Children who tested with elevated blood-lead levels at age 11 became adults with lower cognitive function and obtained jobs lower on the socioeconomic ladder, according to a study that suggests childhood lead exposure can have far greater consequences than previously confirmed.
Researchers at Duke University followed a group of kids who had high levels of lead in their blood in the 70s.
Thirty years later, the kids had lower IQs, lost IQ points over time, and became downwardly mobile, losing socioeconomic status from their parents, according to a study published Tuesday in the Journal of American Medical Association.
"What our study shows is that lead exposures in childhood are going to carry long-term consequences for both intellectual ability and the kinds of jobs that people end up getting," said the study's lead author, Aaron Reuben, a graduate student in clinical psychology at Duke University.
Public health officials have said for years that there is no safe level of lead in a child's blood. Lead is a neurotoxin. Exposure can seriously affect the IQ and cause major cognitive and behavioral problems in children.
What the medical community and public learned Tuesday is that those health impacts continue far into adulthood and can change the entire course of a child's life, according to the author's study.
It's something Grant Hill area mom Silvia Leon says she's been concerned about for a long time.
"Lead in your system, it's a poison," Leon said. "It causes irreversible damage."
In the 92102 zip code, which includes Sherman Heights, Grant Hill, Mount Hope and parts of Chollas Creek, the rate of children with high levels of lead in their blood is nearly as high as the rate found in children across the city of Flint, during its recent water crisis.
In Flint, that rate was 5 percent. In Grant Hill, the rate is 4.09 percent - less than a percentage point of a difference.
That's according to the most recent data available provided to NBC7 Tuesday by the California Department of Public Health.
NBC7 mapped out the top 23 zip codes in San Diego County where the highest rates of lead exposure were found in children. Find the map below.
Currently, less than seven percent of all total children in San Diego County are screened for lead exposure.
Proposed state legislation would require that all children be screened for blood-lead levels.
Mandated screening in San Diego County could happen another way.
The San Diego Unified School District, the second largest school district in the state, is initiating water quality testing at all of its schools.
Under California Code of Regulations § 37100(b)(2)(E), if high levels of lead are detected, it could trigger health care providers of public services to investigate if kids have been impacted by the unsafe levels of lead in the water.
The statute says screening could be triggered: “Whenever the health care provider performing a periodic health assessment of a child 12 to 72 months of age becomes aware that, in the professional judgment of the health care provider, a change in circumstances has put the child at risk of lead poisoning.”
The California Department of Public Health has not yet answered an NBC7 question about whether the discovery in lead in the water at La Mirada Elementary in the San Ysidro School District, and at San Marcos Middle in the San Marcos Unified School District, and in Emerson Bandini Elementary School in the San Diego Unified School District, triggers such an investigation.