Clapper, Patti, Schweizer and Mason

Exposure to asbestos is scientifically proven to cause a variety of illnesses, including mesothelioma (cancer in the lining of the lungs, abdomen, or heart), asbestosis (scarring of the lung tissue), and lung cancer.  Mesothelioma is the most aggressive and lethal, with no known cure. 

For many years now cancer, including mesothelioma, has been the leading cause of death in Japan.  One of the main types of asbestos used in Japan is chrysotile, also known as white asbestos.   Although the United States pretty much banned the use of all types of asbestos in the mid-1980’s, Japan continued to use chrysotile in many building and industrial products. 

Because of the continued use of asbestos, future mortality rates due to mesothelioma is increasing in Japan and is not expected to peak for another 25 years.    Symptoms of mesothelioma are non-specific and do not begin to appear until decades after exposure, making it very difficult to diagnose in early stages.  Most patients diagnosed have very poor prognosis.

Currently, the Ministry of the Environment in Japan is looking into ways to not only treat asbestos-containing waste but also to replace asbestos with a similar fire and heat resistant mineral that does not cause cancer or other related diseases.  One avenue they are looking into is to replace the use of chrysotile (CH) with forsterite (FO-1000).  Forsterite is created when CH is heated to over 800 degrees Celsius and, when converted, is anticipated to have the same properties as asbestos, thereby being a viable substitute. 

In light of the proposed use of FO-1000, the continued use of chrysotile, and increasing numbers of diagnosed pleural mesothelioma cases, researchers at the St. Marianna University School of Medicine in Kawasaki, Japan decided to do a study in hopes of learning more about the use of biomarkers to detect mesothelioma at earlier stages, especially in high risk populations. 

The researchers were specifically investigating the use of serum N-ERC/mesothelin levels as a biomarker to evaluate:

1. exposure effects of CH and FO-1000, and
2. development of mesothelioma and disease of respiratory organs due to exposure

Using a rat model, three groups were formed:  a control group, one exposed to only CH, and the last exposed only to FO-1000.  No changes were observed in the control group, while significant yet different changes were seen in the infected groups. 

Overall observations led the researchers to suggest that serum N-ERC/mesothelin could be a useful early-phase biomarker to evaluate carcinogenic risk to respiratory organs after exposure to either CH or FO-1000.  They further recommend that protective measures be taken for any workers who will be handling FO-1000, as the tests showed development of disease after exposure, although at lower levels than those who were exposed to CH. 

The study recommends further research into using serum N-ERC/mesothelin concentrations and 8-OHdG levels as an effective screening tool for early phase organ toxicity and disease development.