from low birth weight, impaired hearing, and altered gestational age, which can lead to further 
complications. 
In addition to damaging the nervous system, elevated blood lead levels can also affect the kid¬ 
neys and reproductive system and cause high blood pressure. Very high levels (greater than 80 
g/dL) can cause convulsions, coma, or death. Levels greater than 150 g/dL are fatal if not 
treated quickly. Fortunately, exposures resulting in such high levels of lead are rare. 
2.2 Sources of Lead in Dust 
Lead dust from deteriorated paint is the most significant contributor to childhood lead poison¬ 
ing. 1 While the use of lead paint in residential buildings was federally banned in the United 
States in 1978, many homes built prior to 1978 still contain lead-based paint. Paint used in 
homes built between 1950 and 1978 contained between 0.5 and 50 percent lead, and the paint 
used prior to 1950 contained higher concentrations. One estimate is that more than 3 million 
tons of lead-based paint remain in the 57 million homes built prior to 1980 2 . 
Lead dust forms as lead-based paint peels, chips, chalks, or cracks. Dust also forms when paint¬ 
ed surfaces bump or rub together (called friction surfaces, particularly found on doors and win¬ 
dows). The primary sources of lead dust are interior painted building components that receive a 
lot of wear-and-tear: windows, trim, and sills; doors and door frames; columns, stairs, railings, 
and banisters; and porches and fences. Lead dust can also form when lead-based paint is dry 
scraped, dry sanded, or heated during building renovations. Lead dust is especially problematic 
when found on surfaces that children can reach and chew or mouth, such as window sills, rail¬ 
ings, and stair edges that are at child height. Another important source of lead dust is lead that 
has been deposited in soil. Lead in residential soil comes from several different sources, includ¬ 
ing lead-based exterior paint. Before 1978, lead paint was widely used on the exteriors of resi¬ 
dential and other buildings. As the paint on a building s exterior deteriorates, lead paint chips 
and dust concentrate in the surrounding soil. Renovating, remodeling, and performing routine 
home maintenance also will mobilize this lead if proper precautions are not taken. As with inte¬ 
rior paint, dry scraping, sanding, and blasting of exterior lead-based paint can mobilize large 
amounts of lead in a short time. Disturbing the old lead-based paint can increase lead concen¬ 
trations in soil, especially in the drip zone, or drip line, the area surrounding and extending 
out about 3 feet from the foundation of a building. (See Appendix D for information about an 
EMPACT program that addresses lead in residential soil). 
For additional information refer to an EPA fact sheet entitled, Identifying Lead Hazards in 
Residential Properties, which is included at the end of this chapter. 
1 While not primarily responsible for childhood lead poisoning, other sources of lead in the environment 
include emissions from industrial sources such as smelters, mining operations, and battery-recycling plants; 
soil contaminated from vehicular emissions (before leaded gasoline was banned in 1986); lead water pipes; 
lead-containing tableware and crystal glassware; some hobbies, such a stained glass-making; some folk 
remedies; and some types of jewelry and pewter-ware. 
2 Centers for Disease Control, Preventing Lead Poisoning in Young Children, 1991. 
1 □ 
Chapter 2 
