Abstract
Building works include construction and demolition activities, which are common in cities across the world. Building-related activities contribute a considerable amount of the construction and demolition waste material worldwide. These activities have the potential to produce particulate matter (PM), including PM10 (≤10 μm), PM2.5 (≤2.5 μm) and PM1 (≤1 μm), and airborne ultrafine particles (≤0.1 μm). Recent studies have indicated that the rate of building works undertaken each year is growing exponentially, to meet new urban design guidelines and respond to demand from the adoption of new building technologies, which highlights the importance of measuring the amounts of particle emissions from these sources. The principles of sustainable urban development are well established, but the extent of pollution due to construction and demolition activities is still unknown. Through laboratory and field studies, this thesis aims to comprehensively investigate the release of coarse (referred to as PM2.5–10 fraction), fine (PM2.5) and ultrafine particles from various building works, assess their physicochemical properties, and estimate the associated occupational exposure risk from them to on-site workers and individuals in the close vicinity. Experiments for this thesis were carried out to measure PM and airborne ultrafine particles in the size range of (0.005–10 µm) using a fast response differential mobility spectrometer (DMS50), a tapered element oscillating micro balance (TEOM 1400), a GRIMM particle spectrometer (1.107 E) and OSIRIS (2315). Measurements were made in various locations: a controlled laboratory environment (i.e. concrete mixing, drilling, cutting), indoor field sites (i.e. building refurbishment) and at outdoor field sites (i.e. construction and demolition). Moreover, dust samples were collected simultaneously for physiochemical analyses (e.g. SEM, EDS, XPS and IBA). Several important findings were then extrapolated during the analysis. These findings indicated that ultrafine particles dominated (74-97%) the total particle number concentrations (PNCs) while the coarse particles (PM2.5-10) contributed to the majority of the total particle mass concentrations (PMCs), during the laboratory, indoor and outdoor field experiments. The highest proportion of PNCs and PMCs was found during the concrete cutting, drilling and wall chasing activities. In addition, the highest proportion of PMCs was observed in the excavator cabin during a building demolition at an outdoor field measurement site. Moreover, combining the results of SEM, EDS, XPS and IBA analysis suggested the dominance of elements such as Si, Al and S in the collected samples. The data were also used to assess the horizontal decay of the PMC through a modified box model to determine the emission factors and the occupational exposure to on-site workers and nearby individuals. The results confirmed that building-related works produce significant levels of coarse, fine and ultrafine particles, and that there is a need to limit particle emissions and reduce the occupational exposure of individuals by enforcing effective engineering controls. These findings could also be useful for the building industry to develop mitigation strategies to limit exposure to particulate matter during building works, particularly for ultrafine particles, which are currently non-existent.