Exposure to even miniscule levels of carbon monoxide during pregnancy can have an adverse impact on fetal brain, resulting in permanent impairment, a new study has revealed.
"We expected the placenta to protect fetuses from the mother's exposure to tiny amounts of carbon monoxide," said John Edmond, professor emeritus of biological chemistry at the David Geffen School of Medicine at UCLA.
"But we found that not to be the case," he added.
During the study, the researchers exposed pregnant rats to 25 parts per million carbon monoxide in the air, a level considered safe.
Dr. Ivan Lopez, UCLA associate professor of head and neck surgery, tested the rats' litters 20 days after birth.
He found that rats born to animals who had inhaled the gas suffered chronic oxidative stress, a harmful condition caused by an excess of harmful free radicals or insufficient antioxidants.
"Oxidative stress damaged the baby rats' brain cells, leading to a drop in proteins essential for proper function," said Lopez.
"Oxidative stress is a risk factor linked to many disorders, including autism, cancer, Alzheimer's, Parkinson's, Lou Gehrig's disease, multiple sclerosis and cardiovascular disease. We know that it exacerbates disease," he added.
"We believe that the minute levels of carbon monoxide in the mother rats' environment made their offspring more vulnerable to illness," said Edmond.
"Our findings highlight the need for policy makers to re-examine the regulation of carbon monoxide," the expert added.
Tobacco smoke, gas heaters, stoves and ovens all emit carbon monoxide, which can rise to high concentrations in well-insulated homes. Infants and children are particularly vulnerable to carbon monoxide exposure because they spend a great deal of time in the home.
The findings appear in journal BMC (BioMed Central) Neuroscience.