Tuesday, October 21, 2014

Definition

In lead poisoning, ingested or inhaled lead enters the bloodstream. It inhibits the production of hemoglobin - which is needed by red cells to carry oxygen - and locks onto and inactivates essential enzymes in the brain and nervous system.

Description

Lead is highly toxic, even in minute quantities. Some historians suggest that widespread lead poisoning contributed to the decline of ancient Rome, where the metal was used for tableware, weapons, cosmetics, wine-making, and water pipes in aqueducts.

Causes

While adults, especially those in certain occupations and industries, are vulnerable to lead poisoning, small children are at the greatest risk. Children are highly sensitive because their nervous systems and brains are still developing.

Although rates of lead poisoning are higher among low-income, inner-city children, no socioeconomic group, geographic area, or racial or ethnic population is spared.

Incidence

Children living in older homes with peeling, lead-based paint present the highest incidence of lead poisoning. Research has shown that dust from deteriorating paint poses a pervasive threat as it settles on window-sills, furniture, carpets, clothes, and toys, eventually making its way into a child's mouth. Some cases also result from toddlers eating the sweet-tasting paint chips and flakes.

Warning On Lead Crystal

One study found that wine and acidic juices can draw the lead from lead crystal glassware. Thus the Food and Drug Administration recommends caution in the use of lead crystal glassware.

Because of lead's hazard to the fetus and to children's developing nervous systems, this FDA caution is especially directed to children, and to women who are pregnant or are considering pregnancy.

Symptoms

Symptoms of lead poisoning can include abdominal pain, muscular weakness and fatigue, constipation, and headache. Severe exposure can cause nervous system disorders, high blood pressure, and even death.

Diagnosis

A medical history including a lead exposure risk-assessment, physical exam, and blood tests will be performed.

The current definition of lead toxicity is 10 micrograms, or greater, per deciliter of blood. Studies have shown that blood levels as low as 10-15 micrograms per deciliter can be associated with diminished intelligence, impaired behavioral development, impaired hearing, and inhibited growth.

The optimal frequency of screening for lead exposure in children is not established.

Treatment

Lead poisoning can be treated if treatment begins before too much damage has occurred.

Lead is removed through a process called chelation, using drugs to bind to the metal in the bloodstream, flushing it out in the urine. Medications include calcium-disodium (EDTA), which is usually administered intravenously over several days in a hospital, and succimer (DMSA), which does not require hospitalization. Succimer (Chemet) has become the preferred chelating agent for less severe cases because it can be given by mouth.

Questions

Why is lead dangerous?

Does the drinking water contain high levels of lead?

Should the family be screened for lead?

Can drugs be used to remove lead from the bloodstream?

Prevention

Eliminating opportunities for lead exposure at home or at work is very important. Contact your local public health department's environmental health section if you have questions about the lead exposure risk in your home, building, or work environment.