A paleolimnological survey of combustion particles from lakes and ponds in the eastern Arctic, Nunavut, Canada.

摘要

Recently international attention has been directed to investigation of anthropogenic contaminants in various biotic and abiotic components of arctic ecosystems. Combustion of coal, biomass (charcoal), petroleum and waste play an important role in industrial emissions, and are associated with most human activities. A functional and artificial classification of combustion particles in the arctic environment has been developed and applied in an exploratory paleolimnological investigation of natural and anthropogenic combustion particulates in lake and pond sediments. Combustion particle features are described and artificial and diagnostic keys are presented. Particle photographs are included as an aid to description and identification.; The study sites selected included lakes or ponds at Alert and Cape Herschel, Ellesmere Island, and from the west and east coasts of Hudson Bay, Nunavut, Canada. This broad transect begins approximately 825 km from the North Pole and runs almost 3000 km from Alert to the Belcher Islands. The combustion particle spectra represented in sediments varied widely: with spheroidal carbonaceous and non-carbonaceous particles contributing >90% at the most northerly sites at Alert, and with wood charcoal comprising ∼60% of the combustion particles found at Hawk Lake, Keewatin, and 20 to 45% in the Belcher Island sediments. Recent sediment records showed a decline in the percentage relative abundance of combustion particles of all types at the top of the core at Alert. A similar change was noted at Hawk Lake, where the particle maximum dated to the 1970s. At the Belcher Islands however, the particle maxima occurred at the surface in two of the three sites.; The detection of a range of combustion related particles at the sites studied suggests that these particles may have wider application both as proxies for, and as vectors of, contaminant transport and deposition. While further work is required on a wider spatial scale in order to draw conclusions about causal relationships, we can now say that combustion particles do appear in the sediment records in the Eastern Arctic. More importantly, these particles display spatial and temporal variability that can be correlated with other environmental trends.