210Pb and 226Ra concentrations versus soil depth profiles are used to determine the 210Pb flux from the atmosphere to the earth's surface. A value of 1.6 dpm cm-2 yr-1 is obtained. Other methods of obtaining the 210Pb flux are discussed. Values range from 0.53 to 2.0 dpm cm-2 yr-1 for the north temperature zone. Estimates of continental values range from 0.8 to 2.0 dpm cm-2 yr-1 and oceanic values from 0.53 to 1.0 dpm cm-2 yr-1.