Urban air quality has been deteriorating over time. Pollutant distribution levels in the urban environment may be associated with anthropogenic sources and meteorological conditions. The aim of this study is to determine the variation in concentrations of major air pollutants: carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2), sulphur dioxide (SO2) and particulate matter (PM10), with corresponding seasonal variation in a Malaysian urban environment. Eleven years of data from four selected stations, namely Klang (S1), Petaling Jaya (S2), Shah Alam (S3) and Cheras (S4), were analysed for temporal trend variations (yearly and monthly). Statistical analysis using Openair, an R package open source software, has been conducted to assess pollutants in relation to meteorological conditions. Gas concentrations showed little variation between the study sites apart from NO2, which recorded its highest concentrations at an industrial site, between 23 and 40 ppb, and is associated with industrial and vehicle emissions. Pollutants that show seasonal variations and frequently exceed the Malaysia Ambient Air Quality Standard (MAAQS) and the National Ambient Air Quality Standard (NAAQS) are O3 and PM10, predominantly related to the monsoon seasons. High levels of O3 during the northeast monsoon (January–March) are associated with high levels of the precursors of O3. The concentration of PM10 associated with tropical biomass burning during southwest monsoon. Shipping emissions and power stations are main contributors for higher level of SO2. This study shows regional and local factors contribute to the different type of air pollutant concentrations in urban environment.

中文翻译：

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马来西亚城市环境中不同季节条件下主要空气污染物的变化

随着时间的推移，城市空气质量一直在恶化。城市环境中的污染物分布水平可能与人为来源和气象条件有关。这项研究的目的是确定主要空气污染物（一氧化碳（CO），臭氧（O3），二氧化氮（NO2），二氧化硫（SO2）和颗粒物（PM10））的浓度变化以及相应的季节变化。在马来西亚的城市环境中。分析了四个选定站点（巴生（S1），八打灵再也（S2），莎阿南（S3）和蕉赖（S4））的11年数据的时间趋势变化（每年和每月）。已经使用R包开源软件Openair进行了统计分析，以评估与气象条件有关的污染物。除了二氧化氮以外，研究地点之间的气体浓度几乎没有变化，二氧化氮在工业场所记录的最高浓度为23至40 ppb，与工业和车辆排放有关。表现出季节性变化并经常超过马来西亚环境空气质量标准（MAAQS）和国家环境空气质量标准（NAAQS）的污染物为O3和PM10，主要与季风季节有关。东北季风（1月至3月）期间的高水平O3与高水平的O3前体有关。西南季风期间与热带生物质燃烧有关的PM10浓度。船舶排放物和发电站是导致SO2含量较高的主要因素。