Nov. 12, 1999 (Atlanta) -- The incidence of lead poisoning has decreased dramatically over the last twenty years due to universal screening and education, according to a report in the November issue of Pediatrics. As more selective testing, instead of universal testing, becomes the norm, doctors say thorough patient histories will be needed to identify lead exposure.
"Over the past two decades, blood levels of lead have dropped substantially among children in the United States. Paint, dust, soil, and water remain the principal sources," says William Schaffner, MD, professor and chairman of the department of preventive medicine at Vanderbilt University in Nashville. "Now that these well-recognized sources are being eliminated, it's time to focus on more obscure sources of risk."
Some unusual sources of lead toxicity mentioned in the report include folk medicines, calcium supplements from bonemeal, contaminated flour and food coloring from the Middle East, candy packaged in jars from South America, as well as pottery and metal cookware from around the world. Ingestion of lead-based foreign objects including buttons and curtain weights also was reported. Schaffner tells WebMD, "once identified, all potential sources of exposure should be removed because lead poisoning is a chronic disorder that may have irreversible effects."
Chronic lead poisoning can lead to learning disabilities, mental retardation, kidney disease, and eventual death in children. Adults may additionally suffer from heart disease and stroke. In terms of signs and symptoms, Schaffner says, "children are likely to have a rapid onset of forceful vomiting and seizures. Adults are likely to report headache, abdominal pain, vomiting, and constipation over several weeks. Of course, lead levels can also be quite high with virtually no symptoms at all. In fact, we referenced two such cases."
In one case, a baby was found to have a high blood lead level (BLL) upon routine screening. Subsequent evaluation of the child's home environment identified no obvious sources, although discussion with parents revealed daily application of surma. Also known as kohl, surma is a fine black powder applied to the eyelids for cosmetic and medicinal purposes throughout Asia. The powder, found to be 25% lead, was discontinued and the child's BLL dropped by almost half within eight weeks.
In another case, a toddler was noted to have an elevated BLL during a routine exam. The health department was unable to identify any environmental sources, although, the mother suspected a metallic necklace. The necklace had been given as a gift 10 weeks earlier and the child had been frequently seen with beads in his mouth. After the child stopped wearing the necklace, his BLL decreased by half in only three weeks.
Because the necklace had been purchased at a large department store, the U.S. Consumer Product Safety Commission was notified. The CPSC did not take regulatory action since the product was not intended for toddler use. They did, however, ask the manufacturer to voluntarily remove unnecessary lead from such products. Ken Giles, a spokesperson for the CPSC, tells WebMD that "we welcome all such reports from consumers or health care agencies through our hotline" at (800) 638-2772.