Trace metal and major ion composition of precipitation at a North Sea coastal site

Abstract

Major ion and trace metal (Zn, Cu, Cd, Pb, Fe, Mn) concentrations have been determined in 32 rainfall events at a North Sea coastal site over a period of 14 months (June 1987–July 1988). Precautions have been taken to avoid trace metal contamination. Trace metal depositions are positively correlated to excess sulphate deposition; the exception is Cd for which no clear relationship is evident. This is probably due to contamination of the samples with respect to Cd. The highest trace metal concentrations are associated with small rainfall events and with the occurrence of fog and mist. Trace metal concentrations (volume weighted average) are in general agreement with earlier data. For Cd and Zn, however, they are lower and consequently it is suggested that estimates of annual deposition be revised downwards.