This study presents size-resolved mass concentrations of inorganic ions, levoglucosan, and total carbon of aerosol particles from a coastal station at the Dutch Wadden Sea as well as isotopic signatures (¹³C and ¹⁴C) of organic carbon. Aerosol advected out to the North Sea consists mainly of ammonium nitrate and carbonaceous material. Fossil sources contribute a small mass fraction to organic carbon. ¹³C signatures differ strongly from those of primary sources, highlighting secondary processes.