The particulate heavy metal concentrations of Cr, Fe, Ni, Cu, Zn, Cd, Tl, and Pb were determined in the atmosphere over the Atlantic Ocean from 60 ¿S to 54 ¿N with the definitive method of isotope dilution mass spectrometry. The samples were collected during an expedition with the German polar research ship Polarstern. The sampling and the sample treatment were carried out under strict contamination control. Fe was used as a reference element for the influence of crustal material calculating the corresponding enrichment factors EF(Fe) for the other metal traces. The heavy metal concentrations varied up to more than 3 orders of magnitude, which represents the different natural and anthropogenic sources and influences on the composition of the marine aerosol. Tl showed the lowest abundance of all heavy metals with concentrations of less than 20 pg m-3 for all samples except those from the area around the English Channel. The concentration ranges for the other elements were Cr=<0.08--9 ng m-3, Fe=<2.6--7500 ng m-3, Ni=<0.05--10 ng m-3, Cu=<0.02--20 ng m-3, Zn=<0.9--450 ng m-3, Cd=<0.003--3.5 ng m-3, and Pb=<0.05--200 ng m-3. The lowest element concentrations were usually measured in the remote areas of the South Atlantic, whereas the highest ones were detected around the English Channel.

However, at some sampling sites over the North Atlantic, very low Cd and Pb values in the range of 6--20 pg m-3 and <0.5 ng m-3, respectively, were determined, which could be attributed to Arctic air masses by their corresponding backward trajectories. Due to high Fe concentrations, a substantial influence of crustal material was observed in the atmosphere southeast of the South American continent, in the South Atlantic area of the southeast trades, and over the North Atlantic west of North Africa. EF(Fe) values for the most part less than 10 for Cr and Ni and less than 50 for Cu indicate that the influence of crustal material for these metals is much higher than for Zn, Cd, and Pb where EF(Fe) values between 500 and 5000 had often been determined. This is due to anthropogenic and biological influences. The anthropogenic influence was clearly identified, e.g., over the South Atlantic near the La Plata area, in the English Channel, and over the North Sea, whereas a substantial biological influence could be observed over the South Atlantic in the area of the southeast trades. ¿ American Geophysical Union 1990