What causes lead poisoning?
- Well, obviously, lead. While lead is found in the environment (in dirt), it is the industrial use of lead that causes exposures significant enough to raise the blood lead level of children.
What products contain lead?
- Leaded gasoline fumes (leaded gasolines were gradually removed from the United States market beginning in the 1970's)
- Peeling paint chips and dust (especially in houses built in the 1970's or earlier)
- Lead objects that are eaten (i.e., fishing weights)
- Shotgun pellets or a bullet that remains in the body for a prolonged period of time
- Improperly lead-glazed ceramic cookware
- Burning lead-based painted objects or batteries and inhaling the fumes
- Food stored in leaded glass containers
- Lead water pipes
How does lead "get into" children?
The gastrointestinal tract
- A child's hand touches a dusty paint surface and then the mouth
- A child drinks water that has traveled through lead pipes
- A child eats a meal that was stored or served in lead-glazed ceramic ware
- Leaded gasoline fumes
- Sanded paint that is inhaled
How does lead harm children?
- Lead serves no good purpose in human metabolism.
- Once in the bloodstream, lead binds to proteins on red blood cells. The production and function of heme (the oxygen-carrying protein) is disrupted.
- Lead competes with calcium that normally binds to proteins and assists with chemical messaging in nerves.
- Lead may affect normal brain development.
What are the symptoms of lead poisoning?
Symptoms are generally worse as the blood lead level rises.
Mildly elevated blood lead levels
- Hyperactivity or decreased activity
- Behavior changes
- Lower intelligence (IQ)
- Abdominal pain
High blood lead levels
- Ataxia ("acting drunk")
How is lead poisoning diagnosed?
The diagnosis may be suspected when routine screening surveys reveal risk factors.
A blood lead level can confirm the diagnosis. The ideal blood lead level is zero, although levels less than 10 micrograms/dL are considered "normal." Higher blood levels usually mean the child is at a higher risk of severe effects. A "finger-stick" blood sample (capillary sample) must be confirmed by a venous sample if it is elevated to rule out contamination of the sample.
- 0-9 mcg/dL "normal"
- 10-19 mcg/dL investigate possible sources of exposure and retest until the value lowers
- 20-69 mcg/dL remove the source of lead exposure, monitor blood levels closely, consider using a medicine to help eliminate lead from the body (a chelating agent)
- 70 or above immediate hospitalization
In children, lead deposits in the long bones (arms and legs) may be evident on X-rays. Lead objects or paint chips can occasionally be seen on x-rays.
How is lead poisoning treated?
- Remove the lead source (if it can be determined)
- Check the blood lead level of other children in the family
- Medicines that bind to lead and allow it to be removed in the urine include: succimer or DSMA, penicillamine, dimercaprol, and edetate calcium disodium (chelation agents). DMSA and penicillamine can be given orally, while dimercaprol, and edetate calcium disodium must be given as an injection or intravenously.
- Other important body metals may need to be replaced after chelation therapy (i.e., zinc, calcium, iron, copper)
- Increased fluid intake will help excretion of lead in the urine
- Control of seizures (if necessary for those with extremely high lead levels)
Last Updated (Sunday, 29 August 2010 12:01)