On the impacts of nanotechnology

Barry Castleman, an environmental consultant and expert on workplace health hazards, tells Arnab Pratim Dutta about nanotechnology's impacts

By Arnab Pratim Dutta
Published: Thursday 31 January 2008

Down to EarthWe hear about nanotechnology everywhere but we seldom hear of its impacts. Is it good or bad?
We are just beginning to understand the nature and the extent of adverse effects that nanomaterials can cause. Nanomaterials, as the name suggests, are so small that they can easily pass through the cell wall. They are also capable of crossing the blood-brain barrier--a membrane in brain capillaries that normally doesn't allow any toxic particle in the bloodstream to enter into the brain.

Hence they represent a particular level of threat. But we are yet to know whether the technology is good or bad. I expect both. This will depend on its applications: whether its use as solar collectors and in medical applications will come up first or its indiscriminate commercial use in the cosmetics sector and household appliances will unleash some kind of tragedy.

What nanotech products do we use in our daily lives? What are the possible dangers?
Currently there is a growing use of nanotechnology in the cosmetics sector. Earlier, sunscreen lotions used to look white when smeared on the face. But with nano-sized particles, the lotion looks clear after applying to skin. Cosmetics with such advantages are in huge demand in the market. About 400 cosmetics products across the world are based on nanotechnology and the us alone holds approximately 6,800 nanotechnology-related patents.

But, there are fears that such creams may penetrate our skin and enter the bloodstream. Despite this, there is no pre-market testing on the kinds of long-term damage that nanomaterials can cause, and the products are being introduced in the market indiscriminately.

The textile industry is also beginning to turn to nanotechnology for making fabrics that don't wrinkle. But these nanomaterials incorporated into the fabrics may get washed out and contaminate the environment. A leading company has come up with a washing machine that uses nano-silver. The company says it will help reduce smell while washing clothes. But nanomaterials will get flushed out with the wash water and pollute the environment. We are struggling to control the current level of water pollution. Imagine what will happen when the water also gets contaminated with nanomaterials.

Is there any study showing that nanomaterials can be hazardous?
Toxicological studies on nanomaterials such as carbon nanotubules have shown that when tested with animal experimentation, they can cause pulmonary fibrosis, even more rapidly and severely than asbestos does. Studies have also proved the harmful effect of nanomaterials on aquatic organisms.

Do nanomaterials affect people at the source?
People engaged in the manufacturing of nanotech products or working in labs where nanomaterials are handled may have particularly high exposure, since these are the places where nanomaterials are constantly being used. Without necessary precautions, there might be tragic effects on workers.

Could this indiscriminate use of nanomaterials lead to increased cases of cancer in coming years?
We have no assurance. Carcinogenic effects of nanomaterials, if they occur, might take 20-30 years to manifest in humans. Even if tested on animals, it takes two-three years to get the results. Hence, anti-nanotech groups are calling for government regulatory control over the industry.

Is there any regulation governing nanotechnology?
At this point there is no regulation to govern nanotechnology. Europe has just begun talking about it. Some environmental groups such as the us- based Natural Resources Defense Council are lobbying for products to carry labels informing consumers that they contain nanoparticles, while others are demanding more research on the health effects before they are introduced in the market.

Are developing countries at greater risk than the developed ones?
I think they are. Developed countries like the us have strict liability provisions. This means, a product seller is liable to any person who falls sick after using the product. If the product does not put any disclosure or warning on the label of the potential harm, then under the law it is regarded as unreasonably dangerous and the product seller is responsible for the medical costs, lost earnings and additional pain and suffering, leading to punitive damages.

This is unlike developing countries where such liabilities are relatively low or non-existent. National differences in public awareness, regulation and liability are now leading to a preferential drift for the hazardous industry to the third world.

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