New measures for airborne nanomaterials
New methods and tools for measuring exposure to airborne engineered nanomaterials will be required to protect the health of workers, according to two occupational health experts writing in the inaugural issue of the journal Nanotoxicology.
The article, 'Assessing Exposure to Airborne Nanomaterials: Current Abilities and Future Requirements,' written by Andrew Maynard, chief science advisor at the Wilson Center's Project on Emerging Nanotechnologies, and Robert Aitken, director of strategic consulting at the Institute of Occupational Medicine can be viewed online at www.nanotoxicology.net.
“Airborne engineered nanomaterials present complex exposure measurement challenges,” Maynard said. “Conventional approaches - measuring the mass of airborne material - will not always be sufficient. This presents a challenge because studies have indicated that, on a mass-for-mass basis, certain nanometer-scale particles may be more toxic than larger particles with a similar composition. In other words, smaller particles may be more harmful than conventional thinking would lead us to believe.”
Maynard and Aitken conclude that current approaches of measuring the number of particles in a volume of air, surface areas, and mass concentration, will all be useful to some degree. However, further research is needed to identify which is most important for specific nanomaterials and which measurement methods are most effective.
The authors advocate developing a new “universal aerosol monitor” capable of providing detailed information on the nature of airborne engineered nanomaterials to which people are exposed.
The proposed wearable sampling device would measure aerosol number, surface area, and concentration mass simultaneously and would be low cost. Today, stand-alone instruments can perform the individual types of measurements called for by Maynard and Aitken. “Bringing these technologies together into a single package within the size and cost parameters discussed does present a significant challenge,” they write.