The Asbestos Picture

Picture Asbestos in Home Air: Little Arrows

We are repeatedly told that chronic low levels of toxic substances are "safe." We need not fear health effects related to asbestos exposure unless long term occupational hazards are present.

Little Arrows
"There's a boy, a little boy
Shootin' arrows in the blue
And he's aiming them at someone
But the question is at who
Is it me or is it you
Hard to tell until you're hit
But you'll know it when they hit you
'Cause they hurt a little bit"

Little Arrows
Leapy Lee, 1968 pop hit

The purpose of Air-Purifier-Power is to promote the "unscientific" notion that some health is sacrificed with every toxic exposure, no matter how small. Be afraid, be very afraid.

The asbestos debacle is perfect illustration of my theme: "What you can't see does hurt you." It is difficult to get the big asbestos picture because the problem is so widespread. When you choose a place to live, lease an apartment, or buy and sell real estate, an asbestos risk is assumed. Increasingly, environmental aspects cloud every real estate transaction. For anything built before the mid 1980's a competent inspection should include air quality testing, including asbestos testing.

In Europe, a homeowner is liable for asbestos on her property, and subject to extensive regulation when it is discovered. This has not happened in the US yet, but it will. As I write, a controversial French ship is sailing for India loaded with toxic waste. Protestors plan to try to block unloading. Can you guess what fiber (45 tons) accompanies the PCBs, dioxin, and other sludge?

Asbestos?

Yep.

Help, I'm a Rock

"Asbestos" is a generic commercial name for a group of six very durable, finely fibrous, hydrated silicate minerals. Rocks.

Made of magnesium, silicon, hydrogen, sodium, calcium, iron, and oxygen, they feature positively charged metal ions whose outer shells are hungry for electrons.

All this fuss about a rock?

I'm afraid you're right.

The discovery of Radon in homes has taught us that even rocks can be dangerous. This rock, asbestos, has unique chemical structure that looks like clusters of fine threads. It breaks easily, but only in one direction, forming needle sharp strings which can be woven into fabric, yarn, or rope. Ground finer it can be mixed into thousands of commercial products.

Asbestos is mined just like any other mineral. Principal deposits are located in Canada, the former Soviet Union, and South Africa. The fibers cannot be easily destroyed: they resist high temperatures, chemical decay, and oxidation. A poor conductor, it is a perfect electrical insulator. Fibers can incorporated into materials as different as cotton and cement.

Asbestos in the Home: Little Arrows Everywhere

These thin, flexible strands break down into strings 1/1000 the diameter of a human hair. Picture asbestos like a steel wool scrubbing pad, only thousands of times smaller. The material tends to retain its aspect ratio, the long thin profile, even when worn down into fibrils so small they can be positively identified only with a transmission electron microscope.

asbestos picture Here are the fine particles your mom didn't warn you about. These minerals can break into fibers measuring from 0.1 to 50 micron in length, and as thin as 0.01 micron. (1 micrometer, or "micron”, is 1 millionth of a meter, about 1/10 the size of a human cell) These are incredibly fine needles, small enough to be scalpels used for surgery on the genetic material (DNA) inside human cells. Very little arrows.

This "asbestiform" shape, three or more times as long as it is wide, poses unique challenges to our immune systems. It is also a challenge to the average air purifier. Careful readers will recall that the HEPA filter standard calls for 99.97% removal of particles .3 microns in size. HEPA spec is focused at .3 microns because it is the most penetrating particle size: larger and smaller particles are easier to capture. Some asbestos particles are just this length. As detailed throughout this site, many air cleaning machines fail to achieve the HEPA goal consistently.

Fortunately, it is longer strands in the 10 micron range which last longer than our lungs. A decent HEPA air purifier will collect these. This is one reason why bypassing, sub-micron efficiency, and smaller room size recommendations are featured here. Even if my home is not badly contaminated, I don’t want to breathe these little arrows of asbestos.

An asbestos fiber can be the source of hundreds of much finer fibers over the course of time. These fines entrain with every draft, floating for days in the air we breathe. Asbestos is not biodegradable on any humanly relevant time scale. Natural decay of rocks adds to the increasing aerosol burden of toxic fibers of many types, both indoors and out.

Even for those not subjected to chronic asbestos, and never develops asbestosis or related asbestoses (asbestos related diseases), this trace background level is still an immune system burden.