Mesothelioma Threat From Nanotubes

Carbon nanotubes, a new material used in drugs, electronics, and energy-efficient batteries, may increase the risk for workers who use them of developing mesothelioma. Carbon nanotubes are either short and curly, or long and thin. Long, thin carbon nanotubes are similar to microscopic asbestos fibers in shape and size. A recently published study found that carbon nanotubes behave like asbestos fibers inside the body, and have the same potential for causing mesothelioma.

Mesothelioma is a slow-growing cancer of the mesothelium, the tissue lining the lungs and also the abdominal organs and the abdomen itself. By the time mesothelioma is diagnosed, it is so far advanced that it is invariably fatal. Life expectancy after diagnosis can be a matter of months, sometimes a few years. There are treatments for symptoms of mesothelioma, but there is no known cure.

A half century of medical research has established that the principal cause of mesothelioma is inhalation of microscopic asbestos fibers. The fibers are so dangerous because they are thin enough to be inhaled easily, and once inhaled, they lodge in the lung tissues. The body has mechanisms for clearing foreign particles from the lungs, but because of their length, asbestos fibers are not easy cleared, and can stay for decades, causing changes at the cellular level that lead to mesothelioma.

Carbon nanotubes are very light in weight, yet extremely strong. Because of these properties they are increasingly used in many high-tech applications. Yet for more than a decade, concern has been growing among nanotechnology researchers about the health effects of working with nanotubes, especially the consequences of inhaling them.

In the study recently published in Nature Nanotechnology , researchers at the University of Edinburgh studied the effects of long and short asbestos fibers, long and short nanotubes and carbon black on mice. The materials were injected into the mice's abdominal cavity, where mesothelioma also develops; Findings from the abdominal procedure can anticipate the effect in the lungs. The mice's response to long carbon nanotubes was the same as their response to long asbestos fibers; With both materials, the mice shown pathological changes in their tissue that are predictive of mesothelioma.

The study's authors called for more research into the environmental and health and safety risks posed nanotubes. It's not clear how much risk of inhalation is posed by current manufacturing processes, and if these nanotubes, once inhaled, will embed themselves in lung tissue. Manufacturers need to know whether their processes allow nanotubes to become airborne, and if so, what safety equipment is required to protect workers from inhalation. Disposal of materials containing long fiber carbon nanotubes raises similar safety questions.

The principal funders of safety research in the US are government agencies such as the Environmental Protection Agency, EPA, and the Occupational Safety and Health Administration, OSHA. Neither is currently funding studies of carbon nanotube safety.

The study looked only at the diameter and length of carbon nanotube fibers. Many other questions remain about nanotubes in which other elements have combined with the carbon, and the effects on human health of these compounds.

Nanotube technology and manufacturing is still in its infancy, and the pressure to use these versatile materials will be generous. This is the time to determine what the health and environmental implications of these materials are, and to put in place the necessary safeguards. If this is not done, another generation of American workers will face the prospect of a fatal and preventable cancer.



Source by Frederick Schenk

Comments are closed.