gastric and esophageal cancers, is one of the major causes of cancer related death in the world. The aim of this study was to explore the relation between family history of cancer and the risk of UGIC in Iran. Material and Methods: The present study is a case-control study conducted on 106 patients with UGIC, 106 hospital controls and 106 population controls that were matched in terms of age and sex. Data were collected using a standard questionnaire. Face-to-face interviews were conducted to collect data through a standard questionnaire. Logistic regression models by conditional forward method were used to estimate the odds ratio (OR) with 95% confidence interval (CIs) and to determine the significant relationship between UGIC and family history of cancer. SPSS 22 software and chi square test was used for data analysis. Results: Family history of cancer showed a significant relationship with UGIC in the case group-hospital control in the first and second degree relatives (9.04 - 2.18), respectively: 95% CI) OR = 4.44 and (1.3 - 9.27): 95% CI) OR = 3.48, in the case-control group of population in first and second degree relatives (3.74-75.75: 95% CI) OR = 9.43 and (83-21-97) / 1): 95% CI) OR = 6.35. Conclusions: The findings of this study showed that a family history of cancer, especially in the first-degree relatives, increases the risk of UGIC, which requires more extensive studies with a larger sample size.

Background and Aims: Particulate matter are effective factors in the spread of viruses, fungi and bacteria that can affect the prevalence of epidemics. In this study, we surveyed the effects of particulate matter on the number of COVID-19 patients in Iranian cities. Materials and Methods: The levels of air pollution in different cities of Iran were evaluated based on the official report of Iranian Department of Environment. The relationship between air pollution and the prevalence of affected COVID-19 patients in different cities was reviewed and analyzed. Results: The results showed that COVID-19 were prevalent in cities with the highest level of air pollution in fourteen days before the observed rise in the number of affected cases. Conclusion: The increase in the rate of COVID-19 patients in dusty cities in Iran emphasized that particulate matter may be effective in the increasing number of COVID-19 patients. Further studies on the effect of airborne pollutants on the prevalence of epidemics are thus recommended.

Background: Health care centers wastes (15-25% hazardous waste) are the second most dangerous waste in the world.Hospitals and medical centers are the major sources of health-care waste generation. The aim of this study was to investigate the effect of waste management promotion program of Razi hospital in Qazvin, Iran during 2013-2018 (6 years). Materials and methods: This interventional study was conducted during 6 years (2013-2018), in which hospital wastes were collected in four main categories quantitatively and the relevant data were collected. Descriptive statistics of percentage and mean were conducted for data analysis using Excel software. Ethical considerations were observed at all stages of the study. Results: The results showed that the rate of general and hazardous waste generation were 53.3% and 46.7%, respectively. With the implementation of waste management promotion program in 2014 and 2015, hazardous and ordinary wastes percentage reached to 35% and 65%. Similarly, the contribution of hazardous wastes fell down to 32.7% versus to 67.3% of general waste in 2016. Likewise, hazardous wastes were 33.4% and normal wastes were 66.6% in 2017; and in the following year (2018), the contribution of hazardous and general wastes were 30.3% and 69.7%, respectively. Conclusion: Based on the findings of the present study and comparing them with the mentioned studies, waste management promotion programs in Razi Hospital have been effective. However, it remains far from WHO standards in the field of hazardous waste generation and necessitates continuation of programs and continuous improvement of them.

Nowadays, the vital role of risk management process in controlling hazards is evident. One of the main goals of this process is sought to control hazards through risk control measures. It seems, however, that the vital problem of evaluating risk control measures has been less studied. As a result, from a pool of risk control measures some are chosen and implemented just mentally without any evaluation or theoretical background. This problem can be considered as a critical factor in the risk management process due to resource restrictions of an organization. Given the importance of the process of evaluating risk control measures and ignoring it in most risk management processes, we reviewed advantages and disadvantages of the classification and prioritizing patterns of control measures extracted from literature. A conceptual framework was also proposed to develop a practical and comprehensive method in the process of evaluating risk control measures. Ethical considerations were observed in all stages of the study. The results revealed that most of the evaluation methods designed for risk control measures are not able to prioritize them accurately due to the use of inappropriate or limited criteria and methods. Based on the conceptual framework developed, it was suggested to create a practical and comprehensive method with regard to risk factors, quality factors (effectiveness, cost, reliability, duration, usability, and applicability) and Haddon hazard control matrix using multi-criteria decision-making methods in order to evaluate control measures.