10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Assessment of Personal Exposure to Particulate Emissions in Urban Microenvironments
Jie Rui Ngoh, Thi Minh Phuong Tran, RAJASEKHAR BALASUBRAMANIAN, National University of Singapore
Abstract Number: 275 Working Group: Aerosol Exposure
Abstract Fine particles suspended in air (PM2.5) pose a threat to public health due to their ability to penetrate deep into the respiratory tract and migrate into the bloodstream. As a result, finding the sources of these particles and controlling their emissions are a top priority in many countries. Fixed air quality monitoring stations, equipped with expensive and bulky instruments, are widely used to measure PM2.5. However, these instruments have limitations because of their fixed positions and do not provide spatially representative PM2.5 readings. Furthermore, the PM2.5 concentrations provided by a single monitoring site may not accurately represent the particle concentrations around people distributed in its vicinity, who may be concerned about the health effects of PM exposure. Mobile and cost-effective PM2.5 sensors been developed in recent years to overcome this problem and to provide realistic data for human exposure assessment and urban air quality improvement.
We carried out a pilot study to assess personal exposure to mass concentration of PM2.5, sub-micron particle number concentration, Np, and equivalent Black Carbon, eBC, in diverse outdoor and indoor microenvironments (MEs) in Singapore, a densely populated country. A GPS receiver was used to track movement and exposure of individuals across the MEs. The novelty of this approach is that exposure measurements were taken across the full heterogeneity of places visited and activities conducted to gain as much insight as possible into an individual's total exposure. This is important as individuals are constantly on the move and follow their own activity patterns, which determine their individual exposure. Exposure to PM2.5, Np, and eBC varied considerably across the MEs because of changes in the particulate emissions from local sources in the immediate vicinity of MEs. Personal exposures to PM2.5 based on the data obtained from portable sensors were much higher those from fixed air quality monitoring stations. Mobile sensing could thus provide local environmental protection agencies with a comprehensive map of PM concentrations, at specific locations and at specific times, which allows for formulation of effective strategies to reduce PM emissions at the city scale.