title: Detection of Carbonaceous Aerosols Released in CNT Workplaces Using an Aethalometer.
abstract: OBJECTIVE
  Black carbon (BC) originating from various combustion sources has been extensively surveyed to characterize the effects of BC on global warming and human health, and many online monitors are available. In this study, BC was considered as a surrogate for carbon-based nanomaterials in an occupational health study.
  
  
  METHODS
  Specifically, BC concentrations were monitored continuously with an aethalometer for 24h at four carbon nanotube (CNT) workplaces located in rural, urban, and industrial areas, which had different background air pollution levels. Average BC concentrations for both nonworking (background) and working periods were compared with the recommended exposure limit (REL) of 1 μg m(-3) for elemental carbon that was suggested by the National Institute for Occupational Safety and Health (NIOSH).
  
  
  RESULTS
  Diurnal variation of BC concentrations indicated that BC measurements corresponded well with carbonaceous aerosols such as vehicle exhaust particles and CNT aerosols. In the rural CNT workplace, the average background BC concentration (0.36 μg m(-3)) was lower than the REL, but the BC concentration without background correction was higher than the REL during manufacturing hours. In this case, BC measurement is useful to estimate CNT exposure for comparison with the REL. Conversely, in the urban and industrial CNT workplaces, average background BC concentrations (2.05, 1.82, and 2.64 μg m(-3)) were well above the REL, and during working hours, BC concentrations were substantially higher than the background level at workplace C; however, BC concentrations showed no difference from the background levels at workplaces B and D. In these cases (B and D), it is hard to determine CNT exposure because of the substantial environmental exposures.
  
  
  CONCLUSIONS
  Most of the urban ambient BC concentrations were above the REL. Therefore, further analysis and test methods for carbonaceous aerosols need to be developed so that the exposure assessment can be easily carried out at CNT workplaces with high background BC levels such as in urban and industrial areas.
authors.affiliation: 1.Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology, 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea; 2.Green School (Graduate School of Energy and Environment), Korea University, 145 Anam-ro Seongbuk-gu, Seoul 02841, Republic of Korea;
authors.forename: Jong Bum
authors.initials: JB
authors.lastname: Kim
authors.affiliation: 3.Dong-il Shimadzu Corporation, No 1105, Acehighend Tower 3-cha, 145, Gasan digital 1-ro, Geumcheon-gu, Seoul 08506, Republic of Korea;
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Kim
authors.affiliation: 2.Green School (Graduate School of Energy and Environment), Korea University, 145 Anam-ro Seongbuk-gu, Seoul 02841, Republic of Korea; 4.Department of Earth and Environmental Sciences, Korea University, 145 Anam-ro Seongbuk-gu, Seoul 02841, Republic of Korea.
authors.forename: Seong-Taek
authors.initials: ST
authors.lastname: Yun
authors.affiliation: 1.Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology, 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea; 2.Green School (Graduate School of Energy and Environment), Korea University, 145 Anam-ro Seongbuk-gu, Seoul 02841, Republic of Korea; gnbae@kist.re.kr.
authors.forename: Gwi-Nam
authors.initials: GN
authors.lastname: Bae
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000395:Air Pollutants, Occupational / Q000009:adverse effects / Q000032:analysis; D002244:Carbon / Q000032:analysis*; D004784:Environmental Monitoring; D006801:Humans; D037742:Nanotubes, Carbon / Q000032:analysis*; D016273:Occupational Exposure; D010316:Particle Size; D017132:Workplace
chemical_list: D000336:Aerosols; D000395:Air Pollutants, Occupational; D037742:Nanotubes, Carbon; D002244:Carbon
keywords: black carbon; carbon nanotube; elemental carbon; exposure assessment; nanomaterial; workplace