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A comprehensive assessment of fine particulate matter (PM2.5) compositions during the Southeast Asia dry season is presented. Samples of PM2.5 were collected between 24 June and 14 September 2014 using a high‐volume sampler. Water‐soluble ions, trace species, rare earth elements, and a range of elemental carbon (EC) and organic carbon were analyzed. The characterization and source apportionment of PM2.5 were investigated. The results showed that the 24 h PM2.5 concentration ranged from 6.64 to 68.2 µg m−3. Meteorological driving factors strongly governed the diurnal concentration of aerosol, while the traffic in the morning and evening rush hours coincided with higher levels of CO and NO2. The correlation analysis for non sea‐salt K+‐EC showed that EC is potentially associated with biomass burning events, while the formation of secondary organic carbon had a moderate association with motor vehicle emissions. Positive matrix factorization (PMF) version 5.0 identified the sources of PM2.5: (i) biomass burning coupled with sea salt [I] (7%), (ii) aged sea salt and mixed industrial emissions (5%), (iii) road dust and fuel oil combustion (7%), (iv) coal‐fired combustion (25%), (v) mineral dust (8%), (vi) secondary inorganic aerosol (SIA) coupled with F− (15%), and (vii) motor vehicle emissions coupled with sea salt [II] (24%). Motor vehicle emissions, SIA, and coal‐fired power plant are the predominant sources contributing to PM2.5. The response of the potential source contribution function and Hybrid Single‐Particle Lagrangian Integrated Trajectory backward trajectory model suggest that the outline of source regions were consistent to the sources by PMF 5.0.

This study aims to determine the concentrations of surfactants in the surface microlayer (SML), subsurface water (SSW) and fine mode aerosol (diameter size < 1.5 μm) at different coastal stations in Peninsular Malaysia. The concentrations of anionic and cationic surfactants were determined through colorimetric methods as methylene blue active substances (MBAS) and disulphine blue active substances (DBAS), respectively. Water-soluble ions, for the determination of fine mode aerosol sources, were determined using ion chromatography (IC) for anions (SO, NO, Cl and F) and cations (Na, K, Ca and Mg). Principal component analysis (PCA), combined with multiple linear regression (MLR), was used to identify the possible sources of surfactants in fine aerosol. The results showed the concentrations of surfactants as MBAS and DBAS in the SML ranged between 0.23 ± 0.03 and 0.35 ± 0.01 μmol L and between 0.21 ± 0.02 and 0.29 ± 0.01 μmol L, respectively. The enrichment factors (Efs) ratios between MBAS and DBAS in the SML and SSW ranged between 1.04 ± 0.01 and 1.32 ± 0.04, respectively. The station that is located near to tourism and industrial activities recorded the highest concentrations of surfactants in SML and SSW. The concentrations of surfactants in fine aerosol ranged between 62.29 and 106.57 pmol m. The three possible sources of fine aerosol during the northeast monsoon were aged sea spray/biomass burning (which accounted for 69% of the atmospheric aerosol), nitrate/mineral dust (23%) and sulphate/fresh sea salt (8%). During the southwest monsoon, the three main sources of atmospheric aerosol were biomass burning (71%), secondary inorganic aerosol (23%) and sea spray (6%). This study suggests anthropogenic sources are main contributors to the concentrations of surfactants in SML, SSW and fine aerosols.

Problem statement:The air quality study of PPR Taman Wahyu II, Selayang, Selangor was a residential project that was built on the former landfill site. The landfill site will produce landfill gases which can influence the air quality level in and outside the building. Approach: This air quality study also involving PPR Intan Baiduri, Batu Caves, Selangor as a control building. The air quality parameters chosen were physical, chemical and biological. Instruments used were HVS, Biogas Analyzer, Aeroqual, MultiRAE, ICP-MS, NMAM 7303 and gravimetric method. Gilian High Volume Air Sampler was used to measure heavy metal parameters that were conducted for 8 h, Personal Sampling Pump to measure total suspended particulates for 8 h, MultiRAE for H 2 S and CH 4 gas, Aeroqual for CO 2 gas, Multilog for CO gas and a Tedlar bag for O 2 gas. For biological parameters, settle plate method was used and conducted for 20 min. Veloci CALC and wind probe were used to measure physical parameters. Results: In the ambient air, the mean concentration of Total Suspended Particulate (TSP), lead and cadmium were higher at an exposed location compared to the control with a reading of 0.325±0.29, 0.108±0.050 and 0.06±0.045 ng m −3 respectively. The reason was that the exposed location was a former landfill site and there were several co-founding factors. Mean concentration for chemical parameters were higher at the exposed location and all the chemical parameters were not exceeding the EPA Protocol Gas for Single Component. The mean concentration of oxygen is 20.95±0.005%, carbon dioxide 669.25±84.109 ppm and carbon monoxide 1.8±0.957 ppm. For biological parameters, mean for the colony total count also higher at the exposed location compared to control location where the mean for bacterial was 17.75±4.573cfu while for fungal, the mean is 8.0±2.828 cfu. Indoor air quality results showed that concentration means of CO 2 was 877.8±59.40 ppm, CO was 5.0±0.89 ppm and O 2 was 20.9±0.05%. The concentration means for Cd was 0.3±0.26 ng m , bacteria was 38±16 cfu and fungal was 11±7 cfu. Conclusion: The concentration mean of the gas parameters had fulfilled the guideline standard. The statistical analysis revealed that there were significant differences between CO 2 , O 2 , bacterial, fungal and TSP between research building and control building. Research also showed that there is no differentiation between former landfill ambient air and control ambient air quality.