By Leon Levine, Certified Industrial Hygienist
Reducing Lead Hazards in Older Homes – Introduction
Concerns of lead toxicity have been appearing more frequently in the news including the debacle in Flint Michigan and various schools testing for lead in drinking water. The greatest risk of being exposed to lead hazards for children is from lead chips and dust from lead based paint. The likelihood of lead-based paint and hazards increases with the age of the home. Houses constructed prior to 1960 have five to eight times the prevalence of lead hazards compared with homes built between 1960 and 1978. Overall an estimated 25% of the nation’s housing (or approximately 24 million housing units) has significant lead based paint hazards from deteriorated paint, dust lead, or bare soil lead according to a study by conducted by Jacobs et al. The presence of lead painted surfaces in the home does not necessarily signify a lead hazard. If managed properly the lead hazards can be minimized.
Lead in Paint
Lead is a soft, malleable heavy metal that was added to paint for several reasons. Different lead compounds were added to the paint as a pigment, creating a specific color depending on the compound used. For example, lead (II) carbonate, known as white lead, creates a white or cream color in the paint and lead tetroxide makes a bright red paint. Lead also reduces the time that the paint takes to dry, makes the paint more durable, and causes the paint to be more moisture resistant.
The sale of lead-based residential paint was not banned in the United States until 1978. The sale and use of leaded gasoline nationally in cars was steadily phased out over 25 years until its full ban in 1996. Lead is not banned for other uses and is still allowed for commercial uses. Today lead is commonly found in lead acid batteries, ammunition, solder, jet fuels, metal alloys, and radiation shields.
Lead Paint on Building Surfaces
Lead inspections can be conducted because of a property transaction when the buyer wants to know whether lead paint and hazards exist prior to buying a house or property. A lead inspection can be triggered when a child living in the home is identified with an elevated blood lead (>5 ug/dl). An insurance carrier may also require the homeowner to have a lead inspection especially when they are renting. Nurseries and day care centers may also be required to have a lead inspection performed to ensure children are not being exposed to lead hazards.
We have conducted numerous lead inspections in older homes to identify lead paint hazards and lead in drinking water and lead in soil in Connecticut, New York and New Jersey. Lead based paint has been found consistently in several building components including:
- Crown molding
- Decorative wood beams and columns
- Window sills
- Window Frames
- Door Frames
- Stairs (all components
Walls and ceilings have been found more often not to contain lead based paint especially dry wall or sheet rock. The prevalence of lead-based paint and hazards increases with age of housing, but most painted surfaces, even in older housing, do not have lead-based paint. It has been shown that between 2% and 25% of painted building components contain lead-based paint. The prevalence of hazards in housing in the Northeast and Midwest is greater than housing in the South and West.
Lead Exposure Risks
Federal regulations and guidelines are based on protecting children under the age of 6 years. The blood brain barrier has not developed in children under the age of 6, allowing lead to travel to the brain and cause toxicity. Children become exposed to the lead dust or paint chips when they crawl on the floor and then place their hands in their mouth, a behavior highly prevalent between ages 9 and 24 months. Chipping paint is concern, however many children are exposed to lead through the dust that originates from friction surfaces (doors, door frames, windows, window frames) painted with lead-based paint. Only a very small amount of dust (40 µg/ft2) dispersed around the floor of a home can lead to an elevated lead level in the child. Pica (eating nonfood items such as rocks, dirt, or paper) or chewing on lead-based paint on windowsills or interior woodwork also contributes to the child’s exposure living in a home with painted surfaces.
Managing Lead Hazards in Older Homes
The first step in managing lead hazards in older homes is knowing which surfaces are coated with lead based paint. Once the surfaces are identified through a lead inspection, proper control measures can be implemented. Any paint that is chipping needs to be corrected. Floors and surfaces need to be frequently wet wiped and/or vacuumed with a high efficiency particulate air (HEPA) filter. Options for managing lead based paint hazards include (1) paint removal through remediation, enclosing the paint with another material, removal of the building component (replacement with a newer component) or encapsulation with an EPA approved encapsulant. The least preferable control method is encapsulation, especially when dealing with friction surfaces because the surfaces are more easily prone to damage and chipping. The easiest control method is removal. For example a door or window can be replaced with a new model. Older windows also tend to be very leaky and much less energy efficient resulting in increased energy consumption. Also, prior to conducting any renovations, which may create and disperse lead dust, appropriate precautions need to be taken. EPA requires the use of a licensed lead renovator when lead based paint may be disturbed during a renovation or construction project. Lead abatement requires a licensed lead abatement contractor. Not utilizing a licensed contractor is illegal and can create significant lead hazards in your home.
In conclusion, homes prior to 1960 are likely to have 5 to 8 times the prevalence of lead hazards. However a study found that among homes built between 1978 and 1998, 3% (1,042,000 housing units) had significant lead-based paint hazards, but 7% (2,031,000 housing units) may have had lead based paint. This may be due to the use of left over paint or the reuse of old building components or imported building materials such as decorative tile. If managed properly, lead exposure risks can be significantly minimized. The first step in managing lead hazards in older homes is to conduct a lead inspection and being aware off all surfaces that are coated with lead based paint.
The certified industrial hygienists (CIH) and lead inspectors at ECOthink Group can assist you in successfully solving your lead hazards concerns and questions. Please email us at email@example.com.