Lead poisoning is a common preventable disease in Canada and the U.S. Most commonly, lead poisoning is caused by repeated
exposure to small amounts of lead. Once lead is in the body it does not leave on its own. If enough lead accumulates in the
body it causes lead poisoning. There may not be any obvious symptoms, so parents of children with mild lead poisoning may
not know to seek medical help. Poisoning by low levels of lead can cause silent brain damage. The brain is most sensitive
to lead exposure during the first 6 years of life. The brain damage results in such problems as lowered IQ scores (an average
of 7 IQ points lost), decreased attention span, decreased hearing, speech delays, and other developmental delays. Though uncommon,
exposure to large amounts of lead causes severe lead poisoning and major symptoms. The symptoms of severe lead poisoning include
abdominal pains, headaches, vomiting, confusion, muscle weakness, seizures, hair loss, and anemia.
Sources of lead exposure
The most common source of lead exposure for children is lead-based paint. Lead was finally banned from house paint in 1978.
Three-quarters of all houses built before 1960 contain lead-based paint. When paint chips or peels, young children can pick
up these particles and chew them. More commonly, children swallow dust and soil contaminated with lead paint. Home remodeling
and sanding put a great deal of lead powder into dust and soil. Because toddlers commonly put their hands in their mouths,
suck their thumbs, and explore their environment by tasting things, they are at greater risk for lead poisoning. Other sources
of lead are air, water, and food. The amount of lead present in the air from automobile exhaust has been markedly reduced
by the almost complete phasing out of leaded gasoline in the U.S. Lead is found in low levels in some drinking water because
lead-based solder on old water pipes may add lead to water. (Lead-based solder was not banned for use with water pipes until
1986.) Lead is also sometimes found in fruit juice, food stored in lead-glazed pottery, low-quality toys, metal trinkets,
and crayons.
Prevention of lead poisoning
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Make sure your child is not exposed to peeling paint. Pay special attention to windowsills.
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To remove lead dust:
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Rinse your child's hands and face before she eats.
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Rinse toys and pacifiers frequently.
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If your child sucks his thumb or fingers, rinse his hands frequently.
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Wet-mop your hard surface floors.
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Close off rooms that are being remodeled.
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If you have leaded paint on the outside of your house, keep lead dust from being tracked into your house. Have a washable
mat at each door entry so everyone who enters wipes their feet. If the soil around your house is definitely contaminated with
lead, have a rule that people take off their shoes before coming into your house.
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If the soil around your home is contaminated with lead, replace it or plant bushes next to the walls so that children cannot
play there.
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If you need water for cooking or for preparing formula, use only water from the cold water tap. If the water hasn't been used
for several hours, let the water run for 2 minutes before you use it. (Lead dissolves more in warm water or standing water.)
If you are concerned, have your water tested for lead.
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Do not store food or drink in pottery that may not have been fired correctly.
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Make sure your child's
diet contains enough iron and
calcium. Both of these minerals make it harder for the body to absorb
lead.
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Make sure that your child isn't being exposed to lead through contact with adults who have occupations or hobbies that involve
lead.
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Make sure your child's toys and crayons are made by a reputable manufacturer.
Screening for lead poisoning
Lead poisoning is diagnosed by a blood test. In 1997 the Centers for Disease Control and Prevention, Atlanta, suggested the
following situations as reasons for testing a child for lead poisoning:
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The child lives in or regularly visits a house or structure with peeling or chipped paint that was built before 1950, including
day care centers, preschools, or homes of baby sitters and relatives.
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The child lives in or regularly visits a home that is being renovated and was built before 1978.
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The child has a brother, sister, housemate, or playmate who is being followed or treated for lead poisoning.
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The child lives with an adult whose job or hobby involves exposure to lead. Examples of such jobs or hobbies include furniture
refinishing, making stained glass, making pottery, using indoor firing ranges, and working in industries such as storage batteries,
automotive repair, and bridge, tunnel, and elevated highway construction.
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The child lives near an active smelter, battery recycling plant, mine tailing pile, or other industry likely to release lead.
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The child receives medical treatment for removal of a foreign body from the ear, nose, or stomach.
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The child has the habit of swallowing nonfood substances (pica).
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The child is less than 6 years old and has an unexplained
developmental delay, hearing defect, irritability, severe attention
deficit, violent tantrums, or unexplained anemia.
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The child lives in a neighborhood at high risk for lead poisoning (often identified by zip code).
Children who remain at high risk for lead exposure should be tested for lead at least every year until their sixth birthday.
The levels of lead when a child is 12 months old and 24 months old are especially important.
Treatment of lead poisoning
Children with high levels of lead in their blood or symptoms of lead poisoning need to start taking a medicine (called a chelating
agent) that binds with the lead and carries it out of the body. All children with any elevated levels of lead need to be protected
from re-exposure to the lead until it is removed. A public health agency or housing agency should carefully inspect the child's
home environment for lead hazards. The family should take all of the precautions for preventing lead exposure.
| Last Reviewed | Reviewed by |
| June 21, 2004 | Andrew James, MBChB, FRACP, FRCPC |