Potential for Occupational Exposure to Engineered Carbon-Based Nanomaterials in Environmental Laboratory Studies

• Published in: Environmental health perspectives Vol. 118; no. 1; pp. 49 - 54
• Main Authors: Johnson, David R., Methner, Mark M., Kennedy, Alan J., Steevens, Jeffery A.
• Format: Journal Article
• Language: English
• Published: Research Triangle Park, NC National Institute of Environmental Health Sciences 01-01-2010; US Department of Health and Human Services
• Subjects: Aerosols - adverse effects; Aerosols - analysis; Air Pollutants, Occupational - adverse effects; Air Pollutants, Occupational - analysis; Air sampling; Biological and medical sciences; Carbon nanotubes; Chemical and industrial products toxicology. Toxic occupational diseases; Chemical suspensions; Engineering; Environmental Health; Environmental laboratories; Fullerenes - adverse effects; Fullerenes - analysis; Health aspects; Humans; Hydroxylation; Inhalation; Inorganic dusts (pneumoconiosises) and organic dusts (byssinosis etc.); Laboratories; Medical sciences; Microscopy, Electron, Transmission; Nanomaterials; Nanotechnology; Nanotubes; Nanotubes, Carbon - adverse effects; Nanotubes, Carbon - analysis; Nanotubes, Carbon - ultrastructure; Occupational Exposure; Occupational health and safety; Particle Size; Quality management; Radiation counters; Solutions; Sonication - adverse effects; Soot - adverse effects; Soot - analysis; Toxicology; Ventilation systems; United States; Human; Laboratory study; Sonication; Ecotoxicology; aerosolization; nanomaterials; Occupational exposure; Laboratory staff; multiwalled carbon nanotubes; Multiwalled nanotube; Aerosols; Environment; Occupational medicine
• ISSN: 0091-6765; 1552-9924
• DOI: 10.1289/ehp.0901076

Background: The potential exists for laboratory personnel to be exposed to engineered carbonbased nanomaterials (CNMs) in studies aimed at producing conditions similar to those found in natural surface waters [e.g., presence of natural organic matter (NOM)]. Objective: The goal of this preliminary investigation was to assess the release of CNMs into the laboratory atmosphere during handling and sonication into environmentally relevant matrices. Methods: We measured fullerenes (C60), underivatized multiwalled carbon nanotubes (raw MWCNT), hydroxylated MWCNT (MWCNT-OH), and carbon black (CB) in air as the nanomaterials were weighed, transferred to beakers filled with reconstituted freshwater, and sonicated in deionized water and reconstituted freshwater with and without NOM. Airborne nanomaterials emitted during processing were quantified using two hand-held particle counters that measure total particle number concentration per volume of air within the nanometer range (10-1,000 nm) and six specific size ranges (300-10,000 nm). Particle size and morphology were determined by transmission electron microscopy of air sample filters. Discussion: After correcting for background particle number concentrations, it was evident that increases in airborne particle number concentrations occurred for each nanomaterial except CB during weighing, with airborne particle number concentrations inversely related to particle size. Sonicating nanomaterial-spiked water resulted in increased airborne nanomaterials, most notably for MWCNT-OH in water with NOM and for CB. Conclusion: Engineered nanomaterials can become airborne when mixed in solution by sonication, especially when nanomaterials are functionalized or in water containing NOM. This finding indicates that laboratory workers may be at increased risk of exposure to engineered nanomaterials.