A Lead (Pb) Mass-Balance Budget for a Dry Periglacial Catchment in West Greenland : Discussing the fate of pollutant Pb
Abstract: Lead (Pb), occurs both naturally and as a pollutant in Arctic landscape systems. The ongoing climate change, especially pronounced in the Arctic, changes the premises for Pb transport and mobility. Thus, to predict future development of both natural and pollution Pb, an increased understanding of their storages and flows in an Arctic system is of interest. Here, a Pb mass-balance budget for an entire catchment in West Greenland was calculated. The budget shows that most Pb is stored in terrestrial soils (94%), while 6% of total catchment Pb is in lake sediments. Other Pb-pools are small in comparison (<1% combined). The entire catchment system has a negative balance, with annual inputs of 44 g Pb from precipitation and 67 g Pb from eolian deposition, while 150 g Pb is removed from the system (through sedimentation). Limited lake water outflow (o.15 g Pb yr-1) suggests that the catchment in its entirety acts as a Pb-sink. The terrestrial system, however (wet deposition input of 34 g Pb and hydrological export of 68 g Pb annually), is considered to be a Pb-source to the aquatic system. The magnitude of hydrological and eolian transport is similar, however the former is more important for pollution Pb transport where the latter is more important for natural Pb. The fate of pollutant Pb is determined by future climate change. Wetter conditions could lead to a prolonged export of Pb further down-stream. If drier conditions prevail, eolian transport will be more important and pollution Pb could stay in soils.
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