Once again, Los Angeles is attacking San Francisco. California State Senator Gloria Romero (East LA) has sponsored a bill (SB 624) that would remove serpentine as California’s state rock. She said:
“This bill is about raising awareness to protect the health of our citizens. Serpentine contains asbestos, a known carcinogen. Toxic materials have no place serving as emblems for the State.”
(Warning: long, nerdy, hopefully accurate science talk ahead.)
Serpentine, common in California and rare elsewhere, was designated as our state rock in 1965. Why? According to the original bill, “It is a host rock for the state’s newest and most rapidly growing mineral industry – asbestos, now bringing in several millions of dollars annually.” (Yet another tidbit I learned this evening — California was the first to designate a state rock.)
Now I know you are thinking, “Hey, I just checked out the GeographCA iPhone app and a huge swath of serpentine (dark green) bisects San Francisco.”
But some clarification is in order — not all serpentine is asbestos. No need to evacuate Potrero and Hunter’s Point. In fact, little serpentine is in asbestos form.
Warning: IANAG (I am not a geologist) but (fortunately?) for you the internet allows me to bring geological prowess directly to you.
- I always thought asbestos was one particular mineral but it’s the long and fibrous crystal form of several different minerals.
- Amphiboles and chrysotile serpentine are the two most common types of asbestos — they were considered the miracle minerals of their day given their strength and heat resistance.
- Asbestos is dangerous in powered form when airborne. Some consider chrysotile asbestos “safer” than amphiboles. Others disagree.
- There are 20 “blends” of serpentine. The most common types of serpentine — antigorite (hard, dark green) and lizardite (scaly and whiteish) — are safe.
- Chrysotile is sometime found as veins within serpentine deposits.
Electron scans show the difference.
So not all serpentine is asbestos. Lounge of the Lab Lemming summarizes the imprecision of the bill:
- There are 20 forms of serpentine, only one of which is an asbestos mineral.
- The very dangerous amphibole asbestos minerals specifically mentioned in the bill are completely unrelated to serpentine.
- Safety disclaimer: The inhalation of ANY rock dust is harmful to the lungs. Asbestos dust is particularly dangerous. Do not breathe rock dust.
I’ve been trying to find a map of the various flavors of serpentine in SF but with little luck. The SF USGS Google Earth layer doesn’t break it down, and neither Wakabayashi’s “Contrasting Settings of Serpentinite Bodies, San Francisco Bay Area” nor the Geology of the Golden Gate Headlands specify the regional makeup. A 100 year old report by the American Philosophical Society breaks down San Francisco’s serpentine by molecule but nothing specific around chrysotile.
There are already regulations on the books — the California EPA recommends that serpentine not be used to surface roads because the potential for asbestos dust but the risk seems to vary by location.
Senator Romero’s well-meaning but imprecise bill and statements have caused controversy amongst California geologists.
Geotripper extends Senator Romero’s overly broad statement to other dangerous state symbols:
California Poppies, our state flower, contain some morphine and codeine, the raw materials for making heroin, an illegal drug. Therefore “This bill is about raising awareness to protect the health of our citizens. California Poppies contain morphine and codeine, illegal drugs. Illegal materials have no place serving as emblems for the State.” Let’s get rid of poppies as our state flower…
Grizzly bears killed hundreds and hundreds of Native Californians and Mexican-Americans in the early history of the state. So… “This bill is about raising awareness to protect the health of our citizens. Grizzly bears contain teeth and claws, known killers of people. Toxic animals have no place serving as emblems for the State.” Let’s eliminate the California Grizzly Bear as our state mammal.
Oh, wait. We did one better: we eliminated the California Grizzly Bear instead. The last one was shot in the 1920’s.
I do not want to belittle the problem of asbestos, lung cancer, and mesothelioma. These are serious enough issues, but going after serpentine is misguided, and I believe, actually hurting the effort at raising awareness of the connections between the two.
Andrew Alden has more, including the potential legal consequences: (bold emphasize is mine)
As any geologist will testify, there is no such mineral as “chrysotile asbestos”; neither does serpentinite always contain chrysotile, which is not in itself asbestos.
I use the word “testify” because a legislatural finding has legal weight, and the mesothelioma legal industry is both wealthy and running out of legitimate victims to make money from. The old cases of heavy industrial exposure to powdered asbestos are near extinction. New cases will have to come from the far more nebulous situations where people in or near areas of serpentinite will claim damages purely from fear of “asbestos.” This is not at all unlikely. The legislature is about to make a mistake it will regret, and only the lawyers will benefit.
The bill has already passed the CA Senate, but has yet to be approved by the House or the Governor. (It already has a hashtag of #CAserpentine.)
But if they DO decide to spend time thinking about a new state rock instead of passing a budget, I hereby nominate chert.