From: A chronology of ratios between black smoke and PM10 and PM2.5 in the context of comparison of air pollution epidemiology concentration-response functions
chemical component
PM10
PM2.5
1970s
late 1990s
carbonaceous
0.5–0.7
0.3–0.4
0.6–0.8
0.3–0.5
secondary inorganic
0.2–0.4
0.25–0.4
0.4–0.6
sea-salt and dusts
0.1–0.15
0.2–0.3
0.05
0.05–0.15