عنوان مقاله [English]
Considering that conducting studies on the emission and concentration of pollutants in the air is one of the key measures to maintain the quality of the environment and, of course, towards the goals of sustainable development, so it can be said that by studying air pollution in industry Oil, to be able to predict the situation of sensitive areas in the future and to deal with possible adverse events, to provide appropriate ways to prevent, deal with and mitigate the consequences. This complex is located in the main flower path of Ahvaz city and directs the exhaust gases directly from the flares of this complex to the western part of Ahvaz. This is a non-interventional and descriptive-analytical study that was conducted in the summer of 1398 in Ahvaz. Ahvaz city with a population of 1059461 people was located at 31.20 north latitude and 48.40 degrees east longitude. The province is arid and semi-arid in terms of weather conditions and is affected by winds from neighboring countries, especially Iraq, as well as winds originating in the Persian Gulf.
After conducting comprehensive studies on the climatic and geographical situation of Ahvaz city and according to the map of Ahvaz flower garden, the exhaust gases from the flares of oil and gas exploitation complex No. 3 in the west of Ahvaz, were considered as a source of pollutants. This complex consists of an operation section with gas and diesel fuel consumption and 3 long burners, 3 short burners and 70 fuel pits, a desalination section with gas fuel and has 2 short burners and a gas pressure boosting station with gas and diesel fuel. It consists of 2 long burners, 1 cold burner and 1 fuel pit. Concentrations of NO2 and CO2, SO2, CO were measured by Enviro SA and Ecotec analyzes. Monitoring of gases and suspended particles was measured in summer and once a month (3 times in total) at intervals of 50, 100, 500, 1000, 2000 and 3000 meters in four directions north, south, west and east of the complex. Figure 2 shows the location of the sampling location. In order to calculate the AQI index, the information obtained from the sampling points according to the table of national standards of open air quality and air quality index were converted into the standard mean time concentration. According to these standards, a maximum concentration of 8 hours was used for carbon monoxide, a maximum concentration of 1 hour for nitrogen dioxide, and a mean concentration of 24 hours for suspended particles and sulfur dioxide. The maximum concentration of CO gas was measured during 24 hours. A maximum concentration of 8 hours and a maximum concentration of 1 hour were used for ozone, an average concentration of 24 hours for suspended corn and sulfur dioxide, and a maximum concentration of 1 hour for nitrogen dioxide. The results of the values related to air hygienic quality indicators of O3, NO2, SO2, CO gases in summer along with changes in air hygienic quality are shown in Table 3. Accordingly, in summer, SO2 gas was very unhealthy up to a distance of 50 meters and NO2 and CO gases were unhealthy up to a distance of 500 meters. CO was very unhealthy at 2000 and 3000 meters in the east, NO2 at 1000 meters east and south and So2 at 3000 meters. O3 gas except at a distance of 50 meters south (Golbad route) with a rate of 0.098 ppm and at a distance of 50 meters west with a rate of 0.09 ppm and a distance of 100 meters east of the complex with a rate of 0.082 pm which was unhealthy In other respects, he was clean and healthy. The quality of PM2.5 particles was 50 meters north and south, 2000 meters south, north and east and 3000 meters in four directions of unhealthy pollution. Healthy condition was measured only in the east direction of Feller at distances of 500 and 1000 m and in the west direction at a distance of 1000 m. PM10 particles except at a distance of 50 m in the south (unhealthy for sensitive groups), 2000 m in the east, south and north (unhealthy for sensitive groups) and west (very unhealthy), 3000 m in the east and north (Unhealthy for sensitive groups) and west (dangerous) showed health in other directions and distances. The case of NO2 gas had Ip index in the distances of 50 and 100 areas to the west and south, a distance of 500 to the north and a distance of 1000 meters in the east at a distance of 2000 and 3000 meters in the west and north. O3 gas at the distances of 100, 50, 500 and 1000 meters had the highest value of Ip index in the south and at the distances of 2000 and 3000 meters in the west (Figure 4). So2 at distances of 50 and 1000 meters in the east and at distances of 100 and 500 meters in the south, at distances of 2000 and 3000 meters in the north and west (Figure 5) and CO at distances of 50 meters in the north, at distances of 100, 500 and 1000 Meters in the south and between 2000 and 3000 meters in the west had the highest Ip index. The Ip index was highest for PM2.5 particles at distances of 50, 100, 500 and 1000 m in the south and in the direction of west at 2000 and 3000 m (Figure 7). The Ip index for PM10 particles was highest in the west at distances of 50, 100, 500, 2000 and 3000 m and in the south at a distance of 1000 m (Figure 8). PM2.5 particles in the west direction and PM10 particles mainly in the east direction had the lowest amount of suspended particles, which is indicated by arrows.In terms of air quality index, PM2 .5 particles in healthy to very unhealthy condition and PM10 particles except at one point in the west at a distance of 2000 and 3000 meters, which showed very unhealthy and dangerous condition in most parts of the healthy condition. In the case of PM2 / 5 particles, which can be justified due to the location of Ahvaz in a dry area and the wind from the surrounding dry areas, which is also associated with light dust particles, also in the west direction, high vehicle traffic on the Ahvaz-Dezful road The access road to the industrial town is also the license plate exchange center, and in the south and southwest of Meyvan va Tarbar Square, as well as Al-Ghadir Stadium and the air defense residential areas, the cause of the high degree of air pollution is particles. The point that is determined by the overlapping of the values of the indicators with the sampling location map is the increase in the intensity of pollution according to the existing urban infrastructure at any point in a way that in the west of Feller by distance from Feller to Up to a radius of 1000 meters due to the lack of urban facilities, a decrease in air quality index gases and suspended particles was observed, but in the range of 2000 and 3000 meters with increasing urban activities and vehicle traffic centers such as fruit and vegetable center and highway. Ahvaz - Dezful and license plate replacement center, the level of pollution with CO and NO2 gases increased, and in fact, these infrastructures play the role of a flare with high CO gas emissions. While in the range of 1000 meters in all four directions of Feller and also 500 meters in the east of Feller and the north due to the existence of agricultural lands and limited rural populations, indicators of a better situation compared to points 50 and 100 Meters near the complex. Also, the situation of So2 gas at a distance of 2000 meters was clean and at a distance of 3000 meters, respectively, it became unhealthy twice. The city can reduce the concentration of this gas in the air and reduce its concentration due to the lack of natural barriers in the area and the lack of new sources of pollution, but at a distance of 3,000 meters of roads act as a new source and they increased the load of So2 contamination.
According to the above findings, the presence of oil and gas exploitation complex No. 3, along with the high density of urban service centers such as stadiums, fruit square and central transport of Ahvaz, license plate replacement center, Modares highway and busy road Ahvaz - Dezful and with Paying attention to the direction of Golbad acts as an aggravating factor for the residents of western Ahvaz, which can lead to many health injuries for citizens, even in the short term, including the short-term and acute effects of PM2. 5.2, NO2 and CO were noted for respiratory disease and mortality as well as due to the presence of farms on food crops.