Measurement report: Characterization and source apportionment of coarse particulate matter in Hong Kong: Insights into the constituents of unidentified mass and source origins in a coastal city in southern China

Abstract. Coarse particulate matter (i.e., PM with aerodynamic diameter between 2.5 and 10 micrometers or PMcoarse) has been increasingly recognized of its importance in PM10 regulation because of its growing proportion in PM10 and the accumulative evidence for its adverse health impact. In this work, we present comprehensive PMcoarse speciation results obtained through a one-year long (January 2020–February 2021) joint PM10 and PM2.5 chemical speciation study in Hong Kong, a coastal and highly urbanized city in southern China. The annual average concentration of PMcoarse is 14.9 ± 8.6 μg m–3 (±standard deviation), accounting for 45 % of PM10 (32.9 ± 18.5 μg m–3). The measured chemical components explain ~75 % of the PMcoarse mass. The unexplained part is contributed by unmeasured geological components and residue liquid water content, supported by analyses by positive matrix factorization (PMF) and the thermodynamic equilibrium model ISORROPIA II. The PMcoarse mass is apportioned to four sources resolved by PMF, namely soil dust, copper-rich dust, fresh sea salt, and an aged sea salt factor containing secondary inorganic aerosols (mostly nitrate). Back-trajectory cluster analysis reveals significant variations in source contributions with the air mass origin. Under the influence of marine air mass, PMcoarse is the lowest (average = 8.0 μg m–3) and sea salt is the largest contributor (47 %), followed by the two dust factors (38 % in total). When the site receives air mass from the northern continental region, PMcoarse increased substantially to 21.2 μg m–3, with the two dust factors contributing 90 % of the aerosol mass. The potential dust source areas are mapped using the Concentration-Weighted Trajectory technique, showing either the Greater Bay Area or the greater part of southern China as the origin of fugitive dust emissions leading to elevated ambient PMcoarse loadings in Hong Kong. This study, first of this kind in our region, provides highly relevant guidance to other locations with similar monitoring needs. Additionally, the study findings point to the needs for further research on the sources, transport, aerosol processes, and health effects of PMcoarse.

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Supplementary material to "Measurement report: Characterization and source apportionment of coarse particulate matter in Hong Kong: Insights into the constituents of unidentified mass and source origins in a coastal city in southern China"

10.5194/acp-2021-1030-supplement ◽

2021 ◽

Author(s):

Yee Ka Wong ◽

Kin Man Liu ◽

Claisen Yeung ◽

Kenneth K. M. Leung ◽

Jian Zhen Yu

Keyword(s):

Hong Kong ◽

Particulate Matter ◽

Source Apportionment ◽

Southern China ◽

Coastal City ◽

Coarse Particulate Matter ◽

Supplementary Material

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Properties of aerosols and formation mechanisms over southern China during the monsoon season

10.5194/acp-2016-390 ◽

2016 ◽

Author(s):

Weihua Chen ◽

Xuemei Wang ◽

Jason Blake Cohen ◽

Shengzhen Zhou ◽

Zhisheng Zhang ◽

...

Keyword(s):

Aqueous Phase ◽

Atmospheric Aerosols ◽

Transport Model ◽

Atmospheric Transport ◽

Southern China ◽

Monsoon Season ◽

Sea Salt ◽

Urban Site ◽

Chemical Components ◽

Formation Mechanisms

Abstract. Measurements of size-resolved aerosols from 0.25 to 18 μm were conducted at three sites (urban, suburban and background sites) and used in tandem with an atmospheric transport model to study the size distribution and formation of atmospheric aerosols in southern China during the monsoon season (May–June) in 2010. The mass distribution showed the majority of chemical components were found in the smaller size bins (< 2.5 μm). Sulfate, was found to be strongly correlated with aerosol water, and anti-correlated with atmospheric SO2, hinting at aqueous-phase reactions being the main formation pathway. Nitrate was the only major species that showed a bi-modal distribution at the urban site, and was dominated by the coarse mode in the other two sites, suggesting that an important component of nitrate formation is chloride depletion of sea salt transported from the South China Sea. In addition to these aqueous-phase reactions and interactions with sea salt aerosols, new particle formation, chemical aging, and long-range transport from upwind urban or biomass burning regions were also found to be important in at least some of the sights on some of the days. This work therefore summarizes the different mechanisms that significantly impact the aerosol chemical composition during the Monsoon over southern China.

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Effects of Coarse Particulate Matter on Emergency Hospital Admissions for Respiratory Diseases: A Time-Series Analysis in Hong Kong

Environmental Health Perspectives ◽

10.1289/ehp.1104002 ◽

2012 ◽

Vol 120 (4) ◽

pp. 572-576 ◽

Cited By ~ 110

Author(s):

Hong Qiu ◽

Ignatius Tak-sun Yu ◽

Linwei Tian ◽

Xiaorong Wang ◽

Lap Ah Tse ◽

...

Keyword(s):

Time Series ◽

Hong Kong ◽

Particulate Matter ◽

Time Series Analysis ◽

Respiratory Diseases ◽

Hospital Admissions ◽

Emergency Hospital ◽

Series Analysis ◽

Emergency Hospital Admissions ◽

Coarse Particulate Matter

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Coarse particulate matter associated with increased risk of emergency hospital admissions for pneumonia in Hong Kong

Thorax ◽

10.1136/thoraxjnl-2014-205429 ◽

2014 ◽

Vol 69 (11) ◽

pp. 1027-1033 ◽

Cited By ~ 52

Author(s):

Hong Qiu ◽

Lin Wei Tian ◽

Vivian C Pun ◽

Kin-fai Ho ◽

Tze Wai Wong ◽

...

Keyword(s):

Hong Kong ◽

Particulate Matter ◽

Hospital Admissions ◽

Emergency Hospital ◽

Emergency Hospital Admissions ◽

Increased Risk ◽

Coarse Particulate Matter

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Correlation of black carbon aerosol and carbon monoxide concentrations measured in the high-altitude environment of Mt. Huangshan, Eastern China

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-4447-2011 ◽

2011 ◽

Vol 11 (2) ◽

pp. 4447-4485 ◽

Cited By ~ 2

Author(s):

X. L. Pan ◽

Y. Kanaya ◽

Z. F. Wang ◽

Y. Liu ◽

P. Pochanart ◽

...

Keyword(s):

Carbon Monoxide ◽

High Altitude ◽

Black Carbon ◽

Urban Areas ◽

Southern China ◽

Eastern China ◽

Back Trajectory ◽

Strong Positive Correlation ◽

Air Mass ◽

Co Concentration

Abstract. Understanding the relationship between black carbon (BC) and carbon monoxide (CO) will help improve BC emission inventories and the evaluation of global/regional climate forcing effects. In the present work, the BC (PM1) and CO mixing ratio was continuously measured at a~high-altitude background station on the summit of Mt Huangshan between 2006 and 2009. Annual mean BC concentration was 654.6 ± 633.4 ng m−3 with maxima in spring and autumn, when biomass was burned over a large area in Eastern China. The yearly averaged CO concentration was 446.4 ± 167.6 ppbv, and the increase in the CO concentration was greatest in the cold season, implying that the large-scale domestic coal/biofuel combustion for heating has an effect. The BC–CO relationship was found to have different seasonal features but strong positive correlation (R > 0.8). Back trajectory cluster analysis showed that the ΔBC/ΔCO ratio of plumes from the Yangtze River Delta region was 6.58 ± 0.96 ng m−3 ppbv−1, which is consistent with result from INTEX-B emission inventory. The ΔBC/ΔCO ratios for air masses from Northern, Central Eastern and Southern China were 5.2 ± 0.63, 5.65 ± 0.58 and 5.21 ± 0.93 ng m−3 ppbv−1, respectively. Over the whole observation period, the ΔBC/ΔCO ratio had unimodal diurnal variations and had a maximum during the day (09:00–17:00 LST) and minimum at night (21:00–04:00 LST) in spring, summer, autumn and winter, indicating the effects of the intrusion of clean air mass from the high troposphere. The case study combined with measurements of urban PM10 concentrations and satellite observations demonstrated that the ΔBC/ΔCO ratio for a plume of burning biomass was 12.4 ng m−3 ppbv−1 and that for urban plumes in Eastern China was 5.3 ± 0.53 ng m−3 ppbv−1. Transportation and industry were deemed as controlling factors of the BC–CO relationship and major contributions to atmospheric BC and CO loadings in urban areas. The loss of BC during transportation was also investigated on the basis of the ΔBC/ΔCO–RH relationship along air mass pathways, and the results showed that 30–50% BC was lost when air mass traveled under higher RH conditions (>60%) for 2 days.

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