Naturally Occurring Asbestos (NOA) in El Dorado, California: Tremolite Asbestos in Dog's Lung
The health hazards of asbestos are well recognized and documented.
Naturally occurring deposits of asbestos cause no human exposure if left undisturbed below the earth's surface, of course. However, development of areas rich in asbestos fibers can cause asbestos fibers to be released into the air, resulting in potential exposures to those humans and animals breathing that air.
Such 'environmental' exposures and their major health consequences are well documented in the scientific literature [see, for example, the presentation by Dr. Marcel Goldberg]
Using animals resident in areas of NOA as 'bio-sensors' for such asbestos exposure has been reported [See Dumortier et al.]
A dog residing in an area of NOA (El Dorado, California [see map] ) for over 13 years recently expired and his lungs were examined using light microscopy and electron microscopy. The results confirmed extremely high concentrations of asbestos fibers in his lungs [see preliminary figure]. [Mr. Terry Trent's encouragement and assistance with this investigation has been greatly appreciated, and Bryan Burnett has done much additional SEM/EDS analysis.]
It is highly likely that substantial human exposures from such developments in this area and similar areas have already occurred, and the disease burden with long latency of several decades is only beginning.
It would seem essential for Public Health to take whatever steps possible to STOP further exposures as much as possible so as to minimize the health impacts. For example, any existing and further development of roads, schools, housing etc. on such sites with exposed NOA tremolite and other types of asbestos should be carefully evaluated.
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[Bio-solubility of Lead in Mine Waste Contaminated Soils]
[An Epidemic of Accelerated Silicosis in Oilfield Sandblasters]
[Toxicologic and Epidemiologic Clues from the Characterization
1952 London Smog Fine Particulate Matter in Archival Autopsy Lung Tissues]
[Leaves: Monitors of Particulate Air Pollution?]
[Ultrafine Particles in Air Pollution]
[Interesting Examples of SEM Analyses]