By Robert Preidt, HealthDay Reporter

FRIDAY, Jan. 26, 2018 (HealthDay News) -- The quality of the air she breathes might have an impact on a teen girl's menstrual cycle, a new study suggests.

U.S. researchers said that exposure to smoggy air could raise teen girls' risk for irregular periods.

"While air pollution exposures have been linked to cardiovascular and pulmonary [lung] disease, this study suggests there may be other systems, such as the reproductive endocrine system, that are affected as well," said lead researcher Dr. Shruthi Mahalingaiah. She's an assistant professor of obstetrics and gynecology at Boston University School of Medicine.

In the study, Mahalingaiah's group looked at data from a major U.S. study on women's health, and compared it to air quality data from the U.S. Environmental Protection Agency.

The investigators found that exposure to air pollution at ages 14 to 18 was associated with slightly higher chances of menstrual irregularity, and a longer time to achieve menstrual regularity in high school and early adulthood.

The study can't prove cause-and-effect, but hormones regulate the menstrual cycle, and particulate air pollution has been shown in other studies to affect hormonal activity, the study authors noted.

Prior research has also linked dirty air with health problems such as infertility, metabolic syndrome (a cluster of heart risk factors) and a gynecologic condition known as polycystic ovary syndrome.

Two experts in women's health said the findings were interesting, but merit further study.

"As we know, there are many causes of irregular menses [periods], and the authors of the study adjusted their results for many confounding variables," said Dr. Mitchell Kramer. He's head of obstetrics and gynecology at Huntington Hospital in Huntington, N.Y.

However, "there are some variables that might not have been accounted for" in the study, Kramer added. So there's still uncertainty as to whether smoggy air might cause irregular periods.

"The exact impact of this on long-term health and reproductive function is not known at this time," he said, "but it certainly warrants further study."

Dr. Mary Rausch is an endocrinologist at Northwell Health Fertility in Manhasset, N.Y. Reading over the findings, she speculated that "the reproductive system of these girls, who are just beginning to get their periods, may be particularly sensitive to the effects of air pollution."

Rausch believes that "the possible link between our environment and the reproductive health of our young women is certainly concerning."

The study was published Jan. 26 in the journal Human Reproduction.

More information: The California Air Resources Board has more on the health effects of air pollution.

SOURCES: Mary Rausch, M.D., Northwell Health Fertility, Manhasset, N.Y.; Mitchell S. Kramer, M.D., chairman, department of obstetrics and gynecology, Huntington Hospital, Huntington, N.Y.; Boston University, news release, Jan. 25, 2018
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