The evaluation of Tabriz mega-city air quality according to air quality index (AQI), in 2011

Nowadays megacities air pollution has considered as a health problem, which caused various health effects such as cardiovascular and pulmonary disease and so on. Therefore air quality monitoring is needed for citizens informing as well as offering of new strategies for pollution control. So the aim of this study is the evaluation of Tabriz megacity air quality according to criteria pollutant concentration.

In this cross-descriptive study, five criteria pollutant concentrations were derived by referring to East Azerbaijan environmental protection organization. AQI was calculated by specific equation with using moment concentration of criteria pollutants. Then according to air quality standard level table, calculated indexes were categorized in relevant level. Statistical analysis was done with SPSS20 descriptive tests and Excel2010 software.

Of total 366 days, the air quality statue in 4.1% of days were good, 65% moderate, 24.8% unhealthy for sensitive group, 2.2% unhealthy, 3.3% very unhealthy and 0.6% hazardous. Also in 30.87% of days the AQI have been extreme standard level. CO with highest quota was responsible pollutant. Maximum level of three main pollutants of PM10, CO and O3 was in March, October and June months, respectively.

Tabriz air quality in 2011 was not desirable, as 112 days of year; pollutant levels were higher than allowable limit. Seasonal variation has significant correlation with pollutant levels; theretofore consideration of this factor probably can be useful to definition of control strategies. Increasing of monitoring stations can be utilize for obtaining extensible statistics average for hole of city.