Filter Efficiency Studies Highlight Second Symposium on Nanotechnology

When talking about the Second International Symposium on Nanotechnology and Occupational Health and the progress stakeholders are making in developing real-world mechanisms for minimizing the potential hazards of nanoparticles in the workplace one industrial hygienist remarked that there still seem to be more "what ifs?" than "how abouts?"

While such a remark is a "very valid criticism" that's been echoed by other stakeholders, the safety and health community is making progress toward coming up with real answers to the questions troubling those who face the challenge of protecting workers from the potential hazards of nanoparticles, said Andrew Maynard, co-chair of the symposium and chief science advisor for the Woodrow Wilson International Center for Scholars and Pew Charitable Trusts Project on Emerging Technologies.

"We're still in the phase where an awful lot of education is going on," Maynard explained. "The next phase has to be moving from the initial information phase to developing hard information and making decisions based on that hard information."

That many stakeholders are still coming up to speed on the fundamental concepts of nanotechnology was clear from the symposium's structure: The first day was dedicated entirely to tutorials, which included "Basic Nanotechnology," "Fundamentals of Aerosol-Based Engineered Nanoparticles" and "Basic Principles of Occupational Health and Safety Application to Ultrafine Aerosols."

Maynard and co-chair David Pui of the University of Minnesota point out in the symposium's program that addressing the potential risks of nanotechnology "demands far-reaching interdisciplinary collaboration," and Maynard told Occupational that the tutorials were designed to "educate people in these very disparate disciplines and that seemed to work very effectively."

Filters Might Offer Protection

While most stakeholders would agree that there seem to be more questions than answers regarding the potential hazards of nanoparticles, Maynard noted that researchers are beginning to make some breakthroughs.

He pointed to several studies, and their corresponding presentations at the symposium, which analyzed the effectiveness of respirators and filters against nanoparticles. One in particular "Filter Collection Efficiency for Engineered Nanoparticles," a NIOSH-funded study conducted by the University of Minnesota "was the first time we've seen good, scientific data showing that filters are effective in removing very small particles from the air," Maynard said.

The study exposed four different filters to silver nanoparticles ranging from 3 to 20 nanometers in size and found that filtration effectiveness increased as particle size decreased for all of the test filter media.

Maynard noted that the fact that such progress has been made in understanding the effectiveness of filters against nanoparticles is an example of how stakeholders have made progress since the first symposium, which was held in October 2004 in the United Kingdom. The second symposium was held Oct. 3-6 in Minneapolis.

"We're moving from basing our assumptions on theories to being able to base recommendations on experimental data," Maynard said.

The next symposium which is slated for 2007 in Taiwan is hoped to be one that looks at a "more mature area of research," Maynard said.

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