Spatial Distribution of Ground Level Ozone Concentrations in Klang Valley

Abstract

Ground-level ozone (O3) is a significant air pollutant formed when sunlight reacts with nitrogen oxides (NOx) and volatile organic compounds (VOCs). It poses risks to human health, vegetation, crops, and materials. This study focuses on ground-level ozone in Klang Valley, Malaysia, using hourly average data from 2010 to 2020 acquired from the Department of Environment in Klang, Shah Alam, and Petaling Jaya. Descriptive statistics and GIS tools are employed to analyse the distribution and variations of pollutants during the study periods. The study revealed that the maximum concentration in all locations in most of the year exceeded 100 ppb, with the maximum recorded in Shah Alam at 161 ppb, while mean concentrations were 13.69 – 21.18 ppb in Klang, 17.99 – 23.88 ppb in Shah Alam, and 9.40 – 17.93 ppb in Petaling Jaya, with the daily maximum concentration still exceeding the hourly average recommended value of 90 ppb. Spatial analysis using GIS reveals the distribution of O3 concentrations is highly affected by seasonal wind direction, as high O3 concentration is observed from January to March. The study underscores the pressing issue of ozone pollution in Klang Valley and the need for mitigation strategies to improve air quality.