Spatial distribution of fine and coarse particulate matter during a southwest monsoon in Peninsular Malaysia.

This study aimed to determine the spatial distribution of PM and PM collected in four regions (North, Central, South and East Coast) of Peninsular Malaysia during the southwest monsoon. Concurrent measurements of PM and PM were performed using a high volume sampler (HVS) for 24 h (August to September 2018) collecting a total of 104 samples. All samples were then analysed for water soluble inorganic ions (WSII) using ion chromatography, trace metals using inductively coupled plasma-mass spectroscopy (ICP-MS) and polycyclic aromatic hydrocarbon (PAHs) using gas chromatography-mass spectroscopy (GC-MS). The results showed that the highest average PM concentration during the sampling campaign was in the North region (33.2 ± 5.3 μg m) while for PM the highest was in the Central region (38.6 ± 7.70 μg m). WSII recorded contributions of 22% for PM and 20% for PM mass, with SO the most abundant species with average concentrations of 1.83 ± 0.42 μg m (PM) and 2.19 ± 0.27 μg m (PM). Using a Positive Matrix Factorization (PMF) model, soil fertilizer (23%) was identified as the major source of PM while industrial activity (25%) was identified as the major source of PM. Overall, the studied metals had hazard quotients (HQ) value of <1 indicating a very low risk of non-carcinogenic elements while the highest excess lifetime cancer risk (ELCR) was recorded for Cr VI in the South region with values of 8.4E-06 (PM) and 6.6E-05 (PM). The incremental lifetime cancer risk (ILCR) calculated from the PAH concentrations was within the acceptable range for all regions.