Sacramento Bee
Letters to the Editor

Dear Editors,

Would you please consider publishing the following letter on soil contamination by tremolite asbestos in El Dorado County?  It is a follow-up on the last article by Mr. Chris Bowman on contamination of soils at oak Ridge High School. We believe the issue and our letter is of great public health importance. However, we add a specific condition to this potentially controversial and legally liable letter.

The four authors have carefully worded and agreed on the following letter after many iterations. May we ask that you publish this letter in its entirety, or else not modify it without our approval. Indeed, we may disavow any version revised without our approval. We do not want to be difficult, but our past experience (totaling 80 years in the asbestos arena) warns us against distortions that often result from well-intended but profane editorial changes. Of course, formatting and spelling corrections is your privilege.

Would you kindly let us know if and when this letter would be published?

Thank you for considering this letter and for your understanding.

Michel Camus
Michel Camus, Ph.D., epidemiologist
   10881 Durham St.
   Montreal (Qc)
   H2C 2G8

Should children be exposed to soils containing more asbestos than we tolerate for workers?

We congratulate the Bee for its article on tremolite asbestos contamination of soils in the Oak Ridge High School grounds.


As scientists concerned with asbestos and its health effects, we believe that thorough exposure and risk assessments should be undertaken to assess the extent of the problem, but that sufficient evidence exists to take preventive measures without delay. Local civil authorities gravely misunderstand the potential health risks. We submit the following facts and proposals to their attention.

1. "Asbestos" refers to different mineral fibers classified by regulatory agencies as demonstrated human carcinogens.

2. Tremolite asbestos is even more carcinogenic than usual commercial asbestos (chrysotile).

3. Respirable tremolite fibers are easily inhaled and stay in the lungs for virtually lifetimes.

4. Tremolite-contaminated soils have already caused clusters of cases of mesothelioma (a rare and fatal cancer strongly related to asbestos exposure) in other areas of the world including New Caledonia, Turkey, Greece, Montana.  

5. Soil samples containing 1%-5% tremolite asbestos by weight have been found on Oak Ridge High School's grounds.


6. Authorities are falsely reassured because air monitoring did not show high levels of airborne tremolite during excavation work at Oak Ridge High School. In fact, workers were watering the dust and soil. Measurements taken in such conditions say nothing about potential exposures of children and adults walking, running, playing or riding on dry tremolite-contaminated soil.

7. As shown in Libby, Montana, disturbing dry tremolite-contaminated soil can generate airborne asbestos levels above current U.S. occupational standard for an eight-hour working day. This has also been suggested in other studies.

8. Exposures due to activities disturbing asbestos-contaminated soil cannot be assessed by standard passive air monitoring methods because exposures are local and episodic with durations depending on the activity. Simulations of such activities should be conducted with proper sampling in the breathing zone to assess potential peak exposures. A survey should be conducted to determine the types of persons most likely exposed to such activities. Finally, appropriate preventive and educational measures should be implemented. 

9. The U.S. E.P.A. defines hazardous "asbestos-containing materials" as having 1% asbestos content by weight. U.S. health protection authorities have set stringent controls and regulations to protect workers handling such materials. The California Air Resources Board has prohibited the use of gravel containing more than 0.25% asbestos to cover driveways, parking lots and roads under cancer-protection rule ATCM 93106. Why not protect similarly children exposed to soils containing 1-5% asbestos?

10. Similar or higher soil contamination occurs throughout El Dorado County and beyond.


11. Since El Dorado county has undergone rapid development over the last 10-20 years, and since mesothelioma usually does not develop until 30-50 years after first asbestos exposure, we will not likely see the health effects of El Dorado's tremolite exposures before year 2020. Likewise, 'normal' chest x-rays today are no indication that hazardous exposures have not occurred nor that asbestos-induced cancer processes have not already begun. The cancer risk could materialize around year 2020 if authorities do not act now to prevent unnecessary tremolite exposures. 

In conclusion, one should beware not to hide his/her head in the ... soil! The risk should be assessed over the larger El Dorado County area because soil contamination with asbestos extends beyond the high school grounds. The "precautionary principle" should apply most of all with children. These issues should be addressed and the recommended studies and measures be undertaken as soon as possible. In the interim, authorities should consider suspending construction activities in or near proven or suspected deposits of tremolite asbestos, in California as anywhere else in the world.

Michel Camus, Ph.D., epidemiologist, Healthy Environments and Consumer Safety, Santé Canada, Montreal

Arthur Langer, Ph.D., mineralogist, Deputy Executive Office, Ph.D. Program in Earth and Environmental Sciences, City University of New York

Bruce W. Case, MD, MSc, DOH, Assoc. prof., Dept. Pathology & School of Environment, McGill University, Montreal

Jerrold Abraham, MD, professor of pathology, director of Environmental and Occupational Pathology, State University of New York, Upstate Medical University, Syracuse (licensed MD in California)


Disclaimer: This letter reflects our personal opinions based on our experience as scientists in this field, and do not imply any approval or consent by any of the institutions with which we are affiliated: affiliations are stated for identification purposes only.