Figure 2From: Seasonal ambient air pollution correlates strongly with spontaneous abortion in Mongolia Calendar monthly averages of ambient air pollutant levels correlated with hours of darkness. (A) SO2. (B) CO. (C) NO2. (D) PM10. (E) PM2.5. Monthly average air pollutant levels are shown as black bars; seasonal hours of darkness during the annual solar cycle of 2011 are shown as grey dots and a connecting line.Back to article page