Uptake in Hylocomium splendens and Sphagnum fuscum, of Zn, Cu, Cd, and Pb from artificial solutions of precipitation at ambient concentration levels was investigated. The primary objective was to study to what extent major cations and possibility anions in the precipitation might affect the uptake by competition or possibly by complexing reactions. In addition the effect on metal uptake of pH and temperature was studied. The uptake of Zn and partly Cu was lower from precipitation with a high content of seasalt. With increasing metal concentration an increasing amount of Zn and Cu accumulated in the moss. These observations suggest that cations in the precipitation such as Na(+) and Mg(2+) may affect the uptake by competition. Possibly also Cl(-) may interfere by complexing reactions. Uptake of Zn and Cd was pH dependent. The uptake of all four metals increased with temperature. The results from this work appear to be significant with respect to the interpreation of data from atmospheric deposition surveys based on moss analysis.