ATLANTA – A newly published study by researchers from Emory University and Harvard University found a connection between childhood exposure to air pollution and the age at which U.S. girls experienced their first periods.
The study, published in Environmental Health Perspectives, collected data from more than 5,200 girls across the United States—all of whom were children of participants in the Nurses’ Health Study II—found that girls who had higher residential exposure to fine particulate matter air pollution throughout their childhoods tended to have their first periods sooner.
Why these findings matter
Girls who have their first periods at an earlier age face increased risk for several diseases later during their lifetime, including cardiovascular disease, Type 2 diabetes and certain types of cancer.
What can be done
The reproductive health of young girls can be protected, as early as in utero, through enacting policies and regulations designed to reduce the primary sources of particulate matter air pollution, including emissions from gasoline, oil, diesel fuel, and wood combustion.
The questions that remain
More research into potential biological mechanisms is needed to fully understand how exposure to fine particular matter many cause girls to have their first periods at an earlier age. The study also only investigated a single type of air pollutant—particulate matter—but people are exposed to several different types of air pollutants, so additional research is needed to understand how/if multiple air pollutants interact with each other and if this mixture has a different effect on the reproductive health of girls.
What the experts say
Audrey Gaskins, ScD, the study’s senior author and associate professor of epidemiology at Emory University’s Rollins School of Public Health:
“Our study highlights one potential environmental factor—particulate matter air pollution—that may help explain the trend of earlier ages of menarche being observed over the past 50 years. While more research is necessary, it suggests that early life environmental exposures may pay a key role in dictating the pace of reproductive development in girls.”
Robert Hood, PhD, the study’s lead author and a postdoctoral trainee fellow in the Department of Epidemiology at Emory University’s Rollins School of Public Health:
“In our study of girls across the U.S., we found that higher exposure to fine particulate matter, a type of air pollution, was related to earlier menarche. We think that fine particulate matter may disrupt the endocrine system and, in part, lead to earlier menarche in girls. Although, additional research is needed to confirm this.”