Tuesday, January 31, 2006

Kennedy sees the Light...



...on asbestos.

Kennedy's bit of sarcasm at the filibuster hearings:

"What's the next measure on the calendar? Asbestos? Isn't that interesting?"

As a pool guy and a geology school drop-out, I have an iron in this fire. Here are the facts on the over reaction concerning asbestos.

Asbestos is general term for a rock mineral that splits into small fibers. It's fibers are heat resistant, flexible, chemically inert, and non conductive. Needles to say, it's cheap and useful for tons of stuff. There are several types of asbestos producing rocks, just as there are several types of granite, each with somewhat different properties. There are four types of asbestos mined by industry, but for the sake of space, I'll talk about the two most widely used.

Asbestos fibers classified as either amphiboles or sepentine Amphibole fibers are dangerous because they consist of long, barbed fibers, and when inhaled, latches onto lung tissue and causes scarring and eventually can cause cancer. No dispute here. Fibers from the Crocidolite mineral, found and mined in South African mines are among the most dangerous. Some South African miners developed mesothelioma within a year of exposure.

The main North American fiber type, the sepentine Chrysotile, are short and curly with fewer barbs on the fiber. Because of their shape and physical properties, the Chrysotile fibers, if inhaled, are easy for the lungs to expel. This cheaply locally obtained material has, in the past, been the predominant type used in the Northern Hemisphere, and accounts for almost all the asbestos used world wide (about 90 – 95%) today. The major source of Chrysotile has been regions in Canada, and much of the research on Chrysotile comes from those mining regions.

Though there are dangers to excessive asbestos exposure, regardless of type, the EPA got the asbestos scare rolling by grouping ALL forms of asbestos together and using rubrics weighted heavily toward results of Crocidolite / cancer associations. Here is another example of the same distortions. Note this article gives a 10 to 20% increase in mesothelioma. Here is a description of the environment in the town some thirty years ago:

”Every day, twice a day, she swept the front steps, because every day, twice a day, a layer of white dust an inch thick would accumulate. “

In this environment described, you would expect the disease rates among miners and their families to absolutely soar. But this study study shows the assersions made in the previous link are false. It relies on a non-scientific paper to substantiate its claims. Long term studies indicates Chrysotile miners have only a slight increase in asbestos related diseases (see paragraphs 3 and 4 for a rebuttal of the EPA's methodology).

Chrysotile is even naturally occurring in the environment. From the National Office of Pollution Prevention - Canada:

...it is present in two thirds of the rocks that make-up the earth’s crust. As a result of bedrock erosion, by way of water and wind action that liberate chrysotile fibers from the rock, we are environmentally exposed to chrysotile fibers. Irrespective of where we are on earth we all breath an average of 10 000 to 15 000 chrysotile fibers every day. Potable water contains an average of 200 000 to 2 million chrysotile fibers per liter, and can reach up to 170 million fibers per liter in chrysotile producing areas in Quebec.

Am I trying to convince anyone that asbestos is just fine, and people shouldn't sue companies that knew of risks and didn't act to minimizes those risks? No. But despite all this information showing an over-inflated risk assessment concerning asbestos, and that most asbestos producing companies have been litigated out of business, and that most of those dangerously exposed have died, the lawsuits go on. Here is more information on asbestos litigation (while I'm typing this, a commercial ran promoting the fight against unfounded asbestos litigation).

PS. Asbestos fibers interlock with each other, trapping air within the lattice of fibers, which it works so well as an insulator. This also means that asbestos placed between two sealed walls stays there. So when we find asbestos insulated schools, what do we do to “Protect The Children”? We go in and knock down those walls, which, despite best efforts, sends “dangerous asbestos” flying everywhere exposing everybody. And the calculated risk of death linked to school based asbestos exposure is somewhere around 0.005 - 0.093 per million. Compare that to these risks; death from Whopping Cough vaccine 1 - 6 per mil., death from drowning 27 per mil., and long term smoking 1200 per mil. Go figure.

PPS. Why, you may ask, would being a pool guy make me care about asbestos? Because pool plaster used to be mixed with asbestos as a bonding agent until the late 80's (not sure on the exact cut-off date). I have seen many 40 to 50 years old pools with the original surface that has no blistering, while modern plaster pools often will start to blister after only 10 to 15 years.

1 comment:

Michigan-Matt said...

I enjoyed the post, Michael. Nicely done.