Analysis of NOx, NO and NO2 ambient levels in Dhahran, Saudi Arabia

NOx, NO, and NO2 concentrations and meteorological parameters, temperature, wind speed, relative humidity and pressure were measured continuously in Dhahran from May to July 2015. Concentrations of NOx, NO, and NO2 were found to be highly influenced by traffic emission and meteorological conditions. The temperature and wind speed showed negative correlation coefficients while relative humidity showed positive correlation coefficient with NOx, NO, and NO2 concentrations. NO2 was found to exceed international air quality standards, which indicates the existence of possible NO2 air pollution problem in Dhahran. (C) 2017 Elsevier B.V. All rights reserved.