On June 9, 2009, Acting Surgeon General Steven K. Galson, MD, MPH, issued The Surgeon General’s Call to Action to Promote Healthy Homes. The Call to Action tackles a host of safety issues in the home, from falls down stairs to burn injuries to drowning in bathtubs. It also tackles important environmental issues, including lead and radon, issues that are near and dear to my heart. So, I thought in this 5 part series we could tackle some of the environmental issues that affect your home, and identify simple steps to reduce or eliminate exposure. As the Call to Action states, healthy homes lead healthier lives.
So, let’s talk about lead first.
Lead remains an environmental contaminant in our homes, a toxic legacy mostly from lead use in paint. Other sources of lead in the home include lead water pipes and solder used in plumbing; brass faucets, particularly older, imported brass faucets; toys; jewelry; ceramics; herbal and folk remedies; and more. Many of us dismiss the risk of exposure to lead, believing that the ban of lead in paints and gasoline have solved the problem. But, lead remains, even today, the number one preventable childhood environmental poison.
Children are particularly sensitive to lead exposure because of their smaller size, greater rate of lead absorption, and ongoing development. Since the 1970s, because of a number of regulatory programs, the average blood lead levels (“blls”) of US children have declined significantly, almost 80%. But, children are still exposed to lead. More importantly, new data indicates that blls once believed to be safe are not. Several recent studies indicate that children with blls at 2.0 ug/dL exhibit adverse health effects (well below the current “level of concern” of 10 ug/dL). Studies suggest a significant loss of IQ occurs in children with blls less than 7.5 ug/dL. Keep in mind that 1 out of every 10 US children has a blood lead level above 5 ug/dL.
Many moms have told me that they don’t have to worry about lead because they live in a “nice house” and their children don’t “lick the walls.” But lead exposure isn’t about living in a nice house or not eating paint chips. HUD estimates that 25% of the nation’s housing stock contains significant lead based paint hazards.
We are exposed to lead primarily by ingestion and inhalation. Children are more likely to engage in activities that can lead to lead exposure, such as mouthing activities. Video studies of young children demonstrate that they put objects into their mouths more than 20 times per hour. If dirt on their hands or those items contains lead, children will get a shot of lead each and every time they engage in mouthing activities. In fact, thumb-sucking and other hand-to-mouth behaviors may account for as much as 80% of child lead-related exposures. On average, children under six will retain about 50% of the lead that reaches their digestive tract, and will also retain about 50% of the lead that they inhale. In comparison, adults only absorb about eleven percent (11%) of the lead they ingest.
We get lead in our homes primarily from lead based paint, which was used up until 1978, when the residential use of lead based paint was banned. Lead may also be found in varnish or wood surfaces in older homes. Although lead has been banned in paints and varnishes, the it persists in our homes, day care centers, churches and schools. Both lead from paint chips, which you can see, and lead dust, which you can’t always see, can be serious hazards.
What’s the risk of lead being in your home?
- A house built before 1940 has an 87% chance of containing lead based paint.
- A house built between 1940 and 1959 has a 68% chance of containing lead based paint. •
- A house built between 1960 and 1977 has a 24% chance of containing lead based paint.
Lead paint chips from peeling paint are one source of lead, but so is lead contaminated dust, created as painted surfaces wear over time, particularly where painted surfaces rub together, such as doors, windows, and built in cabinets. We also track into our homes lead contaminated dirt from outdoors. One study found that 85% of the dirt in our homes comes from outside. That contaminated dirt then falls off of our shoes and onto our floor coverings and collects as dust in our homes.
Household dust levels of lead have been shown to be an accurate predictor of a child’s blood lead levels. The higher the lead dust lead levels, the higher the child’s blood lead level. For reference, a child’s blood lead level can rise 1 to 5 micrograms lead per deciliter of blood for every 1,000 ppm increase in dust lead. The EPA’s safe guideline for lead contamination in dust resulting from lead-based paint hazards is 40 micrograms of lead per square foot of floor (ug/ft2). But, according to the American Academy of Pediatrics, 20% of children exposed to floor dust lead levels of 40 ug/ft2 will have a blood lead level in excess of 10 ug/dl.
What can you do to make your home healthier and reduce the risk of exposure to lead? Come back tomorrow to find out.
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