Lead has long been recognized as a harmful environmental pollutant. In late 1991, the Secretary of the Department of Health and Human Services called lead the "number one environmental threat to the health of children in the United States." There are many ways in which humans are exposed to lead: through air, drinking water, food, contaminated soil, deteriorating paint, and dust. Airborne lead enters the body when an individual breathes or swallows lead particles or dust once it has settled. Before it was known how harmful lead could be, it was used in paint, gasoline, water pipes, and many other products.
Old lead-based paint is the most significant source of lead exposure in the U.S. today. Most homes built before 1960 contain heavily leaded paint. Some homes built as recently as 1978 may also contain lead paint. This paint could be on window frames, walls, the outside of homes, or other surfaces. Harmful exposures to lead can be created when lead-based paint is improperly removed from surfaces by dry scraping, sanding, or open-flame burning. High concentrations of airborne lead particles in homes can also result from lead dust from outdoor sources, including contaminated soil tracked inside, and use of lead in certain indoor activities such as soldering and stained-glass making.
- Asbestos is a naturally occurring mineral fiber that can be positively identified with a special type of microscope.
- Several types of asbestos fibers exist. The most common building material is chrysolite.
- Breathing asbestos fibers at high levels over an increased period of time can increase the risk of:
- Lung cancer.
- Mesothelioma, a rare cancer of the thin membranes lining the lungs, chest, and abdominal cavity.
- Asbestosis, a non-cancerous lung disease related to diffuse fibrous scarring of the lungs.
- The symptoms of these diseases may not appear for 20 to 30 years after the first exposure to asbestos. However, some medical journals have published reports linking some mesotheliomas to short exposure periods (i.e., months).
- Most people with asbestos-related diseases were exposed to elevated concentrations on the job. Some developed disease from exposure to clothing and equipment brought home from job sites.
- The risk of lung cancer and mesothelioma increases with the number of fibers inhaled.
- Cigarette smoking significantly increases the risk of lung cancer for people exposed to asbestos.
Where is asbestos found?
- Asbestos is most commonly found in homes that were constructed before the 1970s.
- In older homes, asbestos may be found in:
- Roofing and siding shingles made of asbestos cement.
- Old insulation.
- Texture and wall paint and patching compounds used on walls and ceiling joints.
- Artificial ashes and embers used in gas-fired fireplaces.
- Older products such as stove-top pads.
- Paper, millboard, or cement sheets used to protect walls and floors around wood-burning stoves.
- Vinyl floor tiles and the backing on vinyl sheet flooring and adhesives.
- Insulation for hot water and steam pipes.
- Insulation on oil and coal furnaces and door gaskets.
- Vermiculite attic insulation.