Concentrations of Na, Cl, Br, and I in aerosols and Cl, Br, and I in inorganic gases were measured in the marine atmosphere off the west African coast (~0¿N, ~0¿W) in June 1977 an used to estimate their mean lifetimes and rates of production. Mean concentration (in micrograms per cubic meter) during an 8-day, stable, rain-free period of the voyage follows; for particulate Na 4.0, Cl 5.3, Br 0.017, and I 0.004; for inorganic gas Cl 1.0, Br 0.012, and I 0.013. The results of a steady state analysis suggest a ~3-day mean residence time for the marine aerosol during the period of our observations, a ~667 μg m-2 d-1 loss rate of Cl (probably as HCl) from the marine aerosol, and a subsequent ~2 1/4-day mean residence time in the marine atmosphere. A similar analysis for gaseous inorganic Br gave a ~2 1/2μg m-2 d-1 mean loss rate from the marine aerosol and a ~7-day mean residence time. Computed dry deposition coefficients were (in centimeters per second) ~0.4 for the marine aerosol, ~0.77 for gaseous inorganic Cl, and ~0.24 for gaseous inorganic Br.