A new US study has shown that smog and poor air quality could affect teens' menstrual cycles, at the time when they are fist begin to menstruate.

Lead researcher Dr. Shruthi Mahalingaiah, assistant professor of obstetrics and gynecology at Boston University School of Medicine explains that studies have shown a connection between smog and cardiovascular and pulmonary disease but that other bodily systems may also be affected by poor air quality. The study suggests that the endocrine reproductive system could be affected by smog.

For the study, researchers looked at data from a women’s health study and compared it to reports on air quality from the EPA, Environmental Protection Agency. The study found indications that exposure to air pollution in teens 14 to 18 led to increased chances of irregular menstrual cycles as well as a longer time to achieve regularity in high school and early adulthood.

There are different standards for irregular periods, including cycles that occur more frequently than every 21 days or last for longer than 8 days. Missing, early, and late periods are other symptoms of an irregular menstrual cycle.

Although the study didn’t prove cause and effect, other studies have shown that smog affects hormones. In other studies, poor air quality has been linked to infertility, various health conditions, heart health issues and polycystic ovary syndrome.

Experts in women’s health have said that the results of the study show promise but although the researchers adjusted for different variables, not all variables may be accounted for. This means that further research is needed before any definitive conclusion is reached.

Other experts have said that the girls in the study may be especially sensitive to the effects of smog because they have only just started their reproductive cycles. However, that there could be a link between environment and reproductive health is very concerning.

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