A new study shows that children and teens who are exposed to high levels of air pollution caused by traffic may have evidence of a specific type of DNA damage. This DNA damage is called the telomere shortening.

In a study published online in Journal of Occupational and Environmental Medicine, young people with asthma have the evidence of telomere shortening caused by air pollution from traffic."Our results suggest that telomere length may have the potential for use as a biomarker of DNA damage due to environmental exposures and/or chronic inflammation," Dr. John Balmes of the University of California said in the study.

The study used 14 children and adolescents based in Fresno, California, which is the top two city in the United States with harsh air pollution. The researchers of the study assessed the relation between polycyclic aromatic hydrocarbons, an air pollutant from motor vehicle exhaust, and shortening of telomeres, a type of DNA damage typically linked with aging.

In an article published in Science Daily, researchers found out that as the exposure to PAHs increased, telomere length has decreased in a linear fashion. Children and teens with asthma were exposed to higher PAH levels from air pollution than those without asthma.

They found out that the relationship between PAH level and telomere shortening has remained significant after adjustment for asthma and other factors like age, sex, and race/ethnicity was related to telomere length. The study also shows the previous evidence that air pollution actually causes oxidative stress, which could damage lipids, proteins, and DNA.

The researchers of this study have suggested that children could have different telomere shortening regulation than adults. This could mean that they are way more vulnerable to the detrimental effects brought by air pollution.

"Greater knowledge of the impact of air pollution at the molecular level is necessary to design effective interventions and policies," Dr. Balmes said in the study. Moreover, further research could show that telomeres could provide a new biomarker in order to reflect the cellular-level effects of being exposed to such pollution brought by traffic.