An Analysis of Air Pollution in Makkah - a View Point of Source Identifcation Turki M. Habeebullah The Custodian of the Two Holy Mosques Institute for Hajj and Umrah Research, Umm Al-Qura University, Makkah, Saudi Arabia Abstract Makkah is one of the busiest cities in Saudi Arabia and remains busy all year around, especially during the season of Hajj and the month of Ramadan when millions of people visit this city. This emphasizes the importance of clean air and of understanding the sources of various air pollutants, which is vital for the management and advanced modeling of air pollution. This study intends to identify the major sources of air pollutants in Makkah, near the Holy Mosque (Al-Haram) using a graphical approach. Air pollutants considered in this study are nitrogen oxides (NOx), nitrogen dioxide (NO 2 ), nitric oxide (NO), carbon monoxide (CO), sulphur dioxide (SO 2 ), ozone (O 3 ) and particulate matter with aero-dynamic diameter of 10 um or less (PM 10 ). Polar plots, time variation plots and correlation analysis are used to analyse the data and identify the major sources of emissions. Most of the pollutants demonstrate high concentrations during the morning traffc peak hours, suggesting road traffc as the main source of emission. The main sources of pollutant emissions identifed in Makkahwere road traffc, re-suspended and windblown dust and sand particles. Further investigation on detailedsource apportionment is required, which is part of the ongoing project. Keywords: air pollution; source identifcation; Makkah; sources of air pollution The international journal published by the Thai Society of Higher Education Institutes on Environment Environment Asia Available online at www.tshe.org/EA EnvironmentAsia 6(2) (2013) 11-17 1. Introduction Air quality in Saudi Arabia has improved signifcantly sincethe installment of several sulphur recovery plants in Saudi Aramco refneries and the beginning of emission monitoring by the Presidency of Meteorology and Environment (PME) and Saudi Aramco Air Quality and Meteorological Monitoring Network stations. However, during the last decade due to the rising per capita income the number of registered vehicles in Saudi Arabia has increased by 45%. It is predicted that during the next decade, annual demand for diesel and gasoline fuels might grow at an average rate of 4%, reaching about 1.5 million barrel per day in 2018. This may increase the emission of traffc related air pollutants. At present generally the concen- trations of traffc related gaseous air pollutants (e.g., nitrogen oxides (NOx), carbon monoxide (CO), sulphur dioxide (SO 2 )) are below the air quality standards set by World Health Organisation (WHO) and PME (Ha- beebullah et al., 2012), however the concentrations of particulate matter (PM) and ozone (O 3 ) sometimes violate the air quality limits. High levels of particulate matter with aero-dynamic diameter of 10 micronor less (PM 10 ) in Makkah, especially during the Hajj period have been previously reported by several authors (Nasralla, 1983; Othman et al., 2010; Khodier et al., 2012). The reasonsfor the high PM 10 concentrations are most probably high volume of traffc, construction work, re-suspension of particles, windblown dust and sand particles and geographical conditions (Arid Regions) (Khodier et al., 2012). Most of the area of Saudi Arabia is made of deserts, which leads to a high concentration of dust in the air as wind blows onto inhabited areas from the neighboring desert lands (PME, 2012). The government of Saudi Arabia is continuously working on improving the air quality in Makkah. Steps undertaken for the reduction of air pollutant concentrations include the development of electric train system, continuous water spray program in the Holy Mosque, which has shown positive effect on PM 10 concentration and reducing the number of vehicles in the Holy Sites (Mina, Muzdalifah and Arafat), especially during the Hajj period. Identifying the sources of emissions and quantify- ing their contribution are vital for effective management and advanced modeling of the air pollution; however no published literature was found regarding the source apportionment of air pollutants in Makkah. In this study the authorintends to analyseair pollutants data in a view to investigate their temporal variations and identify different sources of air pollutants in Makkah near Al-Harm using correlation analysis and graphical presentations.