vafa hamid

Given the fact that the Karun River, as the most important source of water supply in Khuzestan province, has recently been affected by various pollutants such as sewage, monitoring its water quality is a necessity. This study aimed to determine the water quality of the Karun River based on biological indicators (Daphnia-crustaceans).
In each season of the year, water samples were obtained from three stations at three different points along the river. After measuring the physical and chemical parameters, the samples were left to settle for 24 hours in the laboratory. Then 1 cc of the sediment was placed on the slide to study the diversity and frequency of crustaceans. Data were analyzed using SPSS version 21.
In the present study, the frequency and variety of crustacean species isolated from the samples decreased from the initial station of the river to the final station. In addition, 27 species of Protozoa were isolated from three stations, of which Daphnia and Rotifer species with an average of 2.166 and 4.833 and standard deviation of 1.984 and 5.166, respectively had the highest frequency compared to other species. The results of the Pearson correlation showed that there is a direct and statistically significant relationship between dissolved oxygen (DO), Turbidity, Daphnia, and Rotifers.
Based on the results of this study, it can be stated that the entry of effluents into river water causes a significant reduction in water quality, which in turn reduces the diversity and frequency of crustaceans living in the water. This is possibly due to an increase in sewage discharge from Ahvaz city to Karun river.

Recently, the spread of the coronavirus disease 2019 (COVID-19) has increased among workers of meat processing plants (MPPs) around the world. This study reviewed the possible routes of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission and useful actions against it in slaughterhouses. The results revealed that the main factors for the spread of the virus included low indoor temperature, crowded area, wrong standing along production lines, contamination of high-touch surfaces, difficult education of workers with diverse native languages, low financial income, large MPPs with over 10 million Ib of packed meat per month, higher speed of production lines with 175 birds/minute, temporary contract of the workers, and weak approach of some meat processing companies against COVID-19 infection such as National Beef. COVID-19 transmission rate was 24 times higher among the workers of MPPs than among the population of the US. The practical actions against the spread of the virus were mainly marker using for remembering the previous location, mandatory mask use, especially FFP2/3 masks, and decentralization of large MPPs. By using the results of this study, slaughterhouse managers would be able to significantly control the spread of SARS-CoV-2 and future bio-threats to workers of MPPs and even to society.

Perfectly clean air cannot be found in nature. It contains a certain abundance of particles, including dust, dirt, soot, smoke, and liquid droplets. Mounting evidence indicates increase in particle concentrations and health effects attributed to them in developing countries. In this work, we focused on the determination of number of cardiovascular, respiratory diseases and total death associated with PM2.5 in Karaj city during 2012 to 2015. The health effects of PM2.5 concentrations in ambient air of Karaj was determined using AirQ+ software. Air pollution data was obtained from the Department of Environmental Protection of this city. To validate the data, WHO criterion was performed. After all, data processed by Excel was given to the model. The annual average PM2.5 concentrations in ambient air of this city during the study was higher than WHO health protective guideline (10 µg m–3). The concentration of pollutant has been reduced during the study period but there is a sudden increase in 2015. In addition, the most attributable proportion was estimated in Karaj in 2012 (59.04% for long-term and 5.86 for short-term effects). PM2.5 exposure has caused 275 and 60 natural deaths due to long-term and short-term exposure in 2012 which is unexpected. Regarding the health effects of PM2.5 in ambient air of Karaj city, the importance of controlling air pollution in this metropolis is becoming increasingly evident.