The Risks of Lead Exposure

Risks of lead exposure in children are well known and frequently publicized. For example, the news was recently full of stories of imported toys from China which were decorated with lead-containing paint. Children are commonly exposed to lead by eating lead-containing substances such as paint from older homes and buildings or dust and soil contaminated by lead-containing gasoline. Too much lead in children’s bodies can lead to irreversible problems in behavior and learning problems, decreased intelligence, slowed or stunted growth and hearing problems. Children are more susceptible than adults because lead can accumulate in their growing nervous systems.

Although less publicized, adults also can suffer from lead poisoning. It is very difficult to recognize because the toxic levels usually build up slowly and the signs and symptoms of lead poisoning are nonspecific – that is, they can suggest many diseases other than the relatively uncommon diagnosis of lead poisoning. With growing public health awareness of the risks of lead poisoning, many risks for lead exposure have been reduced and there is a declining trend in elevated blood levels. In 2002, the Centers for Disease Control estimated that 10.1 adults per 100,000 had elevated blood levels. Another source estimated that 700,000 adult Americans had high lead blood levels.

While most children are exposed to lead via a gastrointestinal route – that is, by eating paint, dust or dirt – adults are mainly exposed via a respiratory route – that is, by inhaling paint dust scraped or sanded from various surfaces or via various smelting or burning processes. Many people are exposed in work settings, such as manufacturing or use of batteries, pigments, solder, munitions, paint, car radiators, ceramic ware with lead glazes and tin cans. Lead smelting and refinement and construction trades are also significant routes for exposure. Hobbies such as stained glassmaking, building lead-based models, loading lead ammunition and making ceramics can also increase lead exposure.

Some cans from outside of the U.S. are made with lead and eating food or juice from them can be risky. Some alternative medicines and supplements such as ayurvedic medications from India and litargio – a lead-based powder used in some Hispanic communities for an antiperspirant/deodorant and a folk remedy – can also produce lead poisoning. Many older homes have pipes connected with lead solder and drinking water from these pipes can lead to high lead levels. Finally, drinking ‘moonshine’ has been linked with high blood lead levels.

Adults with lead poisoning typically have abdominal pain, constipation, irritability, anemia and difficulty concentrating. They may also have pain, numbness, or tingling of the arms or legs, muscle weakness, headaches, cataracts and reduced sperm count. Long-term exposure to even relatively low levels of lead can increase risk for high blood pressure and kidney disease. Lead poisoning can be diagnosed by a blood test. A 24-hour collection of urine can provide additional information but is not usually needed unless the blood lead level is quite high. Measuring lead in urine or hair is not very reliable or accurate.

The best way to treat lead poisoning is simply removal from lead exposure. For workers with occupational exposure, this may mean transferring to another area or leaving the workplace altogether. Often, steps can be taken to reduce dust or use personal protection devices. For household exposures, if you have lead pipes or lead solder in your home, let cold water run 30 to 60 seconds before drinking it and consider switching to bottled water. Avoid use of certain imported canned foods. Avoid pewter pitchers and dinnerware. Don’t store wine, spirits, or vinegar-based salad dressings in lead crystal decanters for long periods of time, as lead can leach out into the liquid.

If lead levels and symptoms are pronounced, chelation therapy may be necessary. This is a therapy in which medications are given which bind to lead in the bloodstream and convert the lead into forms that can more easily be excreted. This is a fairly drastic treatment and should only be given under the close supervision of a toxicologist, a physician experienced in the treatment of illnesses caused by drugs and other poisons.

Dr. McMahon, a graduate of Yale University and the University of Pittsburgh School of Medicine, is board certified in Internal Medicine. She is a member of the American College of Physicians and the Allegheny County and Pennsylvania Medical Societies. She is in solo practice in the North Hills of Pittsburgh.