Wednesday, November 26, 2014

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.

Monday, January 2, 2012

When was asbestos banned in US?

Even today, long after the fact, many people want to know the answer to the following question. When was asbestos banned?

On July 12, 1989, a final ruling was issued, by the Environmental Protection Agency, which banned the use of asbestos in the United States. This rule, known as the "Asbestos Ban and Phaseout Rule, "was overturned (in 1991) by the New Orleans 5th Circuit Court of Appeals.

 Consequently (and at of the time of this writing) some products that contain asbestos are still banned. Others are not. Banned items include product categories such as flooring felt, rollboard and new uses of asbestos.

 Items not banned include but are not limited to millboard, disc brake pads, pipeline wrap, asbestos clothing, roof coating and brake blocks.
Since the Environmental Protection Agency doesn’t track manufacturing and distribution of products that contain asbestos, in the global marketplace, it is still legal to manufacture some of the items in the U.S. They must, however, meet the requirement of being clearly labeled.

 Furthermore, due to the North America Free Trade Act, there is a possibility that U.S. banned products may still be available in the U.S. This happens when items made in Canada or Mexico are imported here.

 Some people may be surprised to learn that asbestos occurs naturally. It is comprised of six minerals that all contain oxygen and silicon.

Breathing in the thin fiber-like crystals can result in adverse and often fatal illnesses that include asbestosis, lung cancer and mesothelioma. The longer an individual is exposed to asbestos, the higher the chance of disease.

 In reality, asbestos has been used for thousands of years. It is assumed that early inhabitants of the area that is now Finland used it to strengthen cooking pots and utensils.

 Late nineteenth century builders and manufacturers began using asbestos in their respective lines of work, due to its strength and fire resistant qualities. At that time, it was commonly mixed with cement of some type and utilized as building or electrical insulation.

 It didn't fall under scrutiny, as a potentially lethal material, until the early 1900s when there was a noticeable increase in the number of cases of lung disease and death in many asbestos mining towns. The first asbestos-related death was documented in 1906.

 In conclusion, the technical answer to the question "When was asbestos banned?" only pertains to specific products. "As new and safer materials are developed, health conscious individuals can only hope that asbestos will be banned altogether.", told us from MYOVI.