products, from spray-on fireproofing, sound proofing,
piping and vessel insulation, vinyl asbestos floor tiles,
ceiling tiles, and some types of shingles, to ironing
board covers. When asbestos-containing materials become
friable (that is, powdery or easily crumbled), dangerous
asbestos fibers may be released into the air. The fibers
can then be carried through the entire building by way of
the ventilating system. Whenever the presence of asbestos
is suspected, it should be reported and tested
immediately. Coordinate with the base asbestos control
program to determine treatment.
Asbestos can only be positively identified by laboratory
tests of samples. There are some clues to watch for,
- Insulating coatings on old boilers: Off-white,
smooth-surfaced, usually cracked.
- Cloth-wrapped steam and hot water pipe lagging,
especially if the edges look like light-gray
- Asbestos paper on heating pipes, forced-air ducting,
beneath asphalt and linoleum flooring, behind
kitchen wallpaper: off-white, usually textured,
- Asbestos-cement shingles used to re-side older
framed houses from the 1930s through the 1970s: any
color, cracked and chipped along the edges in
high-traffic areas. Asbestos-cement roof shingles
used from the 1940s through the 1960s: usually gray,
often with brownish-white streaks in areas where
water stands, very hard (pebbles tossed against them
make a pinging sound).
- Asbestos-cement board: usually gray, 1/4-3/4" thick,
brittle, easily broken, often found on joists above
a furnace or boiler, around and beneath wood stoves,
behind ceramic tile in a bathroom.
o Radon. Radon is a colorless, odorless, radioactive gas
that occurs when uranium, a natural element, breaks down.
Public Health Service studies have shown a link between
some types of cancer and long-term exposure to radon gas.
Buildings in areas where the earth contains large uranium
deposits are more likely to have radon contamination.
Since radon rises through the soil, it is most often found
in basements, but it can be distributed throughout a
building by the ventilation system. Old houses actually
are somewhat less likely than newer ones to have radon
contamination above the basement level because they have
more cracks and better natural ventilation. Detection
kits containing charcoal filters can be used to test for