Fine particulate matter associated with monsoonal effect and   the responses of biomass fire hotspots in the tropical environment

Abstract. The health implications of PM2.5 in tropical regions of Southeast Asia are significant as PM2.5 can pose serious health concerns. PM2.5 is strongly influenced by the monsoon. We quantitatively characterize the health risks posed to human populations by selected heavy metals in PM2.5. Monsoonal effects as well as factors influencing the sources of PM2.5 were also determined. Apportionment analysis of PM2.5 was undertaken using US EPA positive matrix factorization (PMF) 5.0 and a mass closure model. Overall, 48 % of the samples exceeded the World Health Organization (WHO) 24 h guideline. The mass closure model identified four sources of PM2.5: (a) mineral matter (MIN) (35 %), (b) secondary inorganic aerosol (SIA) (11 %), (c) sea salt (SS) (7 %), (d) trace elements (TE) (2 %) and (e) undefined (UD) (45 %). PMF 5.0 identified five potential sources and motor vehicle emissions and biomass burning were dominant followed by marine and sulfate aerosol, coal burning, nitrate aerosol, and mineral and road dust. The non-carcinogenic risk level for four selected metals (Pb, As, Cd and Ni) in PM2.5 and in the identified major sources by PMF > 5.0, with respect to inhalation follows the order of PM2.5 > coal burning > motor vehicle emissions/biomass burning > mineral/road dust. The lifetime cancer risk follows the order of As > Ni > Pb > Cd for mineral/road dust, coal burning and overall of PM2.5 concentration and As > Pb > Ni > Cd for motor vehicle/biomass burning. Overall, the associated cancer risk posed by the exposure of toxic metals in PM2.5 is three to four in 1 000 000 people in this location.

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Optical source apportionment and radiative forcing of light-absorbing carbonaceous aerosol at a tropical marine monsoon climate zone: the importance of ship emissions

10.5194/acp-2020-474 ◽

2020 ◽

Author(s):

Qiyuan Wang ◽

Huikun Liu ◽

Ping Wang ◽

Wenting Dai ◽

Ting Zhang ◽

...

Keyword(s):

Optical Properties ◽

Biomass Burning ◽

Radiative Forcing ◽

Vehicle Emissions ◽

Motor Vehicle ◽

Carbonaceous Aerosol ◽

Monsoon Climate ◽

Ship Emissions ◽

Climate Zone ◽

Motor Vehicle Emissions

Abstract. Source-specific optical properties of light-absorbing carbonaceous (LAC) aerosol are poorly understood owing to its various sources in the atmosphere. Here, a receptor model coupling multi-wavelength absorption with chemical species was utilized to explore the source-specific LAC optical properties at a tropical marine monsoon climate zone. Results showed that biomass burning contributed the largest to LAC absorption on average, but ship emissions became the dominant contributor (44–45 %) when the air masses originated from the South China Sea. The source-specific absorption Ångström exponent indicates that black carbon (BC) was the dominant LAC aerosol in ship and motor vehicle emissions while there was also brown carbon (BrC) existed in biomass-burning emissions. The source-specific mass absorption cross section (MAC) showed that BC from ship emissions had a stronger light-absorbing capacity than biomass burning and motor vehicle emissions. The BrC MAC derived from biomass burning was smaller than BC MAC and highly depended on wavelengths. Radiative effect assessment indicates a comparable atmospheric forcing and heating capacity of LAC aerosol from biomass burning and ship emissions. Our study provides insights into the optical properties of LAC aerosol from various sources and can improve our understanding of the LAC radiative effects caused by ship emissions.

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Quantifying Air Pollutant Variations during COVID-19 Lockdown in a Capital City in Northwest China

Atmosphere ◽

10.3390/atmos12060788 ◽

2021 ◽

Vol 12 (6) ◽

pp. 788

Author(s):

Rong Feng ◽

Hongmei Xu ◽

Zexuan Wang ◽

Yunxuan Gu ◽

Zhe Liu ◽

...

Keyword(s):

Air Pollution ◽

Air Quality ◽

Rural Areas ◽

Vehicle Emissions ◽

Motor Vehicle ◽

Northwest China ◽

Air Pollutant ◽

Capital City ◽

Air Pollution Control ◽

Motor Vehicle Emissions

In the context of the outbreak of coronavirus disease 2019 (COVID-19), strict lockdown policies were implemented to control nonessential human activities in Xi’an, northwest China, which greatly limited the spread of the pandemic and affected air quality. Compared with pre-lockdown, the air quality index and concentrations of PM2.5, PM10, SO2, and CO during the lockdown reduced, but the reductions were not very significant. NO2 levels exhibited the largest decrease (52%) during lockdown, owing to the remarkable decreased motor vehicle emissions. The highest K+ and lowest Ca2+ concentrations in PM2.5 samples could be attributed to the increase in household biomass fuel consumption in suburbs and rural areas around Xi’an and the decrease in human physical activities in Xi’an (e.g., human travel, vehicle emissions, construction activities), respectively, during the lockdown period. Secondary chemical reactions in the atmosphere increased in the lockdown period, as evidenced by the increased O3 level (increased by 160%) and OC/EC ratios in PM2.5 (increased by 26%), compared with pre-lockdown levels. The results, based on a natural experiment in this study, can be used as a reference for studying the formation and source of air pollution in Xi’an and provide evidence for establishing future long-term air pollution control policies.

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Impact of sulfur-in-gasoline on motor vehicle emissions in the metropolitan area of Mexico City☆

Fuel ◽

10.1016/s0016-2361(03)00118-2 ◽

2003 ◽

Vol 82 (13) ◽

pp. 1605-1612 ◽

Cited By ~ 12

Author(s):

I Schifter ◽

L Dı́az ◽

M Vera ◽

E Guzmán ◽

E López-Salinas

Keyword(s):

Mexico City ◽

Metropolitan Area ◽

Vehicle Emissions ◽

Motor Vehicle ◽

Motor Vehicle Emissions

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Motor vehicle emissions and fuel consumption modelling

Transportation Research Part A General ◽

10.1016/0191-2607(79)90003-7 ◽

1979 ◽

Vol 13 (6) ◽

pp. 395-406 ◽

Cited By ~ 12

Author(s):

J.H. Kent ◽

N.R. Mudford

Keyword(s):

Fuel Consumption ◽

Vehicle Emissions ◽

Motor Vehicle ◽

Motor Vehicle Emissions

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Effect of motor vehicle emissions on air quality of green urban community

Progress in Civil, Architectural and Hydraulic Engineering IV ◽

10.1201/b19383-249 ◽

2015 ◽

pp. 1215-1218

Author(s):

S Zhao ◽

Q Li ◽

X You

Keyword(s):

Air Quality ◽

Vehicle Emissions ◽

Motor Vehicle ◽

Urban Community ◽

Motor Vehicle Emissions

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

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-597-2016 ◽

2016 ◽

Vol 16 (2) ◽

pp. 597-617 ◽

Cited By ~ 75

Author(s):

M. F. Khan ◽

M. T. Latif ◽

W. H. Saw ◽

N. Amil ◽

M. S. M. Nadzir ◽

...

Keyword(s):

Heavy Metals ◽

Trace Elements ◽

Cancer Risk ◽

Road Dust ◽

Closure Model ◽

North East ◽

The North ◽

South West ◽

Us Epa ◽

Pm2.5 Concentration

Abstract. The health implications of PM2.5 in the tropical region of Southeast Asia (SEA) are significant as PM2.5 can pose serious health concerns. PM2.5 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, PM2.5 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 PM2.5 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 PM2.5. 48 % of the samples collected exceeded the World Health Organization (WHO) 24 h PM2.5 guideline but only 19 % of the samples exceeded 24 h US EPA National Ambient Air Quality Standard (NAAQS). The PM2.5 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 SO42−, NO3−, NH4+, and Na. The mass closure model identified four major sources of PM2.5 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 PM2.5 mass was highest in PM2.5 mass from the coal burning source and least in PM2.5 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 PM2.5 mass concentration. Overall, the associated lifetime cancer risk posed by the exposure of hazardous metals in PM2.5 is 3–4 per 1 000 000 people at this location.

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