Blame air pollution for irregular menstrual cycles

According to the researchers, teenage girls affected by the air pollution may have slightly increased chances of menstrual irregularity and longer time to achieve regularity in high school and early adulthood.

The researchers also warned that exposure to air pollution can cause infertility, metabolic syndrome and polycystic ovary syndrome.

"While air pollution exposures have been linked to cardiovascular and pulmonary disease, this study suggests there may be other systems, such as the reproductive endocrine system, that are affected as well," said Shruthi Mahalingaiah, Assistant Professor at Boston University.

The menstrual cycle is responsive to hormonal regulation. Particulate matter in air pollution has demonstrated hormonal activity. However, according to the researchers, it was not known if air pollution was associated with menstrual cycle irregularity, until now.

For the study, published in the journal Human Reproduction, the researchers used health and location data gathered in the Nurses' Health Study 2 plus air pollution exposure metrics from the EPA air quality monitoring system to understand a participants' exposure during a particular time window.

They found exposure to air pollution during high school was correlated with menstrual cycle irregularity.

"Implications on human disease may come through reducing emissions on a global and individual level," Mahalingaiah noted.