Lead paint is a toxic substance that owners of older homes should be aware of and take appropriate steps to either contain or remove. Lead was used as a pigment and drying agent in alkyd oil based paints, latex water based paints generally have not contained lead. Because of the popularity of alkyd paints in the 1940's through the 1960's, there are many sources for lead exposure in a household. Primarily, deteriorating lead paint surfaces and lead dust are attributed as the most common cause of lead poisoning. Exposure is also possible from lead in water, in food, lead glazed ceramics, lead paint on toys and in art paint. Because the symptoms of poisoning from lead based paint can be subtle and difficult to diagnose, it is important to test for lead paint if the house was built before 1978 and contains peeling or flaking paint.

Lead paint is a neurotoxin. It effects all of the bodies systems except for pulmonary where it can pass straight through lungs. The greatest effects are to the Central Nervous System via the Circulatory system as well as through absorption into the bones. in people with iron and/or calcium deficiencies, the uptake of lead into the system is exacerbated. The effects from lead exposure vary according to duration and quantity of exposure. Because it directly affects the Central Nervous System, lead can precipitate a variety of ills including: High blood pressure, mood changes, headaches, digestive problems, nerve disorders, muscle and joint pains, kidney damage, suppressed libido, and even the lowering of sperm count. The current blood lead level which defines lead poisoning is 25 micrograms of lead per deciliter of blood.

Because children have a higher metabolism, the lead can be absorbed into the system much quicker and create serious problems. Brain damage, retardation, slow mental development, irreversible learning disabilities, reduced IQ, attention deficit disorders, hyperactivity, damage to kidneys, liver and permanent neurological damage are all possible from exposure to lead.

Before the health effects of lead paint were known, lead paint was considered one of the best means of protecting against weathering of exterior surfaces. According to the Maryland Department of the Environment, 61%' of all painted exterior areas contained lead paint before 1940. In high quality paints, concentrations of 40-60% lead was not uncommon. Figure 1 shows a statistical breakdown of lead painted surfaces on house components from the late 1970's back. Because of its' corrosion resisting qualities, lead paint was most commonly used around windows (to seal wood trim) and on railings to protect subsurfaces. Lead paint was also painted on a variety of sidings and brick walls for added protection from the elements. On clapboard shingle siding and on painted brick, of lead paint oxidize and break down. If an off-white to white chalk is noticed on these surfaces and the house was built before 1978, appropriate steps should be undertaken to test whether it contains lead.

Inside of older houses (pre 1978) peeling paint around radiators and windows could very possibly contain lead paint. Lead paint was commonly used to paint radiators as it was not affected by the heat being released. Many older homes may have radiators that have the original paint. If it can be determined whether it is original paint, it is highly recommended that it be tested, especially if the paint is flaking or peeling. There are three commonly used methods to test lead paint one of which the home owner can utilize as an indicator as to the presence of lead in the paint.

"Over the counter" lead paint test can be purchased from hardware stores and paint stores. Most of these test kits contain sodium sulfide solution which darkens if lead is present. The darker the color the more concentration of lead. These test are fairly inexpensive and can give clues as to the possibility of lead paint. Unfortunately, the accuracy of these kits can vary due to other metals causing false positive readings as well as resins in the paint masking the lead, preventing the sodium sulfide from reacting with it. In addition, dark color paints may camouflage the test results as well as many coats of paints hiding the base coat of lead paint. At this time, these tests have not been evaluated by the U.S. Consumer Product Safety Commission so they have not taken a position in regards to accuracy. It should be noted that the Maryland Department of the Environment uses these tests as an indicator for the presence of lead paint. There are two other tests that are more accurate but they require professional analysis of the sample.

An X-ray Fluorescence machine is a portable machine that can measure lead content in-home. Because the machine contains radioactive materials, the person conducting testing should be a licensed professional with the state work is being conducted in. These machines are convenient because they give readings on-site, with little or no turn-around time. The down side is that the machines will not read accurately on surfaces such as brick, metal and radiators. As such, it is recommended that the operator be questioned as to the percentage of error for each surface tested that is being tested so that a true test result may. be deduced. Be sure that at least three readings are conducted for each surface. If the results fall between the 0.5 mg / cm2 and 2.0 mg / cm2 using the XRF, paint chip analysis should be done for confirmation. 0.7 milligrams or more per square centimeter is considered to be lead paint in many states.

The final testing protocol requires the collection of a paint scrapping which is then sent to a lab for analysis. This is considered the most accurate of the three although it is also the most time consuming as well as an invasive test. A home owner or qualified collection individual may collect the sample. If the home owners decides to collect the sample, most testing companies or labs will supply the necessary plastic bags or containers in which to place the sample. Paint containing 0.5% or more by weight in dried solid (also reported as 5000 milligrams per kilogram) is considered lead paint. Following are the steps that a home owner would follow if they choose to do the sampling on their own.

• Obtain sample container from testing company or lab of choice. Label container with consumer's name and address as well as specific location that each sample was scraped from. (For greater accuracy, several samples should be taken from each suspected area.)
• Using a sharp knife or chisel (flat end up) cut through the edges of the sample paint. The company should specify how much it needs to conduct the test but normally a 2" x 2" sample will suffice.
• Lift off the paint with a clean, putty knife and put sample into the container. Be sure to take a sample of all layers of paint as the lower layers may contain the lead. It is important NOT to get any of the bottom surface i.e. wood, plaster, metal, or brick with the paint sample as it can adversely affect the results.
• Wipe the surface and any paint dust with a wet cloth or paper towel and discard same.

According to the U.S. Department of Housing and Urban Development (HUD), if the results show a lead in pain percentage greater than 0.5% by lab testing of greater than 1.0 milligrams per square centimeter by X-Ray Fluorescence, actions to reduce exposure should be taken. It is especially important when the paint is deteriorating or when pregnant women, infants or children are present. Depending upon the condition of the paint and economic considerations, there are different steps that can be implemented to reduce lead paint exposure in the house.

Before executing any repairs, it is important to remember that lead paint dust is a hazardous substance. Exposure to lead paint dust should be kept to a minimum and steps need to be taken to control and contain the lead dust. The following are steps that can be taken to reduce the risks of lead paint in the home.

1. Replace the lead painted item.

Items such as doors or other easily removable objects can be removed as long as the removal can be done in a matter that will keep the level of lead paint dust to a minimum. If the item cannot be removed easily or the removal will create lead paint dust, a professional should be called.

2. Cover the lead-based paint.

The surface can be covered gypsum wallboard or can be sprayed with a sealant. It should be noted that these are not long term solutions. It is possible that the lead-based paint will continue to loosen lead paint dust or partially mix with the new paint allowing lead paint dust to be released when the new paint deteriorates. Sometimes it is even possible just to flip the surface over, caulk and paint it to seal in the lead paint.

3. Have the lead-based paint removed.

Professionals trained and certified in the remediation or removal of lead paint can be called to execute the removal. Professionals have a variety of means available for removing the lead paint including: sanding with sandpaper, scrapping, chemicals, sandblasters and torches or heat guns. All of these methods can produce lead fumes or dust that can be inhaled or ingested. Wet methods help reduce the amount of lead dust but can release lead laden water into the environment. It is important to make sure the professional is containing the lead paint dust. Even if the work only involves removing a surface and treating it outside of the house, the process of removing the surface may release lead dust. Because every house is different, it may be advisable to consider not living in the house while this process is occurring. Consult professional opinions before making this determination.

4. Reduce lead dust exposure.

Periodic wet mopping and wiping of surfaces and floors with a high phosphorous cleaning solution can remove lead paint dust. This can be achieved by mixing one tablespoon of electric dishwasher detergent (at least 5% phosphate) with one gallon of hot water. Wear waterproof gloves to prevent skin irritation. This is a preventative measure and is not an alternative to removal or replacement. Avoid activities that will disturb or damage lead based paint and create dust.

5. Test dust for lead content.

It is possible to test dust for lead content. Areas like window sills and floors are especially easy to test. Sampling the dust is done with a wet nap (like one would find in a restaurant). The lab then measures the nap and can report on the lead content of the dust. When repairs or work is done in or around an area suspected of containing lead, this test should be administered either by the home owner or a professional testing company. In either case, it is important that the wet nap may be exposed to any other debris or dust so that an accurate reading can be obtained (we recommend placing the sample in a new zip-lock bag, labeling room and location). Following are the acceptable levels for lead per square foot of surface area. Floor, below 200, Window sills, below 500 and Window wells, below 800. Readings above this indicate elevate lead levels.

There are certain steps both the home owner and the professional lead removing company should follow when doing any work around the home.

• Home owners should keep children and other occupants (especially high risk people like pregnant women and those with blood pressure) out of the work area until repairs are completed.
• All food and eating utensils should be removed from the work area.
• Contractors should remove all furniture, carpets, and drapes and seal the area where the work is to be done from the rest of the house. The floor should also be covered and sealed unless lead paint is being removed from it. No eating or drinking should be permitted in the work area cabinets and food contact surfaces should be covered and sealed.
• Contractors should either dispose of or launder separately clothing worn in the work area. Workers should not wear the clothes into other areas of the house.
• Debris should be cleaned using special vacuum cleaners equipped with HEPA (high efficiency particulate air) filters and should use a wet mop after vacuuming. Because lead is a hazardous Material state and local regulations must be obeyed in regards to proper disposal.

Although lead paint is being found with less frequency as older homes are being replaced or upgraded, it is still prevalent especially in urban area. Because lead paint is dangerous do not take any chances, if you suspect it, test for it. Below is a list of numbers of both Federal and State agencies that can provide more information regarding lead in paint.