Nanomaterials — man-made particles made of carbon, silicon and metals and much smaller than the width of a human hair—are already used in consumer products including stain resistant clothing, cosmetics, food additives and drug delivery systems. But nanomaterials share certain similarities with toxic asbestos fibers and too little is known about the health risks posed by nano materials.

An expert panel of the National Academy of Sciences recommended this week that a better understanding is needed of the risks of adverse health and environmental effects posed by nanomaterials in light of their rapidly expanding production and use in society. Materials that behave in unconventional ways because of their size may produce unanticipated health effects, the panel said. The concern was supported by research in the 1990s that showed that inhaled fine particles have the potential to cause more serious health effects than shown in studies of larger particles.

Nanomaterials share certain characteristics with asbestos fibers, raising concerns that they may increase risks of respiratory diseases such as lung cancer and mesothelioma, a cancer of the lining of the lung and abdomen. Approximately 3,000 people a year in the U.S. die of mesothelioma due to past exposure to asbestos. A heat resistant mineral fiber, asbestos was used in thousands of products for decades before its use was restricted due to its cancer-causing properties. The symptoms of asbestos-related disease typically appear decades after exposure.

Both asbestos and nanomaterials have fiber-like characteristics in their thin, elongated shape. They are so small that people may unknowingly inhale them, causing the fibers to penetrate deep into the lung and lodge there, causing inflammation.  Nanomaterials are being used in consumer products so people could  inhale or ingest them.

A 2009 article by French researchers in the journal Particle and Fibre Toxicology noted that studies of carbon nanotubes have shown  adverse effects similar to those observed with asbestos fibers and two recent studies by Japanese researchers showed the occurrence of malignant mesothelioma in mice and rats exposed to carbon nanotubes.

The diverse properties of nanomaterials make them challenging for researchers to assess the risks, the expert panel said. The toxic effects of nanomaterials will likely vary depending on the base materials of which they’re made.

For more information about mesothelioma and asbestos disease, click here.