It doesn't sound right to me. I took a basic geology course in college and the prof said that only some forms cause cancer, and most don't. 'Course he could have been wrong, but I remember reading the same thing somewhere else.
Perhaps all could cause cancer with sufficient exposure for their type. For example, type A could cause cancer with minimal exposure, whereas type B could cause cancer with 100 years of breathing it's condensed form from a paper bag. Maybe that's where the confusion comes from?
Now, even one of those two authors has written another series called "Living Off The Fat Of The Land," describing the sinister nature the EnvironMental Movement has morphed into as nothing but a massive fundraising movement using the Jesse Jackson SHAKEDOWN technique. Huge salaries and expense accounts in extravagant office buildings and rich tax favored pensions, etc.
To me, this is equivalent to "yelling FIRE in a crowded room" and should not be protected freedom of speech!!!
This irresponsible, so-called journalist, is tormenting and terrifying the parents of these students in exactly the same way that terrorists terrify people with their agenda's and it's all based on supposition, not science and is purely to frighten the Sierran Counties into stopping any further disturbance of the soil by building anything new to accomodate productive human growth and freedom!!!
That also makes it UN-American!!!