A comparison of indigenous mosses and topsoils for use in monitoring atmospheric heavy metal deposition in Galicia (northwest Spain)

Samples of moss (Scleropodium purum or, in its absence, Hypnum cupressiform e) and of topsoil (0-5 cm) were collected in the spring of 1995, from 75 si tes distributed throughout Galicia (northwest Spain) in order to compare th e potential usefulness of each in evaluating the atmospheric deposition of contaminants. Analysis was made of the total content of various metals in t he moss and of different soil metal fractions (including total metal conten t, labile metals and metals bound to organic material). We found that the l abile fraction most closely resembled the metal content of the moss. Calcul ation of enrichment factors allowed us to show that the soil was not, excep t in the case of Cr, the main source of contamination in the moss. By compa ring contamination factors of metals in moss and soil fraction samples we f ound that moss samples were more useful for evaluating the degree of contam ination at different sites. (C) 2001 Elsevier Science Ltd. All rights reser ved.