Check out this article on Nanoparticles by Brenda Wiederkehr. It was featured in the summer edition of The Leader!
"Nanoparticles: When did humans first begin to experience and be exposed to nanoparticles? Well . . . forever. The term nanoparticles refer to molecules that are measured on the nanoscale, typically 100 nanometers or less in size. How big are we talking about? Nanoparticles are extremely tiny. If you were to expand a nanoparticle up to the size of a football, then correspondingly a red blood cell would become as big as a football field, and a donut would be as big as the islands of New Zealand. They are pretty small, 10-9 meters. In fact, if we talk about asbestos fibers measured in the micrometer range, they are particles 1,000 times larger than nanoparticles. No wonder there is little benefit from using the workplace barriers designed for these much larger particles when working with nanoparticles.
There are many categories of nanoparticles identified and new structures created on a continuous basis. Some of the basic classes of nanoparticles include:
Carbon-based particles:
Fullerenes which are cage-like structures
Carbon nanotubes which may be single
walled or more complex
Buckyballs which are 60 atom ball
shaped spheres
Metal-based:
Quantum dots (i.e. silicone with germanium or cadmium with selenium)
Metal oxides (i.e. Titanium Dioxide)
Pure metal nanoparticles (i.e. silver, gold) Nanoparticle polymers (i.e. silicone
nanospheres much harder than silicon with a hardness between sapphire and diamond)
Nanoparticle Conglomerates (i.e. DNA biocomposites where DNA and nanoparticles are combined)
As mentioned, we encounter nanoparticles all the time. We have been exposed in nature well before we began creating them in industry and laboratories. Viruses are often nanoparticle sized, but so are particles found in ocean spray, volcanic ash, fine sand and dust. Humans create nanoparticles when we make fire, run a diesel engine, in large-scale mining or in many activities we commonly perform. These are called incidental nanoparticles. We are already surrounded by manufactured or engineered nanoparticles. They may be found in products ranging from tires to sunscreen. They are in our food. For example, a Korean company boasts that each milliliter of colloidal silver they produce to coat food containers, which provides a 99.9 percent antibacterial effect, contains 25,000 silver particles and each container holds a 500,000 billionth of a meter-sized silver particle. We eat from those containers.
Basically we are taking substances we are familiar with and know the toxicity of, and converting them, by virtue of size, to materials that behave differently and for which we have little idea of the health effects. As creatures, we are composed of majority water, and substances this size may flow in ways through our bodies we have yet to understand. The early data raises questions. Yet the benefits drive the push to create new and different substances every day.
In the last decade, there has been a virtual explosion of product development for nanoparticles. Over 1,800 consumer products now list nanoparticle ingredients. (www.nanotechproject.org/cpi/browse/)
These products are being created in laboratories all over the world without any toxicity studies. We do not know toxic levels. We do not know lethal levels. At the same time, there has been a wave of medical research trying to identify how these entirely new materials react with our bodies and the environment. Scientists bemoan the fact that the researchers are often inexperienced at doing formal toxicology studies and the data is very hard to use or interpret. Articles that raise alarm with regard to the health effects are often followed by articles showing that
the studies were based upon exposures or routes of exposure that do not simulate realistic or reasonable exposures at work or at home. There is no handbook to give defnitive guidance.
Any occupation in which exposure to nanoparticles is routine or anticipated should provide all levels of control, including administrative, engineering and personal protective equipment. Current and ongoing research of the medical and safety literature for any substance which may be used
should be done at the onset of use in a work environment AND should be reviewed at regular intervals. The help of a toxicologist and a safety engineer may be useful to assure the best level of safety be afforded to our workers. While there has been less public concern about nanotechnological hazards than GMO products, the truth is, we just don’t have any idea of the long-term health hazards created by the new materials being developed and placed in our environment each day. From a workplace safety standpoint, it is prudent to deal with nano- sized materials in the same way as any hazard for which we do not know the toxicity or health risks. We have to assume our standard personal protective equipment, particularly the respiratory protective devices, may not offer the level of protection we may desire, and perhaps we should shift focus to other mechanisms of control. A careful hazard risk analysis, to the best of our current abilities, should be done."
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