(CN) – The D.C. Circuit upheld government standards preventing children from accumulating even low levels of lead in their blood, which causes a decrease in intelligence.
The Coalition of Battery Recyclers Association and Doe Run Resources Corp. challenged a 2008 rule setting the strictest-ever standards for lead released into the air. Airborne lead is absorbed into the bloodstream, affecting the developing brains of children. Children with even small amounts of lead in their blood can appear inattentive, hyperactive or irritable, and higher blood lead levels can slow or delay a child’s learning and growth.
Standards in 1978 aimed to prevent children from exceeding blood lead levels of 30 micrograms per deciliter. But after studies in the early part of this century, the EPA determined in 2004 that “there is now no recognized safe level of [lead] in children’s blood.”
Studies indicated a link between air lead level and loss of IQ in children, including a distressing non-linear relationship whereby low blood lead levels had a much greater effect on IQ than higher levels.
IQs in children with blood lead levels of 10 mcg/dl were seven points lower than in children with less than 1 mcg/dl of lead in their blood, a 2003 New England Journal of Medicine study found.
The EPA developed its new standards based on an air-to-blood ratio equivalent to allowing the loss of two IQ points, which is already “highly significant from a public health perspective,” according to a scientific advisory committee.
The federal appeals court in Washington, D.C., upheld this standard, saying the Clean Air Act is designed to protect sensitive subpopulations such as children.
“[A] small change in IQ at the level of an individual is a substantial change at the level of a population,” Judge Judith Rogers wrote for the three-judge panel.
The agency adequately justified which studies it used to base its analysis, using a rolling three-month average to calculate the levels, the court said.
Blood lead level in U.S. children has declined by 80 percent since the late 1970s, while evidence shows that IQ has increased three points per decade during this time. According to the Centers for Disease Control, about 5 percent of young American children have blood lead levels above 10 mcg/dl. The average blood lead level for U.S. children is about 1.7 mcg/dl.