فصلنامه پژوهش در بهداشت محیط
سال ششم شماره 3 (پاییز 1399)

The workplace, as a place where employees spend long hours and possibly interact with many people, is one of the most susceptible environments for transmitting the corona virus, so to minimize the risk of contracting the virus, adhere to health protocols in these environments. It is very important. Due to the lack of environmental health forces, the size of the departments, inspection and sensitization training of employees of all departments regarding the observance of coronavirus prevention protocols is not possible. Therefore, the authors in this article suggested the ambassadors of office health as participants in the health of the organization. A health ambassador is an employee of the organization who is the liaison between the health system and the employees of that organization. After receiving face-to-face and face-to-face training on coronavirus prevention health protocols by environmental health experts, the organization's health ambassador can carry out coronation prevention and control activities in their organization. The present study identified the importance of empowering health ambassadors of organizations as selected organizations to prevent coronavirus disease, will interrupt the transmission of coronavirus disease chain in employees.

Tehran, as the largest and most populous city in Iran, has encountered many problems, of which air pollution is the most common. In recent years, PM2.5 has been the cause of the unhealthiest days in terms of air pollution in Tehran; For this purpose, the present study was conducted with the aim of Spatio-temporal analysis of PM2.5 pollutant in the Tehran metropolis during the years 2014-2017 using GIS.

In this study, Inverse Distance Weighting (IDW) and HotSpots methods have been used to predict and zoning of PM2.5 concentrations during four consecutive years (2014-2017).

The results of hotspot analysis and Getis-Ord-Gi index showed that the southern and southwestern regions with a confidence level above 90% and a concentration of more than 50 μg/m3 are the most polluted areas. And to a lesser extent, the western and central areas are next.; Also, the concentration of PM2.5 pollutants shows an increasing trend from north to south and east to west.

South, southwest, west, and center are the most polluted areas; However, the present study only shows the zoning of PM2.5 concentration and does not identify the various factors and the contribution of each of them in the production of this pollutant; And it is necessary to conduct studies to identify sources and their contribution to control and reduce the concentration of PM2.5 in the Tehran metropolitan.

Today, fluorescent lamps are the most common light source in the world and Iran. Mercury in these lamps may enter the environment and cause harmful effects. The aim of the present study was to investigate the effect of heterotrophic wastewater bacteria on the mercury removal from fluorescent lamps.

In this study, different components of lamps were separated using a crushing machine and then mercury was separated from phosphorus powder by acid washing. Bacteria isolated from wastewater were exposed to mercury from acid wash and the mercury content in the lamps was measured by atomic absorption spectrophotometer. The highest concentrations of mercury extracted from lamps was 86.03 ppb in the ratio of 4 HCL: 1 HNO3, and the lowest mercury concentration was14.03 ppb in the 1HCL: 1HNO3 ratio.

The results of this study showed that heterotrophic bacteria can reduce mercury levels to less than 5 µg / L. 19 bacteria purified from wastewater were resistant to mercury chloride at concentrations of 5 and 10 mg. Also, 10 bacteria were able to reduce mercury. The highest rate of mercury reduction (92.24%) was related to Pseudomonas marginalis and the lowest rate (62.47%) was related to Pseudomonas simiae.

This study showed that heterotrophic sewage bacteria can be used as an efficient, low-cost, and environmentally friendly method for detoxification of mercury from out-of-date fluorescent lamps.

Today, the supply of qualified drinking water has become the main concern of the competent authorities. Drinking water, in addition to the appropriate quantity, must have appropriate standards regarding physicochemical and microbial properties. Nitrate and nitrite ions are of special importance due to their adverse environmental and health. The aim of this study was to determine the concentration of these ions in the drinking water of Evaz city and to perform calculations related to health risk assessment.

In this study, five points were selected and 50 samples (10 samples from each point) were collected over time intervals. After transferring the samples to the environmental chemistry laboratory, the concentration of nitrate and nitrite ions was determined by the spectrophotometer (DR6000) according to the instructions provided by the HACH.

The concentration of nitrate and nitrite ions in all parts of the network was lower than the standard set by the WHO. The highest and lowest concentrations of nitrate and nitrite ions were obtained at the sampling sites of Patrice Restaurant (1.04 and 0.021 mg/L) and ABFA (0.8 and 0.0162 mg/L), respectively. Also, risk assessment based on the age range of infants, children and adults was 0.125, 0.00375 and 0.043, respectively, which shows that long-term water consumption will not have a negative impact on human health.

The physicochemical quality of Evaz drinking water was acceptable and human exposure to this water has a non-carcinogenic risk of much less than the critical range.

Increasing population and urbanization density and as a result increasing impermeable levels, led to an increase in the volume of urban runoff. Applying simulation models is a suitable way to know the amount of runoff quality parameters. This study aims at evaluating the quality of urban runoff in Shushtar city using storm water management model (SWMM).

Two given rainfall events in 1395 for calibration and validation of the model were considered. The parameters related to the first rainfall event were measured at the outlet of the urban drainage system. Quantitative and qualitative calibration of the model was performed using the first rainfall and model validation was performed using the second rainfall.

In the hydraulic calibration, mean values of impermeability, slope, catchment width and manning coefficient were estimated to be 50%, 75%, 25 m and 0.013, respectively. In the qualitative calibration, the coefficients of the Build-up equations for TSS, COD and Zn were equal to 95-25, 48-1, 1- 0.09, respectively. The coefficients of Wash-off equations for TSS, COD and Zn were estimated 0.21- 0.8, 0.2-0.8 and 0.19-0.78, respectively.

The results showed that the accurate calibration of the model enhances the ability of the model to estimate the quantitative and qualitative parameters in future rainfall events for the study area. According to the results, the modeling is a powerful tool that can be very useful to improve runoff management.

Water quality is an important factor that affects all aspects of eco-system and health food-to-business activities to the sustainability and health of the echo systemThis study was carried out with the aim of investigating the qualitative changes in the Ziarat River water.

Samples from the Ziarat River Station (5 stations) were sampled each year in 2018. Samples were transferred to the Golestan University of Medical Sciences in accordance with the standard conditions, along with ice. The parameters of nitrate, phosphorus, biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonium, total hardness and total Fecal coliform was measured according to standard method and the Water Quality Index (WQI) was calculated.

The results of the study, based on the WQI index, showed that the index for all stations was between 29.68 and 64.78, and in some of them the average was (50-70) and some stations had poor quality ( 50-25). The most effective parameter on the water quality of the river is the BOD parameter, and then it is the total solids, turbidity, phosphate, nitrate and total Fecal coliform.

The highest level of pollution in the terminal stations (4 and 5) due to more industrial activity is the entry of sewage and effluents into the river in Gorgan. Among the measured parameters of nitrogen and phosphorus as nutrients, if left unchecked, it poses a risk of eutrophication. Agricultural, livestock and recreational activities around the river affect the water quality of the river. So that a more appropriate quality was observed in the upstream stations. Considering that the Ziarat River is one of the most important sources of water supply needed in the agricultural and industrial sectors in Golestan province. Therefore, monitoring and control of pollutants entering this river is essential.

In recent years, the rapid growth of cities has been led to an increase in the production of various types of solid wastes in urban areas. Although landfilling is the last step in municipal solid waste management, but it is one of the common methods in developing countries’ municipal solid waste management. The purpose of this study is to accurately locate urban landfills in Naien county by using a combination of fuzzy and boolean methods.

In this study, AHP model was used to standardize and determine the weight of criteria and sub-criteria. The innovation of this research is the combination of the results of fuzzy and boolean logic. The fuzzy method consists of two groups, the first group is calculation the weight of criteria and the other one by calculating the weight of sub-criteria, and the results of boolean logic with five classes including calculation the weight of criteria and sub-criteria.

The results of this study show that the mentioned fuzzy and boolean methods have identified 34, 48779, 16000 and 7630 hectares of areas in Nain county as the most suitable areas for creating urban landfills. According to the weight of methods, a single map with four main patches is resulted by combination of these four methods, which includes a total of 5055 hectares in Nain.

The results of this study show that the combination of fuzzy and boolean logic results provides better areas for landfill than using the methods individually.

The garbage economy is now expanding as a kind of hidden and informal economy and obviously has its causes and consequences. Given the importance of this huge portion of working capital, this study evaluates the economic performance of the centers. Solid waste recycling is discussed.

This research is a cross-sectional descriptive study. In this study, the process of economic performance assessment of solid waste recycling centers in Jouybar and Qaemshahr towns in 2018 was studied with 90 randomly selected workshops. Data analysis was performed in SPSS version 24.

This study shows that 60,700 kg of waste is pumped into recycling plants daily. 1% of all workshops have a productivity of less than 100 kg, 20% of all workshops have a productivity of between 100-300 kg, 39% of all workshops have a productivity of between 300-500 kg and 40% of All workshops have a production volume exceeding 500 kg. The value of manufactured products used as raw materials of factories According to Rial calculations in 2018 is about 912765000 Rials daily, without economical saving in disposal costs.

The high potential of income generated by the activity of segregation and waste collection is significant in the riverside and upstream cities. Considering the hygiene at the source, in addition to high economic income and savings in waste disposal, entrepreneurship and employment Also provided a lot.