title: Detection of Carbon Nanotubes in Indoor Workplaces Using Elemental Impurities.
abstract: This study investigated three area sampling approaches for using metal impurities in carbon nanotubes (CNTs) to identify CNT releases in workplace environments: air concentrations (μg/m3), surface loadings (μg/cm2), and passive deposition rates (μg/m2/h). Correlations between metal impurities and CNTs were evaluated by collecting simultaneous colocated area samples for thermal-optical analysis (for CNTs) and ICP-MS analysis (for metals) in a CNT manufacturing facility. CNTs correlated strongly with Co (residual catalyst) and Ni (impurity) in floor surface loadings, and with Co in passive deposition samples. Interpretation of elemental ratios (Co/Fe) assisted in distinguishing among CNT and non-CNT sources of contamination. Stable isotopes of Pb impurities were useful for identifying aerosolized CNTs in the workplace environment of a downstream user, as CNTs from different manufacturers each had distinctive Pb isotope signatures. Pb isotopes were not useful for identifying CNT releases within a CNT manufacturing environment, however, because the CNT signature reflected the indoor background signature. CNT manufacturing companies and downstream users of CNTs will benefit from the availability of alternative and complementary strategies for identifying the presence/absence of CNTs in the workplace and for monitoring the effectiveness of control measures.
authors.affiliation: Environmental Health Science and Research Bureau, HECSB, Health Canada, 50 Colombine Driveway, Tunney's Pasture 0803C, Ottawa, Ontario, Canada , K1A 0K9.|University of Ottawa , Earth and Environmental Sciences Department, Ottawa, Ontario, Canada K1N 6N5.
authors.forename: Pat E
authors.initials: PE
authors.lastname: Rasmussen
authors.affiliation: Environmental Health Science and Research Bureau, HECSB, Health Canada, 50 Colombine Driveway, Tunney's Pasture 0803C, Ottawa, Ontario, Canada , K1A 0K9.
authors.forename: Mary-Luyza
authors.initials: ML
authors.lastname: Avramescu
authors.affiliation: Environmental Health Science and Research Bureau, HECSB, Health Canada, 50 Colombine Driveway, Tunney's Pasture 0803C, Ottawa, Ontario, Canada , K1A 0K9.
authors.forename: Innocent
authors.initials: I
authors.lastname: Jayawardene
authors.affiliation: Environmental Health Science and Research Bureau, HECSB, Health Canada, 50 Colombine Driveway, Tunney's Pasture 0803C, Ottawa, Ontario, Canada , K1A 0K9.|University of Ottawa , Earth and Environmental Sciences Department, Ottawa, Ontario, Canada K1N 6N5.
authors.forename: H David
authors.initials: HD
authors.lastname: Gardner
mesh_terms: D000336:Aerosols / Q000032:analysis; D016902:Air Pollution, Indoor / Q000032:analysis*; D007554:Isotopes / Q000032:analysis; D007854:Lead / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods; D008670:Metals / Q000032:analysis; D036103:Nanotechnology / Q000379:methods; D037742:Nanotubes, Carbon / Q000032:analysis*; D017132:Workplace
chemical_list: D000336:Aerosols; D007554:Isotopes; D008670:Metals; D037742:Nanotubes, Carbon; D007854:Lead