PMID- 32286917
OWN - NLM
STAT- MEDLINE
DCOM- 20210316
LR  - 20240328
IS  - 1545-9632 (Electronic)
IS  - 1545-9624 (Print)
IS  - 1545-9624 (Linking)
VI  - 17
IP  - 6
DP  - 2020 Jun
TI  - Laboratory evaluation of a personal aethalometer for assessing airborne carbon 
      nanotube exposures.
PG  - 262-273
LID - 10.1080/15459624.2020.1740237 [doi]
AB  - Aethalometers are direct-reading instruments primarily used for measuring black 
      carbon (BC) concentrations in workplace and ambient atmospheres. Aethalometer BC 
      measurements of carbon nanotubes (CNTs) were compared to measurements made by 
      other methods when subjected to high (>30 microg/m(3)) and low (1-30 microg/m(3)) CNT 
      aerosol concentrations representing worst-case and typical workplace 
      concentrations, respectively. A laboratory-based system was developed to generate 
      carbon black, as an example of a nearly pure carbon, micron-sized aerosol, and 
      two forms of multi-walled carbon nanotubes (CNTs): small-diameter (<8 nm) and 
      large-diameter (50-80 nm). High-concentration trials were conducted during which 
      a scanning mobility particle sizer (SMPS) was used to track particle count 
      concentrations over time. Relative to the behavior of the SMPS counts over time, 
      aethalometer readings exhibited a downward drift, which is indicative of 
      aethalometer response subjected to high BC loading on the receiving filter of the 
      instrument. A post-sample mathematical method was applied that adequately 
      corrected for the drift. Low-concentration trials, during which concentration 
      drift did not occur, were conducted to test aethalometer accuracy. The average BC 
      concentration during a trial was compared to elemental carbon (EC) concentration 
      sampled with a quartz-fiber filter and quantified by NIOSH Method 5040. The CB 
      and large-diameter CNT concentrations measured with the aethalometer produced 
      slopes when regressed on EC that were not significantly different from unity, 
      whereas the small-diameter CNTs were under-sampled by the aethalometer relative 
      to EC. These results indicate that aethalometer response may drift when 
      evaluating CNT exposure scenarios, such as cleaning and powder handling, that 
      produce concentrations >30 microg/m(3). However, aethalometer accuracy remains 
      consistent over time when sampling general work zones in which CNT concentrations 
      are expected to be <30 microg/m(3). A calibration check of aethalometer response 
      relative to EC measured with Method 5040 is recommended to ensure that the 
      aethalometer readings are not under sampling CNT concentrations as occurred with 
      one of the CNTs evaluated in this study.
FAU - O'Shaughnessy, Patrick
AU  - O'Shaughnessy P
AD  - Department of Occupational and Environmental Health, College of Public Health, 
      The University of Iowa, Iowa City, Iowa.
FAU - Stoltenberg, Adrianne
AU  - Stoltenberg A
AD  - Department of Occupational and Environmental Health, College of Public Health, 
      The University of Iowa, Iowa City, Iowa.
FAU - Holder, Craig
AU  - Holder C
AD  - Department of Occupational and Environmental Health, College of Public Health, 
      The University of Iowa, Iowa City, Iowa.
FAU - Altmaier, Ralph
AU  - Altmaier R
AD  - Department of Occupational and Environmental Health, College of Public Health, 
      The University of Iowa, Iowa City, Iowa.
LA  - eng
GR  - P30 ES005605/ES/NIEHS NIH HHS/United States
GR  - T42 OH008491/OH/NIOSH CDC HHS/United States
GR  - T42OH008491/ACL/ACL HHS/United States
PT  - Evaluation Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
DEP - 20200414
PL  - England
TA  - J Occup Environ Hyg
JT  - Journal of occupational and environmental hygiene
JID - 101189458
RN  - 0 (Air Pollutants, Occupational)
RN  - 0 (Nanotubes, Carbon)
RN  - 0 (Particulate Matter)
RN  - 0 (Soot)
SB  - IM
MH  - Air Pollutants, Occupational/*analysis
MH  - Environmental Monitoring/*instrumentation
MH  - Nanotubes, Carbon/*analysis
MH  - Particulate Matter/*analysis
MH  - Soot/analysis
PMC - PMC7282999
MID - NIHMS1589163
OTO - NOTNLM
OT  - Aethalometer
OT  - carbon nanotubes
OT  - elemental carbon
EDAT- 2020/04/15 06:00
MHDA- 2021/03/17 06:00
PMCR- 2021/06/01
CRDT- 2020/04/15 06:00
PHST- 2020/04/15 06:00 [pubmed]
PHST- 2021/03/17 06:00 [medline]
PHST- 2020/04/15 06:00 [entrez]
PHST- 2021/06/01 00:00 [pmc-release]
AID - 10.1080/15459624.2020.1740237 [doi]
PST - ppublish
SO  - J Occup Environ Hyg. 2020 Jun;17(6):262-273. doi: 10.1080/15459624.2020.1740237. 
      Epub 2020 Apr 14.