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Environmental Services

Learn About Lead and Its Dangers


What is lead?

Lead (chemical symbol Pb) is a heavy, toxic, poisonous chemical element. It is a soft, malleable metal that is bluish-gray in color.

History of lead knowledge and use:

  • Negative effects of lead were recognized by Ben Franklin in 1786; however, lead use and occupational exposures accelerated during the 1800s.
  • The first time a case of lead paint poisoning was diagnosed was in Australia, in 1895.
  • Residential lead-based paint was sold in the United States until 1978. More than 38 million U.S. homes still contain lead-based paint.
  • Why was lead added to paint? Better pigmentation, durability and corrosion resistance.

Lead poisoning

Childhood lead poisoning is an environmental health problem that causes adverse effects on children's development and later in adulthood. On average in San Diego County, there are approximately 114 cases per year (56 cases in the City) of lead poisoning in children with blood lead levels greater than or equal to the amount recognized by the Federal government as a concern (10 micrograms of lead per deciliter of blood).

Photo of Cracked PaintPhoto of CandyPhoto of PotteryHow are we exposed to lead-based paint?

  • The biggest source of lead exposure is from deteriorating lead-based paint on homes built before 1978.
  • Twenty-eight percent of lead poisoned people in San Diego live in homes in which lead-based paint or contaminated dust is a possible source.
  • Normal wear and tear produces lead dust, the most common source of lead poisoning.
  • Deteriorating paint produces dust and flakes.
  • Disturbing intact lead-based paint during remodeling, renovation and maintenance can create a lead hazard.
  • Other sources of lead can sometimes include: pottery used for food, home remedies, candy, water, toys, soil, toy jewelry, decorative goods, hobbies and occupational exposures.

How does lead poison us?

  • Swallowing lead dust or flakes. This is especially true for young children who crawl on the floor and put their hands and toys in their mouths.
  • Breathing in lead dust during maintenance or renovation activities that disturb old paint.
  • Lead can harm unborn children when lead from the mother’s blood passes to her unborn child.

How do we know if we have been exposed to lead?

The only sure way to know if you have been exposed to lead is to have a blood-lead test. Doctors do not normally perform this test. You must ask for it.

Children should be tested at 1 and 2 years of age, and afterwards as recommended by the child’s physician.

Photo of Child Being Examined by Doctor

Usually there are NO obvious symptoms, but symptoms of lead poisoning frequently include:

  • Fatigue
  • Irritability
  • Headache
  • Constipation
  • Stomach ache
  • Cramps
  • Vomiting
  • Weight loss
  • Behavior problems

What are the health effects of lead in our bodies?

  • Loss of IQ
  • Learning difficulties
  • Behavior problems
  • Brain and nerve damage
  • Stillbirth and miscarriage
  • Premature birth
  • Low birth weight

The Federal government states that the current level of concern regarding how much lead is in a child's blood is 10 µg/dL (micrograms of lead per deciliter of blood). Research has shown however, that a child's IQ can be negatively affected at lead levels lower than 10 µg/dL.