Figure 9. (Color online) Yearly average cerium levels by season in PMF

From

Cerium Levels in Coarse and Fine Airborne Particulate Matter in El Paso, Texas, U.S.A.

Fumador E.A., Amaya M.A., Brunner B., Clague J.W., Li W-W., Olvera H.A., Berwick M., Burchiel S.W., Pingitore N.E.

Journal of Atmospheric Pollution. 2019, 7(1), 1-13 doi:10.12691/jap-7-1-1