Assessment on Trend Analysis of NO_X and O₃ Level in Malaysia Urban Environment

¹ Faculty of Civil Engineering & Technology, Universiti Malaysia Perlis (UniMAP), Kompleks Pusat Pengajian Jejawi 3, 02600 Arau, Perlis, Malaysia.
² National Institute for Research and Development in Environmental Protection, 294 Splaiul Independenței Blvd, 060031, Bucharest, Romania

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

Abstract

Air pollution, particularly Nitrogen Oxides (NOX) and Ozone (O3) present significant challenges to human health and environmental sustainability in Malaysian urban areas. This research addresses the critical need for analyse temporal trends of NOX and O3 pollution in six major urban cities across Peninsula Malaysia; Seberang Jaya, Tasek Ipoh, Shah Alam, Seremban, Bandaraya Melaka, and Kuala Terengganu cities (respectively monitored by CA06P, CA11A, CA20B, CA24N, CA28M, and CA44T stations). Using almost two decades (2005 to 2023) from the Department of Environment (DOE) Malaysia. The dataset contains the daily-mean air quality data of PM₁₀, SO₂, NO, NO₂, NOX, O₃, CO, relative humidity (RH), solar radiation (S), and ambient temperature (Ta). The research integrates the daily-mean descriptive statistics, monthly and annual temporal analyses, and decadal trend analyses to evaluate pollution patterns across study areas. Mann-Kendall is the test implemented in this research to identify key relationships between NOX and ground-level O₃ with other air quality parameters. The results aim to identify dominant NOX and O₃ sources, while highlight regional differences. This research supports Malaysia’s environmental strategies, offering insights for policy formulation, air quality management, and sustainable urban development.