Carbon Nanotubes: Shape May Impact Mesothelioma Risk

Like asbestos fibers, multi-walled carbon nanotubes (MWCNTs) are small enough to be inhaled or accidentally ingested as dust. Unlike asbestos, which occurs naturally and is mined for commercial use, MWCNTs are synthetic. These carbon-based molecules are shaped into concentric tubes which resist chemical corrosion and are valuable for use in electronics, optics, textiles, and other areas of manufacturing.

A new study contains more disturbing news for people who work in certain areas of materials science. Researchers have once again connected inhalation of multi-walled carbon nanotubes with the risk of developing malignant mesothelioma, a deadly cancer most often associated with asbestos.

All of the treated rats developed malignant peritoneal mesothelioma, which was confirmed by microscopic and immuno-histo-chemical evaluation. Most of these MWCNT - induced mesothelioma tumors occurred not only on the peritoneum lining the abdomen, but also spread into peritoneal organs, suggesting an aggressive malignancy.

The goal of the new German study was to identify possible carcinogenic effects of MWCNTs and to determine how the cancer triggered by these molecules compares to mesothelioma triggered by asbestos. The team injected different shapes and sizes of MWCNTs into the abdomens of 500 lab rats. A control group of rats received injections of amosite asbestos.

But, even though mesothelioma developed in all cases, there were differences in the time it took for tumors to occur. The researchers theorize that the differences may lie in the shapes and sizes of the MWCNTs.

The researchers report that, regardless of the cause, all of the mesotheliomas that developed in the rats were similar to each other and to human mesothelioma. The team concludes that all types of MWCNTs have the potential to cause mesothelioma, but that certain varieties are more carcinogenic than others. Mesothelioma is a highly aggressive cancer that is currently considered incurable. The new study appears in the journal Particle and Fibre Toxicology.

What is mesothelioma?

Mesothelioma is a form of lung cancer that is almost always caused by exposure to asbestos, and usually located in the outer lining of the lungs called the mesothelium. Most people who develop mesothelioma contract this cancer through breathing in asbestos fibers or being exposed to asbestos dust while on the job. In cases where mesothelioma was found in a person without occupational exposure, it is summized that exposure may have stemmed from asbestos fibers found on the clothing someone in your house who has worked in the area where asbestos dust was found.

There are many reasons that make diagnosing mesothelioma in its early stages is very difficult. Symptoms of mesothelioma may have a latency period of anywhere between 20 to 50 years after the initial contact of asbestos, which means that the time symptoms begin to appear, the cancer is already in its advanced stages. Once symptoms are present, the diagnosis is still not a fast process. There are a number of diseases that mirror the symptoms of which are located in mesothelioma patients and because mesothelioma is often the last stop - usually without mention of the patient about the possibility of previous exposure to asbestos.The success of treatment for mesothelioma depends on the phase in which the cancer is found. As it was found that the majority of mesothelioma is not detected until the advanced stages, mesothelioma treatment is often referred to as "unsuccessful." Studies show that when they are inside or stage I or II, treatment for mesothelioma - usually with a combination of radiation and chemotherapy - successfully expanding patient's life for five years at a rate of 74.6% (Wikipedia). There are alternative forms of therapy that can be used in combination with conventional treatments, which are shown on occasion to reduce the size found in mesothelioma patients.

Asbestos has been used for many years in a wide range of household and industrial products because of their multiple types and purposes. It is nonflammable, and can also be used as an insulator, so it will become very popular during the Industrial Revolution. It is not known whether or not people are aware of the dangers of asbestos fibers at the time, but by 1900's risk of asbestos is more obvious. People who have lived in mining towns will develop lung problems, and general studies have shown that asbestos workers died at an early age.Asbestos in the undisturbed state, seems not to pose a threat. However, as soon as it becomes damaged or friable, fibers could be ingested, thus potentially leading to these or other health problems. Although some companies were aware of this danger, they continued to work with products containing asbestos, regardless of their employees. These blatant injustices are the reason for the popularity of mesothelioma in the area of ​​litigation.