To Your Health

A. Lead exposure is an ancient problem, and lead poisoning remains unnecessarily common among children. It is estimated to affect 4.4% of children, most dramatically those under 2 years of age, despite recent successful public health campaigns that have made the problem less common now than it was in 1974 when lead was removed from our gasoline supply. Some children continue to be exposed to levels of lead that will lower their IQs and increase behavior problems.

For more than a century, everyone has agreed that lead is toxic, but how much lead a child can tolerate without suffering damage of some kind is yet unknown. At various times in the past, the safe limit for blood lead has been set at 25 micrograms in 100 milliliters of blood, 20 mcg/dL, 10 mcg/dL, and most recently, 3 mcg/dL. These numbers were based in part on an inability to find children in America with lower lead levels, and since children were obviously still alive with as little as 3 mcg/dL blood lead levels, it was assumed that this was a safe amount. We now know that blood lead levels less than 3 mcg/dL for infants can still result in a permanent loss of IQ points, a shortened attention span, and increased expression of anti-social behaviors. We don't know how low is OK, and it will be years before research can answer this question, so for now the safest assumption is that any lead at all is detrimental to a child's development.

Avoidance of further lead exposure is the best remedy for lead intoxication. Be on the lookout for paint chips or dust that might contain lead. This is the most common source of lead for children. Don't store acidic foods, such as citrus juice, in handmade ceramic pottery or in leaded crystal. Find out if there are any lead water pipes in your house or if lead-containing solder has been used to repair water pipes or your water heater. Lead-contaminated spices, purchased in foreign countries and brought into the U.S., are occasionally found to be very high in lead. Do not allow small children to chew party and holiday paper decorations, candy-bar wrappers, and colorful sports trading cards, which may contain some lead. If you live close to any heavy industry, there may be lead in the air you and your child breathe.

Chelation therapy is generally thought to be the last resort in the treatment of lead poisoning. It involves the use of one or more chemicals that are designed to bind to lead and take it out of the body. There are several such chemicals with almost unpronounceable names that go by letters like EDTA, DMSA, BAL, dPEN, etc. Chelation therapy for children should be not considered unless a child's blood lead level reaches at least 25 mcg/dL (some practitioners say 45 mcg/dL). Chelation therapy removes not only lead but also much needed nutritional minerals such as copper, iron, zinc, and calcium.

Since lead interferes with formation of hemoglobin, supplements of copper, iron, zinc, calcium, and vitamin C, are likely to assist in restoration of normal blood chemistry and lessen the impact of lead toxicity. In addition, these nutrients tend to reduce the absorption and at the same time increase the excretion of lead.