Analysis and assessment of respirable particles in asphalt pavement recycling from perspectives of workers’ health

Shicong Mo, Yuhong Wang, Feng Xiong, Gengren Hao, Xingyu Chen, Ngai Hung Tsang

Research output: Journal article publicationJournal articleAcademic researchpeer-review


Different groups of people are exposed to respirable particles in recycling asphalt pavement materials. In evaluating the health issues of such particles posed to construction workers, existing studies mainly focus on respirable crystalline silica but rarely address the organic fractions. In this study, respirable particles in reclaimed asphalt pavement (RAP) materials were collected from different sources and analyzed to determine their morphology, elemental composition, organic content, and the content and type of polycyclic aromatic hydrocarbons (PAHs). Focus is placed on the analysis of PAHs in the particles, for which the hazards are assessed using benzo[a]pyrene toxic equivalent concentration. The respirable particles are found to contain much richer asphalt content than RAP mixtures. A variety of PAHs can be found in the particles, especially those with a large number of aromatic rings (>3). Moreover, very old RAP materials contain more PAHs, due to the oxidation reaction of the hydrocarbons in asphalt binder. Based on the analysis data and reported exposure levels to such particles in milling asphalt pavements, it is concluded that the health risks posed by such particles cannot be neglected. Mitigation measures and personal protective equipment are recommended to be used in producing and handling RAP materials.

Original languageEnglish
Article number125405
JournalConstruction and Building Materials
Publication statusPublished - 20 Dec 2021


  • Asphalt pavement resurfacing
  • Health assessment
  • Organic fractions
  • Polycyclic aromatic hydrocarbons
  • Respirable particles

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Materials Science(all)

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