FIELD-TESTS FOR A REGIONAL MERCURY DEPOSITION NETWORK - SAMPLING DESIGN AND PRELIMINARY TEST-RESULTS

A number of actions have been undertaken within the National Atmospheric Deposition Program (NADP) to implement a regional mercury deposition network. This paper describes a field test designed to evaluate a collector design and protocol for implementation within a new Hg network. The collector chosen for evaluation is a ''dual-orifice'' collector, designed to sample precipitation for mercury and other metals simultaneously. The method chosen for Hg analysis was cold vapour atomic fluorescence spectroscopy (CVAFS). The weekly precipitation Hg concentrations range between 4.29 and 17.88 ng l(-1), with a volume-weighted mean of 10 ng l(-1) comparable to those reported in other ongoing studies in North America and Europe. Calculated deposition flux ranges from 43 to 358 ng m(-2) week(-1), with a mean of 186 ng m(-2) week(-1).