Comparative Study of Carbon Monoxide (CO) Concentrations in Different Urban Zones of Klang Valley: Observations from Monitoring Stations by the Department of Environment (DOE), Malaysia

Purpose: The Klang Valley, Malaysia’s most densely populated and industrialised region, is experiencing significant air quality deterioration due to rapid urbanisation, industrial activities, and vehicle emissions. Methodology: This study aims to analyse the daily average trend of CO concentration at five monitoring stations operated by the Department of Environment (DOE), namely Klang, Petaling Jaya, Kajang, Shah Alam, and Cheras, from January 1st to December 31st, 2005, by using statistical scatter plot analysis. Findings: The study’s findings indicate that Petaling Jaya station has a stable trend in daily CO concentration, with a maximum of 7 ppm and a minimum of 0.5 ppm. The scatter plot shows sporadic fluctuations, but most data points are within the 1-2 ppm range, indicating a typical daily concentration level for CO in Petaling Jaya. Outliers, marked by large spikes, may be due to heavy traffic, industrial activities, or unfavourable weather conditions. Research Implication: The study highlights the need for stricter environmental regulations and urban planning strategies to manage pollution sources and emphasises the importance of continuous air quality monitoring, public health advisories, alternative transportation methods, and industrial emission controls to stabilise CO concentration and improve air quality.