LEAD-CONTAMINATED DUST
Most U.S. children with lead poisoning have been exposed to lead-contaminated dust from lead-based paint found in an older home. Lead-contaminated dust often enters a child's body because it gets on a child's hands and toys that during normal activities are placed in their mouths. The tiny specks of lead in dust are often impossible to detect visually and a very small amount can be dangerous to children. Lead-contaminated dust can be cleaned by following lead-safe cleaning tips. Federal standards identifying hazardous levels of lead-contaminated dust are 40 micrograms per square foot for floors; 250 for window-sills. A separate standard for window troughs of 800 micrograms per square foot is used only after work that disturbs lead-based paint. This standard is not used to identify lead hazards but solely to document that a thorough cleaning was completed to remove dust with lead. For further information on federal standards relating to lead-contaminated dust, contact the U.S. Deparment of Housing and Urban Development (HUD) or the National Center for Healthy Housing.

EXPOSURE FROM LEAD-BASED PAINT
Lead-based paint is most frequently found in housing constructed before 1950. The federal government defines lead-based paint as paint containing greater than or equal to 1 milligram of lead per square foot (mg/ft2) or 5% by weight. More information is available by contacting the Department of Housing and Urban Development (HUD). Lead-based paint that is in good condition is generally not a health hazard. However, when such paint is peeling, flaking, chipping or otherwise deteriorating it can create lead-contaminated dust and paint chips that pose a potential health risk, especially to young children. Lead-based paint is also a potential hazard if it is disturbed during remodeling or repainting activities that create lead-contaminated dust. Simple precautions can be taken to control, contain and clean up lead dust during home improvement projects. Eating lead-based paint chips can also poison children, but this event is relatively rare.

Housing age is an important predictor of potential lead hazards. Paint manufactured before 1950 has more lead than paint made after the late 1950's. Exposure to lead-contaminated dust from lead-based paint found in older homes is the primary way in which most young children in the United States become lead-poisoned.

Poor housing maintenance is a risk factor for potential lead hazards. Most lead poisoned children come into contact with lead-contaminated dust that comes from deteriorating paint in poorly maintained older housing. A smaller number of cases of lead poisoning is caused by repainting and remodeling projects. Such projects tend to disrupt old painted surfaces and spread lead-contaminated dust that is hazardous when it is not properly controlled, contained, and cleaned. Simple lead-safety precautions can control lead-contaminated dust during home improvement projects.

The Centers for Medicare and Medicaid, the federal agency that oversees the Medicaid program, requires blood lead screening for all children enrolled in Medicaid at 12 and 24 months, and for any child 36-72 months of age who has no record of prior screening.

OTHER ROUTES OF EXPOSURE
Although more children are poisoned by exposure to lead dust from lead-based paint in older homes than by any other source, lead can also be found in soil, water, air and food. Soil in the vicinity of the home may be contaminated from flaking exterior lead-based paint or previous deposits of leaded gasoline. Children then play in that dirt and directly ingest it, or track it into the home on the bottoms of their shoes. Lead may enter drinking water from the solder used to join metal pipes. Those who work in construction, demolition, painting, radiator repair shops, lead factories, with batteries, or enjoy a hobby that involves lead are often exposed to lead. Lead particles may be carried home on clothing, shoes, or hair, putting family members in jeopardy. Other less common sources include food and drink stored in leaded crystal, lead soldered cans, or lead glazed ceramicware, hobbies that involve lead, and home remedies and cosmetics that are popular in some cultures.