es as “new” chemicals—which puts the onus on the industry to prove they’re safe.
Because of their extremely small size, measured in billionths of a meter, nanoparticles act differently from their larger versions. They have far more surface area, which makes them more reactive with their surroundings; and they’re small enough to pass through cell walls and interfere with biological processes.
Some nanomaterials are already known to be dangerous, and they need to be better assessed, the California study says. Carbon nanotubes, used in electronics and to strengthen sports equipment, may pose risks similar to asbestos fibers, which can cause fatal lung damage if inhaled. Other studies have shown genetic and developmental damage in mice resulting from exposure to nano-scale titanium dioxide—a common ingredient in suncreens and UV-blocking clothing.
The California Department of Toxic Substances Control in January asked industries making or importing carbon nanotubes to report how they handle the materials, and how they’re tested for safety. A spokeswoman said the new study would not change the department’s current strategy of seeking more information on how certain nanomaterials are used and tested.
The city of Berkeley is apparently the first in the country to require researchers and manufacturers to disclose what nano-based materials they’re using or making, how they’re handling them, and to what extent they’re toxic. In the latter case, the problem is that in many cases, they don’t know.
(This story originally appeared on the New Haven Independent web site on June 23, 2010.)