A new study from the American Journal of Public Health finds that prenatal exposure to cigarette smoke can impact parts of chromosomes in children.

Researchers investigated telomere length, a repetitive DNA sequence located at the ends of chromosomes that stabilizes the chromosome. Telomeres are a part of chromosomes that have been identified as a biomarker of cellular aging.

After reviewing results from more than 100 New Orleans children aged 4 to 14, researchers found that telomere length was shorter among children who were exposed to smoke during pregnancy. Short telomere length has been associated with negative health outcomes.

"Stress exposure, both environmental and psychosocial, during prenatal life may result in biological changes that alter developmental trajectories and may alter lifelong health trajectories. Identifying the earliest developmental time points for prevention and intervention is challenging but critical if we expect to improve health outcomes," the study's authors conclude.