Using Baby Teeth to Measure Metal Exposure Sheds Light on Autism
Higher levels of lead and less of the essential nutrients such as zinc and manganese were found on baby teeth of children with autism, according to a study funded by the National Institute of Environmental Health Sciences (NIEHS). The findings suggest that differences in early-life exposure to metals, or more importantly how a child’s body processes them, may affect the risk of autism.
“We think autism begins very early, most likely in the womb, and research suggests that our environment can increase a child’s risk. But by the time children are diagnosed at age 3 or 4, it’s hard to go back and know what the moms were exposed to. With baby teeth, we can actually do that.” (Cindy Lawler, Ph.D.)
Using Naturally Shed Baby Teeth
With support from NIEHS, Manish Arora, Ph.D. and colleagues previously developed a method that used naturally shed baby teeth to measure children’s exposure to lead and other metals while in the womb and during early childhood. The researchers use lasers to extract precise layers of dentine, the hard substance beneath tooth enamel, for metal analysis. The team showed that the amount of lead in different layers of dentine corresponds to lead exposure during different developmental periods.
Dr. Arora, an environmental scientist and dentist at the Icahn School of Medicine at Mount Sinai in New York, said that autism is a condition where both genes and environment play a role, but figuring out which environmental exposures may increase risk has been difficult.
The method of using baby teeth to measure past exposure to metals also holds promise for other disorders, such as attention deficit hyperactivity disorder.
“There is growing excitement about the potential of baby teeth as a rich record of a child’s early life exposure to both helpful and harmful factors in the environment.” (David Balshaw, Ph.D.)
We definitely agree with Dr. Lawler in that the ability to measure something the children were exposed to long before diagnosis, in this case using baby teeth, is a major advantage.