Air pollution and epigenetic aging among Black and White women in the US

•Novel findings of air pollution and DNA methylation patterns in Black women.•Black women had higher exposure to NO2 and PM than non-Hispanic White (NHW) women.•PM10 and NO2 were associated with higher biological aging in Black women.•Little evidence of associations among NHW women.•Identified 20 CpGs where DNA methylation was associated with NO2 or PM2.5.