The distribution of smelter related elements in humus represents the historical record of contamination in the Flin Flon area. The base metal mining and smelting complex has been in operation since the early 1930's, processing ore from local mines, and has undergone many changes during its history in order to streamline processing and comply with modern environmental standards.

The proportional dot maps of As, Cu, and Hg in humus exhibit a "bull's eye" dispersal pattern, centered in the vicinity of the smelter. Maps of Cd, Pb and Zn also reflect this general pattern. For these elements, concentrations are anomalously high at the centre of the contaminated area, and decrease with distance from the smelter according to an inverse curvilinear relationship, thus implicating the smelter as the source. The relationship is such that the log-concentration of the emitted metal decreases directly with the increasing log-distance from the stack until background values are reached. All the non-smelter related elements, including Ni and Cr, show no relationship with distance from the smelter but appear to be related to regional variations in the geochemistry of the underlying substrate and to local variations in the nature of the humus layer.