Unless you headed back underground with the ground hog on February 2, you noticed asbestos in the news around Iowa this week: in The Des Moines Register; on WHO-TV; or as it was picked up from WHO by msnbc in two articles (1, 2), KCCI-TV, WOI-TV, WQAD in the Quad Cities, KPTM42 in Omaha. You might even have seen it on-line in the Quad City Times, The Creston News, the Muscatine Journal, the Worthington MN Daily Globe, the Waterloo Cedar Falls Courier, or heaven forbid the citation by the Oakland County MI Asbestos Lawyers Association or the New Jersey Asbestos Lawyers.
The genie is out of the bottle. Asbestos and the Equitable Building was big news, and it spread fast. Getting up to speed on why newscasters, lawmakers, law enforcers, scientists, universities, contractors, homeowners, real estate agents, and the general public would be interested in asbestos is not a short story, but it is pretty interesting. Thus, I would like to spend a few blogs sharing and linking a little of the information that is available - a short primer if you would. I intend to do this in five parts: what is asbestos? what is its history? is it considered harmful? what are some of the government regulations? and what is asbestos abatement? Through all five parts you will discover just who is concerned in Iowa, in the U.S. and around the world. Here we go.
Photo on flickr by Aaron Dan
Part 1. What is asbestos? How can a rock be airborne?
Faster than a speeding bullet, more powerful than a locomotive, able to leap tall buildings in a single bound? Nope. But asbestos survives unharmed by fire, can be woven into cloth, and can be described as stronger than steel. While that is not as good as Superman, it’s a pretty good start.
Asbestos is a mineral and a strange one at that. Rocks are usually made up of several minerals, but a few rocks are just one mineral. If you’d like to see photos of a few rocks and minerals, try this site from the University of North Dakota. Don’t worry, we’ll get to asbestos. A scientist would tell you that minerals have a definite chemical composition, and they would talk about which chemical elements were present, like lead and sulfur (found in galena over by Dubuque), silicon and oxygen (found in quartzite in northwest Iowa), or carbon, iron, and sulfur found in coal in central and southern Iowa. If you want to see other Iowa minerals, go to DNR’s site prepared by Jean Cutler Prior. The elements in the many individual minerals known generically as asbestos are mostly silicon, oxygen, magnesium, but often calcium, aluminum, iron, and manganese as well. These elements are common materials generally considered harmless on their own (unless you get hit in the head with a rock, of course).
Like other minerals it is a natural product that is mined. Major mines are found in Canada, South Africa, Australia with smaller mines along the East Coast of the U.S. and near Coalinga, California. Many other areas in the U.S. also have small mines.
On the outside chance that you are already so taken by minerals that you want to go a little further with minerals and see more photos, you can investigate sites at Bremen University in Germany (in English or German), or the University of Michigan (in English or Spanish).
But back to asbestos. The United States Geological Survey or USGS is a government agency. The USGS classifies six different fibrous minerals that are grouped under the term asbestos: chrysotile, crocidolite, amosite, anthophyllite asbestos, tremolite asbestos, and actinolite asbestos. The most common is chrysotile.
The three asbestos minerals most likely to be found in commercial products are chrysotile, amosite, and crocidolite. You can find lists of commercial asbestos-containing products on-line, but some of these lists are very misleading. For example, I found one list with the names of items that in years past were formulated with asbestos, but now these same products have no asbestos in them. Who needs that?! So stay away from those comprehensive lists. You’ll make yourself badly informed. We will look at a few specific products of significance in Part 2.
One of the nicest photos of asbestos the mineral is one from the State of Arizona. Take a look. There are a couple of features you should take note of. Unlike the other rocks and minerals, this example of asbestos looks like bundles of fibers. Exactly right. You can even see how they are lined up with each other. Some of this asbestos can be peeled away in fibrous bundles. It can be crushed between the fingers and reduced to a powder. The term for this reduction to powder is friable. We would also apply the term friable to soil. So, some asbestos is friable, and some is not, and friable asbestos is the most dangerous. Now friable is not a term we would normally associate with a rock or mineral, but it is a good descriptor of several forms of asbestos. Historically the more widely used more friable asbestos minerals were those classified as amphibolic. This class would include amosite and crocidolite (but not chrysotile).
Imagine then, if you would, crushing, grinding, hammering, rubbing, sanding or otherwise breaking materials containing friable asbestos. These processes can release asbestos fibers from the surface. As this happens some of the fibers become airborne. Some fibers or bundles of fibers can be seen and look a little like dust, and some cannot be seen with the naked eye. The dusty fibers get airborne, resettle to the ground, only to be picked up again by wind, drafts, motion, shoes, brooms, sweepers, or vacuums. They may get broken into smaller pieces, and they keep moving. Some of the asbestos pieces are big enough that if we breathed them, they would catch on the membranes in the nose and throat and be sneezed or coughed out. Others however are called respirable, meaning that they make it into the lungs. And here comes the rub. Just how big are these respirable fibers? The answer to that is: pret-ty darn small. Wikipedia (not always a perfect source of information, but generally pretty reliable) has a section of an article on asbestos that talks about the size of respirable asbestos fibers. (Go to the part of the article labeled “Asbestos as a contaminant.”) They point out that you could take anywhere from 1,000 to 10,000 respirable asbestos fibers and line them side by side in the width of a human hair. (Don’t try this at home, and if you do, don’t sneeze. You’ll have to start over again.) Naturally you can’t see these respirable fibers with the naked eye, but the Wikipedia article has an interesting picture taken with a scanning electron microscope (SEM). That photo gives you a pretty good picture of what they look like. Notice the spiky quality to the fibers. This will be important later.
Well, now you have some idea of what asbestos is, where it comes from, and some of its properties. I’ll be back with a little history, but I have to go back to work.
Guest Writer: James G. Lindberg (Jim) is the Purple Wren’s sweetie and is a visiting chemistry professor at Grinnell College and retired from Drake University.
Technorati Tags: Iowa, Des Moines, Central Iowa News, Asbestos, Equitable of Iowa, Minerals, Mining
Our Brand is Crisis will be shown at the State Historical Museum on Thursday and on Saturday. Cost is $5, or $4 with donation of a canned food product for the Food Bank of Iowa. The documentary follows political consultant James Carville and his partners as they work on the 2002 campaign of Gonzalo “Goni” Sànchez de Lozada, a candidate for president in Bolivia. If an indoor activity is needed on Sunday, the Grand Canyon Adventure is still playing on the IMAX at the Science Center. Plus, there is always live theater at the Des Moines Playhouse with Sarah, Plain and Tall.
