As part of a regional surficial geological mapping and geochemical prospecting project conducted by the Geological Survey of Canada under the NATMAP Shield Margin Project, humus and till samples were collected at over 2000 sites in the Flin Flon - Snow Lake area. The study area is situated in the vicinity of a remote source of anthropogenic pollution, the base metal smelting complex operated by Hudson Bay Mining and Smelting Corporation at Flin Flon, Manitoba (55 N, 102 W). The geochemical database provides a unique opportunity to examine the nature and regional distribution of heavy metals emissions in the surficial environment, and the relative contribution of these metals from natural and anthropogenic sources.