Use of msses as collectors of airborne heavy metals near a smelting complex

Moss bags are used as collectors of airborne heavy metals in the region surrounding the Zn and Pb smelting complex at Avonmouth, near Bristol, U.K. A land area of 660 km' is studied by exposure of 250 freshly prepared Sphagnum moss bags for 6-week periods. The results are presented as a series of squares computer drawn on maps of the area. Concentrations of metals in exposed mosses range from 4800 ppm Pb, 8200 ppm Zn and 200 ppm Cd, ≈ 700 m from the smelter, to insignificant levels in areas of Wales further than 15 km from the smelter. Metal concentrations are high within the zone of the prevailing winds from Avonmouth, where Pb and Cd values exceed background levels approximately 15-fold, as far as 15 km from the smelter.