Fine particulate matter in the tropical environment: monsoonal effects, source apportionment, and health risk assessment

Abstract

The health implications of PM 2.5 in the tropical region of Southeast Asia (SEA) are significant as PM 2.5 can pose serious health concerns. PM 2.5 concentration and sources here are strongly influenced by changes in the monsoon regime from the south-west quadrant to the north-east quadrant in the region. In this work, PM 2.5 samples were collected at a semi-urban area using a high-volume air sampler at different seasons on 24 h basis. Analysis of trace elements and water-soluble ions was performed using inductively coupled plasma mass spectroscopy (ICP-MS) and ion chromatography (IC), respectively. Apportionment analysis of PM 2.5 was carried out using the United States Environmental Protection Agency (US EPA) positive matrix factorization (PMF) 5.0 and a mass closure model. We quantitatively characterized the health risks posed to human populations through the inhalation of selected heavy metals in PM 2.5 . 48 % of the samples collected exceeded the World Health Organization (WHO) 24 h PM 2.5 guideline but only 19 % of the samples exceeded 24 h US EPA National Ambient Air Quality Standard (NAAQS). The PM 2.5 concentration was slightly higher during the north-east monsoon compared to south-west monsoon. The main trace metals identified were As, Pb, Cd, Ni, Mn, V, and Cr while the main ions were SO 2− 4 , NO − 3 , NH + 4 , and Na. The mass closure model identified four major sources of PM 2.5 that account for 55 % of total mass balance. The four sources are mineral matter (MIN) (35 %), secondary inorganic aerosol (SIA) (11 %), sea salt (SS) (7 %), and trace elements (TE) (2 %). PMF 5.0 elucidated five potential sources: motor vehicle emissions coupled with biomass burning (31 %) were the most dominant, followed by marine/sulfate aerosol (20 %), coal burning (19 %), nitrate aerosol (17 %), and mineral/road dust (13 %). The hazard quotient (HQ) for four selected metals (Pb, As, Cd, and Ni) in PM 2.5 mass was highest in PM 2.5 mass from the coal burning source and least in PM 2.5 mass originating from the mineral/road dust source. The main carcinogenic heavy metal of concern to health at the current location was As; the other heavy metals (Ni, Pb, and Cd) did not pose a significant cancer risk in PM 2.5 mass concentration. Overall, the associated lifetime cancer risk posed by the exposure of hazardous metals in PM 2.5 is 3-4 per 1 000 000 people at this location. Published by CopernicusPublications on behalf of the European Geosciences Union. 598 M. F. Khan et al.: Fine particulate matter in the tropical environment Atmos. Chem. Phys., 16, 597-617, 2016 www.atmos-chem-phys.net/16/597/2016/

High-resolution sampling and analysis of ambient particulate matter in the Pearl River Delta region of southern China: source apportionment and health risk implications

“…For the carcinogenic risks, industrial coal combustion was found to be the largest contributor, followed by biomass burning sources. Similar findings were reported by Khan et al (2016) in the tropical environment in Malaysia. Secondary inorganic aerosols contributed approximately 25 % of the PM 2.5 mass, but they posed little carcinogenic risk.…”

“…Moreover, airborne particles and associated trace elements originate from various emission sources, such as motor vehicles, metallurgical industry, coal burning and soil dust, and could be emitted in a broad size range. Studies suggest that some particle sources are more harmful than others and recommend that controlling some of the specific sources of PM could be a more effective way for protecting public health (Bell et al, 2014;Khan et al, 2016). Airborne particle health risk assessment is increasingly dependent on the source apportionment of PM using chemical component data.…”

High-resolution sampling and analysis of ambient particulate matter in the Pearl River Delta region of Southern China: source apportionment and health risk implications

“…For the carcinogenic risks, industrial coal 5 combustion was found the largest contributor, followed by biomass burning source. Similar findings were reported by Khan et al (2016) in the a tropical environment in Malaysia. Secondary inorganic aerosols contributed approximately 25% of the PM 2.5 mass, but they posed little carcinogenic risk.…”

“…protecting public health (Bell et al, 2014;Khan et al, 2016). Airborne particle health risk assessment is increasingly depended on the source apportionment of PM using chemical component data.…”

Effects of Seasonality and Transport Route on Chemical Characteristics of PM2.5 and PM2.5-10 in the East Asian Pacific Rim Region

“…These studies showed high As, Pb, and Zn concentrations in most Southeast Asia. The sources of As, Pb, and Zn may originate from coal-fired power, lead related industries and vehicle (Santoso et al, 2011;Wimolwattanapun et al, 2011;Khan et al, 2016).…”