Fig. 1
From: Exposure to NO2, CO, and PM2.5 is linked to regional DNA methylation differences in asthma
Panel a shows the relative locations of the air quality monitoring stations (magenta symbols) and the participant home addresses (black circles). Panel b illustrates the variability across monitoring stations (indicated by different symbols as in the legend), which match the shapes of the magenta symbols in panel a for the four studied pollutants (CO, NO2, O3, PM2.5), indicated with different colors as in the legend in panel d, using yearly averages across the study period (2010–2015); the bars show the ranges of the annual averages. Only two monitoring stations reported values for PM2.5. Panel c describes the distribution of the 188 clinic visits across months of the calendar year, and panel d illustrates the seasonal variation in pollutants using monthly averages across monitoring stations, with the bars showing the ranges of the monthly averages across years 2010–2015. Note: In panels b and d, each value is divided by the average for the pollutant overall monitoring stations and years. Also, two stations in close proximity replaced each other, so their data are combined in panels b and d; in panel a, they are indicated by two magenta circles very close together in the middle of the plot