Methylene blue active substances (Mbas) and linear alkylbenzene sulphonates (las) in urban and suburban atmospheric aerosol

Surfactant is one of the pollutants derived from atmospheric aerosol that can adversely affect the human health and environment. This study aims to characterize the level of anionic surfactants as Methylene Blue Active Substances (MBAS) and Linear Alkylbenzene Sulphonates (LAS) extracted from atmospheric aerosol from urban (Kuala Lumpur) and suburban (Bangi) area of Malaysia. For aerosol sampling, a high volume sampler (HVAS) with a cascade impactor was used to collect atmospheric aerosol sample according to particle size (coarse mode (\u3e1.5 µm) and fine mode (\u3c1.5 µm)). The level of MBAS was determined using UV-Vis Spectrophotometer based on colorimetric method, while the concentration of LAS was determined using High-Performance Liquid Chromatography (HPLC). Results showed that the composition of MBAS and LAS for both sampling stations was dominated by fine mode particles compared to coarse mode with a significant difference (p \u3c 0.05). Kuala Lumpur showed higher concentration of MBAS (81.69 ± 13.01 ng m-3) compared to LAS (2.96 ± 1.22 ng m-3), while Bangi recorded lower level of both MBAS and LAS (44.58 ± 10.05 ng m-3, 2.48 ± 1.28 ng m-3), respectively. In terms of monsoonal effect, the highest level of surfactants as MBAS and LAS in both stations was recorded during southwest monsoon. A positive correlation was detected between MBAS and LAS. However, it was not significantly correlated (p \u3e 0.05). From this study, it can be concluded that MBAS concentrations in urban and suburban atmosphere are not fully affected by commercial LAS. Majority of MBAS may be presented from other natural activities and anthropogenic sources such as motor vehicle emission, combustion of biomass, and the earth\u27s crust. The management of surfactants’ use needs to be reconsidered to enhance a better atmosphere especially in urban and suburban area in the future