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Read About Scars In An Upside-Down Tree
By asbestoshub | December 31, 2008
An intriguing entry in Effect Measure in ScienceBlogs.com speculated that Asbestos is responsible for one of the greatest occupational health catastrophes of the 20th century. A new report from CDC assures us it’s still with us and still killing people.
Nineteenth-century asbestos advertisements pitched asbestos as a product to save the boss money. Too bad it also killed his workers. In the twentieth century, when the safety movement pushed for standard brakes on cars, that need was met with asbestos brakes and clutches.
Most everyone knows that asbestos can cause several kinds of cancer but fewer realize the most characteristic disease from inhaling asbestos is a scarring of the lungs that takes its name from the only thing that causes it: asbestosis. This disease has been evident from the earliest days of the asbestos industry and it was generally accepted as a serious occupational disease by doctors no later than 1930. The fact that we killed hundreds of thousands of workers from asbestos after that date should be an everlasting shame.
Think of your lungs as sort of an upside down tree. The trunk is your windpipe that has two big branches to your right and left lungs. These branch in turn, again and again until we get down to the tiny twig level. The lung branches don’t conduct sap like in a tree. They conduct air and this whole branching system is also called the conducting system of the lung. It conducts oxygen from the outside down to your blood and carbon dioxide from your blood back to the outside. How does it get to the blood?
At the very tips of the tiniest twigs we have the counterpart to the tree’s leaves, a tiny sac of delicate tissue intwined through which are the body’s tiniest blood vessels, the capillaries. The tissue here is so thin and delicate that gas molecules can pass back and forth between the blood and the hollow sac they enclose and that’s how oxygen move back and forth from the “outside” to your blood. This tissue is so delicate it has to be protected and there are a number of defense mechanisms to guard the business end (the gas exchange system) from dirt, bacteria, viruses, etc. One kind of defense involves a kind of wandering police force, immune system cells called pulmonary alveolar macrophages. Macrophage means large eater and that’s what these cells are. When they see a bad guy they engulf it and once engulfed they have little bags of enzymes in side that digest it. Jaws.
But not everything is easily digestible. When a macrophage encounters an asbestos fiber it tries to eat it but the fiber proves to be tougher. Hey, asbestos resists fire and acids and corrosives. Is a little blood cell going to bother it? No. In fact the blood cell gets the fatal end of the deal. The fiber kills the macrophage which dumps all its digestive juices into the surrounding tissue, causing a tissue reaction. This reaction eventually scars. A scar is fibrous connective tissue. Now imagine where this is taking place, at the ends of the lung tree. Imagine now the space between the leaves and the twigs and the branches. That’s called the interstitial space and that’s where the scar tissue is being laid down: interstitial fibrosis. It’s like encasing the lung in a thin fibrous net. The scarring does two bad things. It makes it more difficult for gas molecules to move back and forth from lung to blood (this is called a conductive defect). It also restricts the lungs motion. This is a restrictive defect. The restriction means you can’t take deep breaths, only shallower and shallower ones, and the conductive defect means even the shallow breaths aren’t as effective in exchanging gas.
The scarring process takes a long time, usually somewhere from 10 to 40 years of reasonably heavy exposure to asbestos. And your lungs are a wonderful device and they have a lot of reserve capacity. You have to destroy 80 - 90% of their function before the signs and symptoms of the scarring start to appear, although the disease is visible on x-ray earlier. In the terminal stages of asbestosis the worker becomes a pulmonary cripple, unable to even get out of bed because the exertion is too great. Then the disease ends fatally.
Plenty of young workers are still dying from asbestosis, according to an estimate that just came out from the CDC.
Asbestos fibers in a lung are a delayed action time bomb. We’ve made progress in getting asbestos out of our workplaces and environment, but there is plenty still in place — think schools and hospitals — and still asbestos products like brakes. Construction workers are exposed during demolition and rip out of asbestos-containing building materials and pipe fitters and insulators still work around asbestos insulated facilities installed decades ago.
The only magic asbestos performed was to turn broken bodies and lives into dollars for asbestos companies, who knew all along the damage they were doing. And the damage still goes on.
Visit Scars in an Upside Down Tree, it’s a great entry.
Topics: Claims, Exposure, Facts, Law |
