Effects of Exposure Duration and Exposure Levels of Ambient Air Pollutants on the Risk of Polycystic Ovarian Syndrome: A 2015–2019 Korean Population-Based Cohort Study

Abstract

Exposure to ambient air pollution is associated with an increased risk of menstrual disorders and infertility. This study examined the relationships between the levels and duration of air pollution exposure and the risk of polycystic ovarian syndrome (PCOS) using Korean population-based cohort data (2015–2019). Real-time data on PM10, PM2.5, O3, CO, SO2, and NO2 were provided by the Korean Ministry of Environment. The average monthly air pollutant concentration from 1 January 2014 to 31 December 2018 was analyzed. To assess individual-level exposure to air pollutants, a spatial prediction model and an area-averaging approach were used. In total, 237,582 PCOS cases were analyzed. The annual age-adjusted PCOS incidence was 6.70, 8.28, 9.73, 11.58, and 11.97% from 2015–2019, respectively. The PCOS risk increased 1.29–1.32, 1.43–1.52, and 1.32-fold following exposure to the 2-year and 3-year average levels of PM2.5, O3, and NO2, respectively, compared to their 1-year average levels. The PCOS risk increased 1.75-fold (95% confidence interval: 1.66–1.85) in the fourth-quartile for the NO2 level. Increased SO2 and CO levels in the second- and third-quartiles were also associated with an increased PCOS risk. Exposure to air pollutants thus increased the risk for PCOS in the Korean population.

A Systematic Review of Microparticulate Air Pollution in Polycystic Ovary Syndrome

“…Air pollution is an increasing global problem that has been associated with a wide variety of human diseases, including PCOS (5,(29)(30)(31)(48)(49)(50). Air polution consists of a range of components including gases (SO2, NOx, NO, NO2) and suspended particulates of different sizes.…”

“…Microparticulate air pollution is believed to account for a large proportion of the public health impact of air pollution, including reproductive diseases (50,52). MAP has been associated with menstrual irregularity (53), infertility (25,30), adverse pregnancy outcomes (31), increased incidence of PCOS (5,29), and has also been linked to transgenerational transmission and infant weight gain (54,55). Human studies have shown that metabolites of tobacco (cadmium, cotine) can be found in ovarian follicular fluid and may potentially affect the developing egg (42,53).…”

“…Chronic low-grade systemic inflammation can occur when there is a persistent stimulus that results in failure of homeostatic mechanisms, and is a cornerstone of PCOS pathophysiology (3). MAP can act as a persistent chronic inflammatory stimulus, and has increasingly been recognized as a risk factor in the pathogenesis of PCOS (5,29,30).…”

“…The authors concluded that women exposed to high concentrations of air pollutants, including microparticulate matter, had a high risk of developing PCOS. (29) This retrospective population-based cohort study examined the relationship between the level and duration of air pollution exposure and the risk of developing PCOS (29). Data were extracted from the Korean National Health Information Database (NHID) which provides comprehensive medical services to all Koreans.…”