A CRITICAL-EVALUATION OF THE USE OF NATURALLY GROWING MOSS TO MONITOR THE DEPOSITION OF ATMOSPHERIC METALS

Mosses have been used extensively to monitor atmospheric deposition of heavy metals and other trace constituents. In this paper, evidence from multi-element moss surveys is used to discuss the feasibility of this technique and to critically evaluate factors that may lead to misinterpretation of results. Two aspects receive particular attention: (1) calibration against precipitation data to allow transformation of element concentrations in moss to deposition rates and (2) contribution to the elemental composition of the moss from sources other than air pollution, such as marine influence, windblown soil dust, and uptake from soil via higher plants and subsequent transfer to mosses. Specific problems with the use of mosses as biomonitors in the Arctic are also discussed.