Asbestos and the Equitable Building: What’s all the excitement? Part 3

Health

Never buy asbestos quarry slaves. They die young.

Those words are attributed to Pliny the Elder (who walked the earth at the same time as Jesus); he was cautioning against buying the slaves used in asbestos mining. Thus, the hazards of asbestos were suspected 2,000 years ago. The 20th century has revealed supporting medical evidence and legislative actions with each decade bringing a more sophisticated understanding.

Asbestos exposure causes disease. How likely a person is to acquire disease as the result of exposure is highly dependent on the amount of exposure. Asbestos-related diseases have been seen particularly in workers with extended exposure to asbestos: shipbuilders, pipe fitters, those in construction and building trades, miners, auto service technicians, and their families. Many asbestos attorneys have gathered convenient lists of the professions most at risk.

You will find a summary of a 2007 peer-reviewed article in Journal of Toxicology and Environmental Health that reviews historical exposures to asbestos among skilled craftsmen from 1940-2006. You can find the complete article at Drake and read it free, but it will cost you $35 to access it on-line. It’s dry and technical but it is thorough, and it will tell you who has been exposed and to what extent.

A fairly short article from the Medical College of Wisconsin summarizes the health effects, extensively quoting Medical Professor Richard M. Effros. Here are some other links:

• Asbestos is toxic
• Asbestos causes cancer (human carcinogen)
• Asbestos causes asbestosis
• Asbestosis causes most mesothelioma
• Risk of asbestos related disease is compounded by smoking

The diseases caused by asbestos have a long period of latency. In medicine latency is the time delay between the beginning of a disease and the appearance of symptoms.

The issues of levels, exposure, and consequence are for the medical community, scientists, the Department of Labor, OSHA, EPA, legislators, and attorneys to sort out. I’d rather look at a little of the science.

How can asbestos be harmful?
Earlier we looked at two properties of asbestos that should be revisited when we talk about the potential harm of asbestos: friability (crushability) and steel-like durability. To these two properties we should add low density. Scientists define density as mass per unit of volume, but let’s try for something that gives us a physical picture of the low density of asbestos and how it can behave. Arizona road dust is about three times more dense than asbestos fibers.

With that picture in mind it is not hard to imagine asbestos fibers becoming airborne and not settling, which is what they do when disturbed by drafts, movement, crushing, breaking, foot traffic, sanding, etc. And the final property – the fibers are sharp, spiky little critters; about 1000 fit in the width of a human hair. (Photo 1, Photo 2 search for hair)

Now let’s bring back this idea of respirable – capable of being inhaled. Once airborne these microscopic fibers align themselves as air is breathed and go deep into the lungs.

To see a picture of what an asbestos fiber looks like when it becomes imbedded in the lung, go to an article called Clearing the Air in Harvard Magazine and find “asbestos fibers.”

The body has a pretty good set of trash incinerators with which it can get rid of most anything. One of them, a structure called a macrophage (the body’s own Pac-Man) will normally completely surround and enclose an undesirable material then release some pretty potent chemicals. These chemicals break down the undesirable material into small pieces that are carried away and excreted. Asbestos is problematic because many fibers are too long to be surrounded. The macrophage partially surrounds the fiber, releases its chemicals anyway and then the body’s own chemicals begin to act on normal healthy lung as well and begin to break down healthy lung tissue. The body can accommodate a certain amount of this type of chemical insult, but if there has been too much asbestos taken in, too much lung tissue is destroyed and disease results; that is something I don’t want to think too long or too hard about.

Is there any good news here? Sure. These are all questions open to medical and legal interpretation, but broadly interpreted: 1) It takes a long time to be affected by asbestos-related diseases. 2) One short intense exposure probably won’t harm you. 3) If you don’t disturb asbestos, you will be fine. 4) If you do disturb asbestos, your protection depends on following the recommendations.

In Part 4 we will see how our government tries to protect us as workers and individuals from exposure to asbestos.Related posts: Asbestos and the Equitable Building – Part One: What’s All the Excitement?, Part Two: A Short History of Asbestos

Credits: Photo on flickr by AndyRamdin

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.

[tags] Iowa, Des Moines, Central Iowa News, Asbestos[/tags]

Sandy Renshaw is Sandy Renshaw is a self-employed communications consultant. You will also find her blogging at Purple Wren.
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