This magazine has identified the concern previously about possible occupational hazards from nanoparticles or “NPs.” (See editorial “Nano! Nano!” in the February/March 2009 edition.) As scientists struggle to measure these potential hazards, a research institute in Quebec has released a best practices guide to help prevent their exposure in the workplace. Quebec is investing heavily in nanotechnology. Most Quebec universities have research teams working on the development of new nanoparticles, new products, or new nanotechnological applications. More than 60 nanotechnology companies have been established or are in start-up phase in the province.
NPs are classified as solid particles with at least one dimension of less than 100 nanometers that may be applied in a range of products from paints to computer processors and medical diagnostic tools. While these technical marvels may be useful, workers in research laboratories and production and transformation processes could be exposed to NPs. There’s also a downstream threat to waste industry professionals once the particles enter the waste stream, and to the public if they escape into the natural environment.
Claude Ostiguy, PhD, co-author of the new guide and a researcher at the Institut de recherche Robert-Sauv en sant et en scurit du travail (IRSST), says that information on the toxicity of NPs is still extremely limited. However, Ostiguy points out that experiments on animals have found that NPs can be distributed through different organs, retained in the lungs, and lead to effects such as pulmonary inflammation, fibrosis, pneumonia, and kidney disease. NPs can contribute to explosions and fires, posing an environmental risk as well.
So far, researchers have determined that NP toxicity is related to factors like the number of particles, size distribution, and surface area. A smaller NP is more likely to contribute to an explosion because it contains more potentially reactive activity, while an NP with a greater percent of surface molecules will interact differently with biological fluids.
But because toxicity varies from one NP to another, current scientific models can’t predict that toxicity, Ostiguy says.
Some other challenges to evaluating a worker’s exposure include discriminating between NPs and other dusts, measuring low concentrations in some work environments, and using cumbersome, expensive measuring equipment that can be unsuitable for workplaces.
Ostiguy says that even when using a quantitative risk assessment model that looks at everything from emission factors in production levels to an NP’s interaction with macromolecules, it’s still impossible to quantity exposure or effects.
“We are dealing with some major uncertainty,” Ostiguy says, adding that where there is uncertainty, workplaces should adopt a preventative, even precautionary approach.
Providing training and information, ensuring the regular cleaning of work areas, and maintaining equipment are some of the administrative measures that can help reduce worker exposure.
But training may be trickier in some workplaces like university laboratories, where there is “a mobile population of students coming in and out,” he points out.
University labs also face other challenges, like the use of protective equipment.
Different types of respirators, from facemasks to full bodysuits, may be able to prevent exposure, but Ostiguy asks, “Can you see a student wearing a full bodysuit? Imagine the panic of someone walking by the classroom!”
The manufacturing industry is not without its challenges, either. Ostiguy says that NPs can get trapped in equipment, putting maintenance workers at risk because they are “the more exposed but also the less informed.”
Some workplaces may be able to prevent or reduce exposure through good engineering techniques like the design, enclosure or ventilation of an area where NPs may be produced.
Ostiguy says that, ideally, NPs should be created in a closed circuit, recovered and used in a humid environment, then integrated into the final product — all without human handling. He admits, however, that this is nice in theory, but difficult in production.
“In Canada, I don’t know of a single company planning to do this,” he says.
Globally, the most common preventative practice is the use of laboratory fume hoods, followed by glove boxes, vacuum systems, and white rooms, according to consultations with companies and researchers in nanotechnology.
Yet, in terms of legislation directly regulating NPs, Ostiguy says that there is almost none in the world, adding that the lack of scientific data makes setting exposure limits impossible.
Nor are producers required to inform people that a product could contain NPs.
“The supplier cannot go farther than science has,” Ostiguy says. He also says there is ongoing research into public safety concerns surrounding over 800 different products like sunscreens and golf clubs that could contain NPs. As well, researchers are looking into the environmental impacts from the entire lifecycle of nanoparticle-containing products.
Despite all the uncertainties and challenges surrounding NPs in the workplace, Ostiguy says that “the good news is that our current knowledge allows exposure to be controlled.”
The new guide “Best Practices Guide to Synthetic Nanoparticle Risk Management” is available at the IRSST website, www.irsst.qc.ca
Erika Beauchesne is a writer with Eco Log in Toronto, Ontario. This article is adapted from a story that first appeared on our affiliate environmental news service at www.ecolog.comContact Erika at firstname.lastname@example.org
“‘In Canada, I don’t know of a single company planning to do this,’ Ostiguy says.”