Lead Exposure and Education Results
Lead poisoning has serious implications for children’s health, education, and ability to thrive. There are significant harmful effects on young children even with low blood lead levels, including decreased IQ and academic achievement, attention deficit disorder, delayed puberty, reduced growth, decreased hearing, and damage to the nervous system.
There is no safe level of lead exposure for children; lead affects intelligence even at very low levels. As a child’s blood lead level (BLL) increases from 1 to 10 µg/dL, experts estimate a loss of anywhere from 3.9 to 7.4 IQ points; and from 10 to 30 µg/dL, the decrement is 2.5 to 3.0 IQ points. Low-level chronic exposure may have an even greater effect on IQ than a single instance of very high BLL. Several recent studies have explored the specific effects of lead on educational outcomes. These studies show a strong relationship between slightly elevated blood lead levels in young children and decreased scores on end-of-grade tests in elementary school. While similar educational effects were documented for higher blood lead levels decades ago, recent studies confirm that the connection between blood lead and poor educational outcomes remains true for blood lead levels as low as 3-4 µg/dL.
Research indicates that a five-point negative shift in IQ at the population level would increase the number of children with an “extremely low” IQ by 57 percent, substantially increasing the cost of special education programs. Considering the costs to the special education system alone, one study conservatively estimated that it costs $38,000 over three years to educate a child with lead poisoning.
Low-level exposure to lead has also been linked to factors other than IQ that can further impact educational outcomes. EBLLs are associated with Attention Deficit Hyperactivity Disorder (ADHD) and antisocial behavior, which in turn increase the likelihood of conduct disorder.
The impact of lead exposure is not limited to individual children and their families, but extends to society as a whole:
- Ultimately, lead exposure costs the nation more than $50 billion in lost lifetime productivity.
- Recently released U.S. test scores show that U.S. students’ scores still lag far behind other developed countries on reading tests. As the U.S. attempts to keep its competitive edge, we cannot afford to allow an environmental toxin to interfere with the potential of our future generations. Children who ingested even small amounts of lead performed poorly later on school tests compared with students who were never exposed to the substance, according to a Duke University study of Connecticut students.
- Loss of IQ points from elevated blood lead levels is estimated to result in a total lifetime earnings loss of $165-233 billion.
- The average annual cost of special education was $12,833 (in 1998 USD). Therefore, the average cost of special education for three years will be about $38,000 per child.