Association between air pollution and menstrual disorder outpatient visits: A time-series analysis

Menstrual disorders are common diseases among reproductive-aged women with increasing concerns. Until now, there have been limited studies about the association between menstrual disorders and air pollution. This study aimed to investigate the association between short-term (concurrent day and within 1 week prior) ambient air pollution exposure and menstrual disorder outpatient visits in Xi'an, a metropolis in northwestern China. Daily baseline outpatient data of menstrual disorders from January 1, 2010 to February 18, 2016 (2239 days) were obtained. An over-dispersed Poisson generalized additive model was applied to discover the relationship between short-term air pollution exposure and the number of menstrual disorder outpatient visits by adjusting the day of the week and weather conditions. A total of 51,893 outpatient visits for menstrual disorders were recorded. A 10 μg/m³ increase of PM₁₀ and NO₂ concentrations corresponded to 0.236% (95% Cl: 0.075%, 0.397%) and 2.173% (95% Cl: 0.990%, 3.357%) elevations in outpatient-visits for menstrual disorders at lag 7 and lag 01 (concurrent day and previous 1 day), respectively. The association was more significant in young females (18-29 years) and there was no obvious association observed between SO₂ and menstrual disorder outpatient visits. This is the first evidence that short-term exposure to ambient air pollution can be associated with an increased risk of menstrual disorder attacks. The results of our study may help to establish more comprehensive understanding of the health effects of ambient air pollution on menstrual disorders and other reproductive diseases.