NIOSH Research Methods Demonstrate that Breathing Nanoparticles May Result in Damaging Health Effects

Granulomatous inflammation in the alveolar region 28 days after inhaling single-walled carbon nanotubes.

A Story of Impact:

Nanotechnology has the potential to revolutionize countless products, create computers smaller and faster than once could be imagined, and fight diseases such as cancer. According to the Project on Emerging Nanotechnology, by the summer of 2009 there were 1,015 consumer products using nanotechnology. That represents nearly a 19-fold increase over the 54 products listed in 2005. Nanotechnology involves the manipulation of matter at a near-atomic scale. Nanoparticles measure from 1 to 100 nanometers in size, with 1 billion nanometers forming a meter. For comparison, a billion inches would nearly circle the Earth 2 times.

A nanoparticle of a certain material can behave much differently than a larger, more familiar-sized particle of the same material. Early research shows that materials that enter the body as nano-sized particles may have harmful health effects, even for some materials previously considered safe at larger sizes.

The National Institute for Occupational Safety and Health (NIOSH) is a leader in researching the health effects that nanoparticles may have on workers who handle them and who are exposed to them. NIOSH recently published research that measured for the first time the health effects of inhaling a common nanoparticle, the single-walled carbon nanotube. In this study, researchers examined what happens when mice breathe in carbon nanotubes.

Previously, scientists studied mice by using aspiration, or mixing the nanotubes in a fluid that is then delivered into the respiratory system of the mice. The aspiration experiments found that the immune system reacted to nanotubes in the same way as an infection. Strong inflammation produced swelling, scarring, and genetic mutations to cells in the lungs of the mice. There were two major critiques of the aspiration research. First, nanotubes were introduced into the lung as a single bulk amount, and second, the particles tended to clump together when mixed in the fluid. Researchers wondered what effects would be produced by inhalation of the particles because nanotechnology workers can be exposed to situations where they could breathe in particles in the air.