Temporal Characterisation of Ground-level Ozone Concentration in Klang Valley

School of Environmental Engineering, Universiti Malaysia Perlis (UniMAP), Kompleks Pusat Pengajian Jejawi 3, 02600 Arau, Perlis, Malaysia.

^* Corresponding author: norazian@unimap.edu.my

Abstract

In Malaysia, ground-level ozone (O₃) is one of the most significant air pollutants due to the increasing sources of ozone precursors. Hence, the surface O₃ concentration should have received substantial attention because of its negative effects to human health, vegetation and the environment. In this study, hourly air pollutants dataset (i.e O₃, Carbon monoxide (CO), Nitrogen dioxide (NO₂), Particulate matter (PM₁₀), Non-methane hydrocarbon (NmHC), Sulphur dioxide (SO₂)) and weather parameters (i.e. wind speed (WS), wind direction (WD), temperature (T), ultraviolet B (UVB)) for ten years period (2003-2012) in Klang Valley were selected for analysis in this study. Two monitoring stations were selected that are Petaling Jaya and Shah Alam. The aim of the study is to determine the diurnal variations of O₃ concentrations according to the seasonal monsoon and the correlation between the ground-level O₃ concentration and others parameter. A high concentration of ground-level O₃ was observed during the first transition (April to May) for both of the stations. While at a low surface, O₃ concentration was found out during the southwest monsoon within June to September. Pearson correlation was used to find the correlation between the O₃ concentration and all other pollutants and weather parameters. Most of the relationship between O₃concentrationswas positively correlated with NO₂ and negative relationship was found out with NMHC. These results were expected since these pollutants are known as the O₃ precursors. Besides that, O₃ concentration and its precursors show a positive significant correlation with all meteorological factors except for relative humidity.