This paper examines both in-situ production and long-range transport of urban air as sources of marine alkyl nitrates. It is shown that alkyl nitrates are produced fairly rapidly in urban settings and persist for long times. The transport from urban areas can lead to alkyl nitrate concentrates of 4--83 pptv after 120--240 hours. These levels are far higher than those possible from marine in-situ production. Additionally, alkyl nitrates may be more abundant then PAN in remote marine environments. ¿ American Geophysical Union 1989