For ultrafine particle (UFP) exposure assessment, there is no standardized sampling method. One of research agenda is background measurement strategy. It is required to distinguish the particles between emission sources and background at the workplace. There are three ways for background concentration measurement. The first is near-field method for real-time measurement in terms of the time such as working, meal and off-duty. The second is far-field method for measuring at different places. The third is the characterization of UFP by electron microscope or chemical analysis of samples [[i]]. The study aims to compare the background measurement methods.
[i] Ham S, Yoon C, Lee E, Lee K, Park D, Chung E, Kim P, Lee B. Task-based exposure assessment of nanoparticles in the workplace. J of Nanopart. Res. 2012; 14(9), pp1126-1143