By Jeff Ribordy, MD
Lead poisoning has been a public health issue for centuries. During the Roman Empire, it was caused by lead in aqueducts, water pipes, and drinking vessels. In fact, the word plumber comes from “plumbum,” the Latin word for lead. The medical term for lead poisoning is plumbism. During the Middle Ages, lead was used in alchemy. During the Renaissance, lead was used to make weapons of war, printing presses and other items.
By the 1900s the U.S. was the largest producer of lead in the world. It was used commonly in water pipes, paint, and as a gasoline additive. In 1904, however, it was recognized as dangerous to children. The first reports came from Dr. Gibson in Australia who linked lead paint to lead poisoning cases. In 1914 the first case of childhood lead poisoning was published in the United States. Through the 1920s and 1930s, more cases surfaced and the evidence mounted. But many physicians did not recognize the symptoms of lead poisoning. Not until after 1940 was a blood test developed to measure blood lead levels.
More and more physicians recognized the toxic nature of lead ingestion on children. Many other countries in the 1920s and 1930s passed legislation restricting or banning the use of lead paint indoors or in items such as cribs. However lead paint continued to be used in households in the U.S. until it was first banned in 1970. In 1978 the maximum allowable lead limit was lowered to 0.06 percent. (The previous industry standard was 1 percent even though many paints had levels up to 10 percent!)
Why is lead poisoning such an issue for children? Because of their growing and developing brains along with a tendency for kids to place everything in their mouths. No minimum safe lead level (other than zero) has ever been discovered. For decades the Centers for Disease Control used a BLL of 10 µg/dl as a “level of concern.” They recently reduced this to 5 µg/dl. Studies have shown brain damage (like loss of IQ points) even at levels less than 10. At higher levels, people can have abdominal pain. If exposure continues, seizures, coma and even death can result.
At low blood levels, children may have no symptoms. Their exposure can only be found by routine BLL screening. Current recommendations are to screen all children at one and two years of age. Any BLL greater than 5 should be investigated for a source in the home. This may be done by the local public health departments. Many older homes may still have lead paint. If paint is peeling or remodeling taking place, lead paint dust can be in the environment. Lead has also been found occasionally in toys, imported candy, and sometimes folk remedies from other countries (Greta or Azarcon in Latino cultures, Ghasard from India, or Ba-baw-san from China)
The take home message? Be sure to have your children’s blood level checked at ages 1 and 2.
— Dr. Jeff Ribordy is a Regional Medical Director of Partnership HealthPlan of California