Determinants of personal exposure to fine particulate matter (PM2.5) in adult subjects in Hong Kong

Xiao Cui Chen, Tony J. Ward, Jun Ji Cao, Shuncheng Lee, Judith C. Chow, Gabriel N.C. Lau, Steve H.L. Yim, Kin Fai Ho

Research output: Journal article publicationJournal articleAcademic researchpeer-review

44 Citations (Scopus)


Personal monitoring for fine particulate matter (PM 2.5) was conducted for adults (48 subjects, 18–63 years of age) in Hong Kong during the summer and winter of 2014–2015. All filters were analyzed for PM 2.5 mass and constituents (including carbonaceous aerosols, water-soluble ions, and elements). We found that season (p = 0.02) and occupation (p < 0.001) were significant factors affecting the strength of the personal-ambient PM 2.5 associations. We applied mixed-effects models to investigate the determinants of personal exposure to PM 2.5 mass and constituents, along with within- and between-individual variance components. Ambient PM 2.5 was the dominant predictor of (R 2 = 0.12–0.59, p < 0.01) and the largest contributor (>37.3%) to personal exposures for PM 2.5 mass and most components. For all subjects, a one-unit (2.72 μg/m 3) increase in ambient PM 2.5 was associated with a 0.75 μg/m 3 (95% CI: 0.59–0.94 μg/m 3) increase in personal PM 2.5 exposure. The adjusted mixed-effects models included information extracted from individual's activity diaries as covariates. The results showed that season, occupation, time indoors at home, in transit, and cleaning were significant determinants for PM 2.5 components in personal exposure (R 2 β = 0.06–0.63, p < 0.05), contributing to 3.0–70.4% of the variability. For one-hour extra time spent at home, in transit, and cleaning an average increase of 1.7–3.6% (ammonium, sulfate, nitrate, sulfur), 2.7–12.3% (elemental carbon, ammonium, titanium, iron), and 8.7–19.4% (ammonium, magnesium ions, vanadium) in components of personal PM 2.5 were observed, respectively. In this research, the within-individual variance component dominated the total variability for all investigated exposure data except PM 2.5 and EC. Results from this study indicate that performing long-term personal monitoring is needed for examining the associations of mass and constituents of personal PM 2.5 with health outcomes in epidemiological studies by describing the impacts of individual-specific data on personal exposures.

Original languageEnglish
Pages (from-to)1165-1177
Number of pages13
JournalScience of the Total Environment
Publication statusPublished - 1 Jul 2018


  • Fine particulate matter
  • Mixed-effects model
  • Particulate constituents
  • Personal exposure
  • Time-activity diaries

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution


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