Status of CO as an air pollutant and its prediction using meteorological parameters in Tehran, Iran

Abstract

In the present study air quality analyses for Carbon monoxide (CO), were conducted in Tehran, Capital of Iran. The measurements were taken in four different locations to prepare average data in the city. The average concentrations were calculated for every 24 hours, each month and each season. Results showed that the highest concentration of CO occurs generally in the morning and beginning of night while the least concentration was found at the afternoon and early morning. Monthly concentrations of CO showed the highest value in January while least value was found in July. The seasonal concentrations showed the least amounts in summer while the highest amounts in autumn. Relations between the air pollutant and some meteorological parameters were calculated statistically using the daily average data. The wind data (velocity, direction), relative humidity, temperature, sunshine periods, dew point and rainfall were considered as independent variables. The relationships between concentration of pollutant and meteorological parameters were expressed by multiple linear and nonlinear regression equations for both annual and seasonal conditions using SPSS software. RMSE test showed that among different prediction models, stepwise model is the best option.