Long-term exposure to air pollutants can greatly increase the risk of developing dysmenorrhea, a condition in which people experience severe cramps and period pain, according to a new, important study that decodes the role air pollution plays in menstrual cycle function.

Dysmenorrhea is a wildly common gynecological condition, affecting almost 16-91% of people of reproductive age. The painful and severe periods are believed to be a result of hormonal imbalances or underlying conditions such as endometriosis or inflammatory diseases. Out of the women diagnosed with dysmenorrhea, 2-29% attest to experiencing symptoms severe enough to restrict daily activity.

This is the first time researchers have been able to link exposure to a cluster of air pollutants — such as nitrogen, carbon oxides, and fine particulate matter — to the pain and cramps experienced during a menstrual cycle, adding data-backed insight into the role environmental factors play.

“…here we demonstrate for the first time another important risk factor for developing dysmenorrhea: air quality, in particular long-term exposure to pollution,” said Prof Chung Y. Hsu at the College of Medicine, one of the authors from China Medical University, Taiwan in a press release. “We don’t yet know the underlying mechanism, but emotional stress in women exposed to air pollutants, or higher average levels of the hormone-like prostaglandins in their body, might be part of the answer.”

Published in Frontiers in Public Health, the longitudinal study explored the health data of 2,96,078 women and girls between 16-55 years old in Taiwan. They correlated it with long-term air pollution data between 2000-2013. None of the participants had a history of dysmenorrhea before the survey began. The researchers found that during these 13 years, 4.2% of women and girls surveyed were diagnosed with dysmenorrhea for the first time.

But the overall conclusion was more jarring: the risk of developing dysmenorrhea was up to 33 times higher among women and girls who lived in areas with the highest levels of air pollutants — as compared to others exposed to lower levels of pollutants.

“Our results demonstrate the major impact of the quality of air on human health in general, here specifically on the risk of dysmenorrhea in women and girls,” Prof. Hsu noted.

Related on The Swaddle:

Lockdown Stress Is Disrupting Menstrual Cycles

The findings weigh in our understanding and handling of public health. South Asian countries, like Taiwan and India, are among the worst affected by air pollution — about 60% of people in India are estimated to be exposed to long-term effects.

Clearly, the public health burden is more nuanced and gendered than we realize. A few studies in the past have considered air pollution’s effects on menstrual health. A 2018 study showed teen girls were more likely to experience menstrual irregularity and longer time to achieve regularity in high school and early adulthood if exposed to air pollution. Others have linked air pollution to longer cycles, external factors like stress, reproductive health, and even the lockdown. The negative health effects from air pollution exposure previously known are infertility, metabolic syndrome, and polycystic ovary syndrome.

This points to the underlying idea that menstrual health is not solely a biological phenomenon. It is impacted by an individual’s social conditions, such as income and the area they live in. In the present study, researchers found younger women, women of lower incomes, and living in more urbanized areas tended to have a higher risk of developing dysmenorrhea. The greatest individual effect was from long-term exposure to high PM2.5 — these are fine, inhalable particulate matter that is associated with air pollution.

In 2019, India had the worst PM2.5 concentration in the world. The findings map out the different menstrual cycles experienced by women and girls living in urban and rural areas — showing the increased exposure to air pollutants in low-income areas greatly increased their risk of dysmenorrhea.

This is coupled with the reality of period poverty, which still plagues a large part of rural India along with other countries. Most girls and women miss out on schools and work due to inaccessibility to resources and lack of awareness – and increased pain due to dysmenorrhea only serves to exacerbate the issue.

A study published in 2017 pointed out the vitality of identifying environmental factors that affect the menstrual cycle — “from the perspective of public health, because it may have important implications for population health, namely infertility, reproductive cancers, osteoporosis, and metabolic disorders.”

Prof. Hsu summarized the need for viewing steps to mitigate air pollution in alignment with the public health: “This is a clear illustration of the need for actions by governmental agencies and citizens to reduce air pollution, in order to improve human health.”