Exposure to lead even at low levels resulted in poor academic performance among Connecticut schoolchildren and may be a factor in the state’s large achievement gap among black children, a new Duke University study shows.
Lead exposure during early childhood had a negative effect on statewide fourth-grade achievement test scores even when exposure was at levels below a minimum federal standard used for defining lead poisoning, according to the study.
Although the prevalence of lead poisoning has declined steadily among young children in Connecticut over the past decade, officials said the study indicates that childhood lead exposure remains a critical health and educational concern.
“There is no safe level of lead exposure…Lead is a real issue in our state, and it’s completely preventable,” said Francesca Provenzano of the state Department of Public Health, who was among officials presenting the study to the State Board of Education this week.
“All of these children who have a history of lead poisoning end up in the school system and often need special services and more attention in the classroom,” she said.
The federally-funded study by Duke’s Children’s Environmental Health Initiative is patterned after a project that produced similar results among North Carolina schoolchildren.
The study examined Connecticut Mastery Test reading and mathematics scores for about 35,000 white and black fourth-graders who had been screened as young children for lead exposure. The analysis was designed to zero in on the effects of lead by adjusting for other factors commonly associated with educational achievement, such as race, sex, income level and special education status.
Even at levels markedly below the minimum “blood lead action level” established by the federal Centers for Disease Control, the study produced a consistent pattern of decreased performance in reading and math: The greater the exposure, the lower the scores.
Various other research studies have linked childhood lead exposure low IQ scores, cognitive difficulty, behavioral problems and attention deficits.
Researchers said the problems in school performance are likely to be more acute among black children because they are more likely than white children to be exposed to lead–a disparity found in both the North Carolina and Connecticut studies.
Across the nation, minority children, on average, lag significantly behind white children on state tests. In Connecticut, that performance gap that is among the largest in the nation. Although many factors influence school performance, the research study concluded “that exposure to lead may account for part of the achievement gap among Connecticut schoolchildren.”
Lead is often found in the paint in older homes, typically around old windows and doors, and can also be found in soil and dust.
“The incidence is higher in urban centers based on exposure, based on older housing,” said Charlene Russell-Tucker, associate commissioner in the State Department of Education’s Division of Family and Student Support Services.
“If a child is exhibiting developmental delays, having speech issues, any learning disabilities – you look at [all] the things that could be contributing to that,” she said.
State figures show a steady decline in the proportion of children under the age of six who have lead poisoning, from about 6 percent of those tested in 1995 to about 1 percent in 2009.
“It’s encouraging news,” said Russell-Tucker. “However, we know there are kids already in the system [with lead exposure], so if we could eliminate this problem, we wouldn’t have to be concerned about it.”
The state health and education departments already run a variety of lead prevention and awareness programs. Officials said the latest study will be used to bolster efforts to raise awareness and develop guidelines to address the problem.
Duke researchers are expected to conduct a second phase of the Connecticut study using results of the 2010 Mastery Test. The first phase included test scores from 2008 and 2009. The study was commissioned by the Connecticut Children’s Medical Center and the state education and health departments.