The goal of this research was to assess the release of engineered nanomaterials into the laboratory when handling and preparing nanomaterials for mixing into environmentally-relevant matrices. Air-borne fullerene (C60), underivatized multi-walled carbon nanotubes (Raw MWCNT), hydroxylated MWCNT (MWCNTOH), and carbon black (CB) were measured as the nanomaterials were weighed and transferred to beakers filled with water, as well as when sonicated in de-ionized water and reconstituted freshwater with natural organic matter (100 ppm). Airborne nanomaterials were measured for 20 minutes using a handheld condensation particle counter, confirmed by transmission electron microscopy, and expressed as total particles per cubic centimeter of sampled air within six specific size ranges from 300-10,000 nm. After adjustment for background particle number concentrations, it was evident that increases in air-borne particle concentrations occurred for each nanomaterial except CB during weighing. Air-borne particle concentrations were inversely correlated with particle size. Sonicating nanomaterial-spiked water resulted in increased air-borne nanomaterials. The increase in air-borne nanomaterials after sonication was most evident with MWCNT-OH, the more hydrophilic form of MWCNT, in water with natural organic matter and CB, a natural functionalized carbon-based NM. In conclusion, engineered nanomaterials, especially when functionalized or in water containing natural organic matter, can become air-borne when mixed in solution by sonication, putting workers at increased risk of occupational exposure of air-borne nanomaterials.
Airborne-particles; Biological-effects; Biological-factors; Cellular-reactions; Cell-biology; Cytology; Environmental-exposure; Environmental-hazards; Exposure-assessment; Exposure-levels; Exposure-methods; Health-hazards; Irritants; Inhalation-studies; Lung-cells; Lung-disorders; Lung-irritants; Microscopic-analysis; Microscopy; Occupational-exposure; Occupational-hazards; Occupational-health; Particle-aerodynamics; Particulates; Pulmonary-system-disorders; Respiratory-irritants; Respiratory-system-disorders; Nanotechnology
The Toxicologist. Society of Toxicology 48th Annual Meeting and ToxExpo, March 15-19, 2009, Baltimore, Maryland