Characteristics of Surface Ozone Concentrations at Stations with Different Backgrounds in the Malaysian Peninsula

One of the main challenges for countries in tropical areas is the high concentration of ozone caused by elevated levels of anthropogenic and natural ozone precursors. In this study, variations in O3 concentrations from urban, suburban and rural regions of the Malaysian Peninsula were investigated using data covering a five-year period (2005–2009) obtained from the Malaysian Department of the Environment. The principal aim of the study is to identify and describe the variations in O3 concentrations recorded at three monitoring stations with different backgrounds, namely Petaling Jaya (S2) (urban), Putrajaya (S1) (suburban) and Jerantut (S3) (rural). The study also investigated the relationship between O3 distribution and its association with nitrogen oxides (NO and NO2) and non-methane hydrocarbon (NMHC). The results showed that the highest O3 concentration was recorded in a suburban area (Putrajaya (S1) with an average daily maximum value of 60 ± 20 ppbv). The O3 concentration was influenced by the characteristics of nitrogen oxides, particularly the titration of NO. The surface O3 level was found to be influenced by solar radiation and wind direction from the busy areas, most notably Kuala Lumpur’s city centre. This study suggests that the emission of O3 precursors, particularly NOx from motor vehicles, needs to be regulated to reduce the incidence of high O3 levels in Malaysia.