Lead Poisoning

Although the use of lead as a paint additive has been prohibited by law since 1978, the abatement of lead-based paint, especially in older houses, continues to cost hundreds of millions of dollars a year.

The U.S. Department of Housing and Urban Development and state agencies have established regulations for abatement designed to minimize exposure to lead as it is being removed. Precautions include enclosing the area that is being worked on, using chemical strippers that reduce the production of lead dust and never burning lead paint with a propane torch because it creates toxic fumes.

Children under six years of age are of primary concern. Their developing brains and organs can be easily damaged by lead. Small children tend to put everything in their mouths, and anything containing lead, from small dust particles to large paint chips, can be harmful if swallowed.

More than 75 percent of all homes in the United States -- about 42 million pre-1975 dwellings, according to HUD -- contain lead contaminants. The U.S. Environmental Protection Agency estimates that 1.7 million children nationwide have unacceptable levels of lead in their bloodstreams.

Not all levels of lead indicate a hazard. Low-level lead-based paint on non- friction surfaces in a house where there are no children may not warrant any response, while heavily leaded paint in poor condition on the window of a child's bedroom is a hazard

Virtually all states have created tough lead laws based on federal rules mandated by Congress. The universally-accepted way to handle lead-based paint is to remove it, which involves moving the occupants for a period that could last weeks or months, because scraping, sanding and other removal methods generate great quantities of lead dust.

There are three basic tests, with two involving chemical analysis.

• The home testing kits are six-packs of sodium-rhodisinate sticks. Paint is removed from a surface and the stick is placed on the paint under the chipped surface. If there is lead present, the end of the stick turns pink. Testing is required on dozens of surfaces to ensure accuracy. The kits cost under $10.
• The other chemical test is called "atomic absorption" or "chip analysis," and often costs $30 a sample. Chips are taken from every surface in a house and sent to a lab for analysis.
• X-ray fluorescence scanning (XRF), which has become the most popular testing method, costs $350 to $500, depending on the size of the house. A three-bedroom city townhouse usually requires the taking of 150 to 175 readings, while the typical large pre-1978 suburban home requires 250 to 300 readings to ensure accuracy. The XRF test takes about two hours.

The cost of the work alone, aside from relocation expenses, is high. The EPA has estimated the cost of removal at $8 to $15 a square foot, or $10,000 a house.

Realizing that costs might be prohibitive for many people, the EPA came up with two alternatives. One is "enclosure," which means installing drywall or paneling over wall surfaces and replacing doors, windows, molding and trims.

The other is "encapsulation," which involves applying a paint-like coating over the lead-based paint. Surface preparation is similar to that used before applying ordinary paint, except that care is taken to avoid generating dust.

Encapsulants must pass rigorous federally established performance tests and be warranted for 20 years by the manufacturer. These encapsulants, which retail for about $35 a gallon, reduce abatement costs by about 80 percent, manufacturers say. Occupants of the house don't need to move while the work is being done.

While such encapsulants have been on the market for several years, their use has been restricted to licensed lead-abatement contractors. Recently, however, and with the approval of some state agencies, the encapsulants are being made available to homeowners and other do-it-yourselfers.

However, the manufacturers warn that encapsulating surfaces covered with lead-based paint may not be the correct solution for every house. Only proper testing by a licensed contractor can accurately determine the extent of the problem.

In addition, surfaces such as windows and doors are unlikely candidates for encapsulation. When you open and close a window, the friction created can wear down the coating quickly, exposing the lead surface underneath. Having the lead-based paint on windows and doors professionally removed, and then using the encapsulation coatings, is a better idea.

The encapsulants are typically "elastomeric," which means they have rubber-like properties that will return to its original dimensions after being stretched or deformed. Because the coating behaves like rubber, it will expand and contract with the surface to which it is applied.

Many encapsulants can be applied with an airless sprayer. Usually, however, the water-based coatings go on with a brush or roller. Often it takes more than one coat to reach the thickness on the treated surface necessary to effectively contain the lead-based paint underneath.

Some encapsulants, such as Fiberlock's Child Guard, contain an ingredient that makes the coating bitter to the taste. This is designed to keep curious children away from the treated surfaces without harming them.

The newer encapsulants are designed to be tinted to a variety of colors.

If the surface to be encapsulated is damaged, preparation work will be involved before the coating is applied. There are materials on the market designed to reinforce the walls in concert with the liquid encapsulant. These fiberglass materials -- Newtex is one example -- typically add 20 percent to 40 percent to the total encapsulation costs but are an inexpensive alternative to replacing a plaster wall, for example.

More information regarding lead abatement and encapsulation is available from HUD as well as state and local environmental protection agencies and health departments.

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