December 2007
The resurgence of lead
The appearance of lead in toys, jewelry, and even baby bibs has come after years of progress in reducing lead hazards across
the country. Some of the reasons involve the malleability of the metal for fashioning products, the growth of imported goods,
and even recycling.
For example, lead has appeared in millions of pieces of inexpensive jewelry marketed to children and teenagers. Many jewelry items with lead content of 90 percent or more have come from China and appear to be made from recycled lead battery waste and electronics boards, according to recent studies led by Jeffrey Weidenhamer, a chemistry professor at Ashland University in Ohio. "Recycling is great, but not when you're turning lead waste into children's jewelry," he says.
Lead is also found as a stabilizer in plastics. But there are safer alternatives: Tin, for example, is a less toxic ingredient.
The federal Centers for Disease Control and Prevention reported in 2005 that in some areas of the country, more than a third of children identified as having elevated blood lead levels have been exposed to items made of or decorated with lead. From paint to toys, "every little bit counts because once lead is in the body, it's very difficult to remove it," says Mary Jean Brown, chief of the CDC's lead poisoning prevention branch.
Americans' exposure to lead over much of the past century was driven by two products in particular: paint and gasoline. By the late 1980s, those two industries had each used about 6 million tons of lead in the U.S., the toxic residue of which still lingers. More than a third of the nation's housing stock still contains some lead paint, and one out of four homes with children age 6 or younger has significant lead hazards in paint, dust, and soil, according to estimates.
Since the federal government banned lead in gasoline and house paint beginning in the 1970s, the average blood lead level in children under age 6 has dropped about 90 percent. Even so, based on the latest data available from the National Center for Health Statistics, 460,000 children under age 5, or 2.4 percent, have elevated levels. High levels are defined by the CDC as 10 micrograms or more per deciliter of blood. That's down from 60 micrograms in the 1960s, when health officials were focused on preventing potentially fatal lead poisoning, which can occur at higher levels.
Now 10 micrograms is the level that generally triggers some form of intervention by doctors or public health officials. The Environmental Protection Agency recommends that all children have blood lead level tests at age 1 and again at age 2.
In an adult, blood lead levels typically reflect only a small portion of total lead exposure. So someone with a relatively low level of lead in the blood might have a bone lead level that is proportionally 1,000 times greater, reflecting lifetime exposure. The body treats the metal like calcium, so when demand for that mineral increases, lead may be absorbed back into the bloodstream.
Results of a 2006 study published in Circulation: Journal of the American Heart Association indicate that an increase in an adult's blood lead level from about 1.9 micrograms per deciliter to 3.7 micrograms per deciliter increases the risk of dying of a stroke by about 2.5 times. "People know that lead exposure is dangerous for children, but I don't think they fully appreciate that it is extremely hazardous for adults," says Ellen Silbergeld, professor of environmental health sciences at Johns Hopkins Bloomberg School of Public Health and co-author of the study.
Critics say federal watchdogs have not been doing their job. The CPSC has "been neutered to the point of uselessness," says Ann Brown, the agency's chairman from 1994 to 2001. "It just makes me shiver to think this is the agency that is supposed to be protecting our kids," she says. Nancy Nord, acting chairman of the CPSC, defended her agency in September before a congressional subcommittee, saying, "The CPSC has been and continues to be ever vigilant and assertive in this ongoing war against children's exposure to lead in products under our jurisdiction."
Even the CDC advisory committee on lead poisoning prevention may have been subjected to political pressure, according to a report issued by U.S. Rep. Edward Markey (D-Mass.) in the fall of 2002. The report concluded that committee nominations of scientists renowned for their work on lead poisoning were being rejected in favor of people tied to the lead industry.
At that time, the agency was considering whether the definition of an "elevated" blood lead level should be lower than 10 micrograms per deciliter, the standard set in 1991. Recent studies suggest that the greatest incremental damage to children's brains appears to occur below the prevailing 10 micrograms standard, with evidence of harm at levels as low as 2.5 micrograms per deciliter.
Two-thirds of the typical nine-point decline in IQ experienced by children with blood lead levels between 10 and 30 micrograms might actually occur at levels below 10 micrograms, according to a July 2005 study by an international group of lead researchers. The Johnsons' pediatrician, aware of such research, recommended action when Coen's lead blood level came in at 9 micrograms per deciliter and Nora's came in at 7. "A lot of parents are simply told their kids' tests are 'normal' if they're below 10," says Christine Johnson.
For example, lead has appeared in millions of pieces of inexpensive jewelry marketed to children and teenagers. Many jewelry items with lead content of 90 percent or more have come from China and appear to be made from recycled lead battery waste and electronics boards, according to recent studies led by Jeffrey Weidenhamer, a chemistry professor at Ashland University in Ohio. "Recycling is great, but not when you're turning lead waste into children's jewelry," he says.
Lead is also found as a stabilizer in plastics. But there are safer alternatives: Tin, for example, is a less toxic ingredient.
The federal Centers for Disease Control and Prevention reported in 2005 that in some areas of the country, more than a third of children identified as having elevated blood lead levels have been exposed to items made of or decorated with lead. From paint to toys, "every little bit counts because once lead is in the body, it's very difficult to remove it," says Mary Jean Brown, chief of the CDC's lead poisoning prevention branch.
Americans' exposure to lead over much of the past century was driven by two products in particular: paint and gasoline. By the late 1980s, those two industries had each used about 6 million tons of lead in the U.S., the toxic residue of which still lingers. More than a third of the nation's housing stock still contains some lead paint, and one out of four homes with children age 6 or younger has significant lead hazards in paint, dust, and soil, according to estimates.
Since the federal government banned lead in gasoline and house paint beginning in the 1970s, the average blood lead level in children under age 6 has dropped about 90 percent. Even so, based on the latest data available from the National Center for Health Statistics, 460,000 children under age 5, or 2.4 percent, have elevated levels. High levels are defined by the CDC as 10 micrograms or more per deciliter of blood. That's down from 60 micrograms in the 1960s, when health officials were focused on preventing potentially fatal lead poisoning, which can occur at higher levels.
Now 10 micrograms is the level that generally triggers some form of intervention by doctors or public health officials. The Environmental Protection Agency recommends that all children have blood lead level tests at age 1 and again at age 2.
In an adult, blood lead levels typically reflect only a small portion of total lead exposure. So someone with a relatively low level of lead in the blood might have a bone lead level that is proportionally 1,000 times greater, reflecting lifetime exposure. The body treats the metal like calcium, so when demand for that mineral increases, lead may be absorbed back into the bloodstream.
Results of a 2006 study published in Circulation: Journal of the American Heart Association indicate that an increase in an adult's blood lead level from about 1.9 micrograms per deciliter to 3.7 micrograms per deciliter increases the risk of dying of a stroke by about 2.5 times. "People know that lead exposure is dangerous for children, but I don't think they fully appreciate that it is extremely hazardous for adults," says Ellen Silbergeld, professor of environmental health sciences at Johns Hopkins Bloomberg School of Public Health and co-author of the study.
Critics say federal watchdogs have not been doing their job. The CPSC has "been neutered to the point of uselessness," says Ann Brown, the agency's chairman from 1994 to 2001. "It just makes me shiver to think this is the agency that is supposed to be protecting our kids," she says. Nancy Nord, acting chairman of the CPSC, defended her agency in September before a congressional subcommittee, saying, "The CPSC has been and continues to be ever vigilant and assertive in this ongoing war against children's exposure to lead in products under our jurisdiction."
Even the CDC advisory committee on lead poisoning prevention may have been subjected to political pressure, according to a report issued by U.S. Rep. Edward Markey (D-Mass.) in the fall of 2002. The report concluded that committee nominations of scientists renowned for their work on lead poisoning were being rejected in favor of people tied to the lead industry.
At that time, the agency was considering whether the definition of an "elevated" blood lead level should be lower than 10 micrograms per deciliter, the standard set in 1991. Recent studies suggest that the greatest incremental damage to children's brains appears to occur below the prevailing 10 micrograms standard, with evidence of harm at levels as low as 2.5 micrograms per deciliter.
Two-thirds of the typical nine-point decline in IQ experienced by children with blood lead levels between 10 and 30 micrograms might actually occur at levels below 10 micrograms, according to a July 2005 study by an international group of lead researchers. The Johnsons' pediatrician, aware of such research, recommended action when Coen's lead blood level came in at 9 micrograms per deciliter and Nora's came in at 7. "A lot of parents are simply told their kids' tests are 'normal' if they're below 10," says Christine Johnson.
