title: Novel active personal nanoparticle sampler for the exposure assessment of nanoparticles in workplaces.
abstract: A novel active personal nanoparticle sampler (PENS), which enables the collection of both respirable particulate mass (RPM) and nanoparticles (NPs) simultaneously, was developed to meet the critical demand for personal sampling of engineered nanomaterials (ENMs) in workplaces. The PENS consists of a respirable cyclone and a micro-orifice impactor with the cutoff aerodynamic diameter (d(pa50)) of 4 μm and 100 nm, respectively. The micro-orifice impactor has a fixed micro-orifice plate (137 nozzles of 55 μm in the inner diameter) and a rotating, silicone oil-coated Teflon filter substrate at 1 rpm to achieve a uniform particle deposition and avoid solid particle bounce. A final filter is used after the impactor to collect the NPs. Calibration results show that the d(pa50) of the respirable cyclone and the micro-orifice impactor are 3.92 ± 0.22 μm and 101.4 ± 0.1 nm, respectively. The d(pa50) at the loaded micro-Al(2)O(3) mass of 0.36-3.18 mg is shifted to 102.9-101.2 nm, respectively, while it is shifted to 98.9-97.8 nm at the loaded nano-TiO(2) mass of 0.92-1.78 mg, respectively. That is, the shift of d(pa50) due to solid particle loading is small if the PENS is not overloaded.  Both NPs and RPM concentrations were found to agree well with those of the IOSH respirable cyclone and MOUDI. By using the present PENS, the collected samples can be further analyzed for chemical species concentrations besides gravimetric analysis to determine the actual exposure concentrations of ENMs in both RPM and NPs fractions in workplaces, which are often influenced by the background or incident pollution sources.
authors.affiliation: Institute of Environmental Engineering, National Chiao Tung University (NCTU), Hsinchu, 1001 University Road, 30010, Taiwan. cjtsai@mail.nctu.edu.tw
authors.forename: Chuen-Jinn
authors.initials: CJ
authors.lastname: Tsai
authors.forename: Chun-Nan
authors.initials: CN
authors.lastname: Liu
authors.forename: Shao-Ming
authors.initials: SM
authors.lastname: Hung
authors.forename: Sheng-Chieh
authors.initials: SC
authors.lastname: Chen
authors.forename: Shi-Nian
authors.initials: SN
authors.lastname: Uang
authors.forename: Yung-Sung
authors.initials: YS
authors.lastname: Cheng
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D053758:Nanoparticles / Q000032:analysis*; D016273:Occupational Exposure / Q000032:analysis*; D017132:Workplace
chemical_list: D000395:Air Pollutants, Occupational