Total and methyl mercury concentrations and fluxes from small boreal forest catchments in Finland.
Total mercury (TotHg) and methyl mercury (MeHg) concentrations were studied in runoff from eight small (0.02-1.3 km2) boreal forest catchments (mineral soil and peatland) during 1990-1995. Runoff waters were extremely humic (TOC 7-70 mg l-1). TotHg concentrations varied between 0.84 and 24 ng l-1 and MeHg between 0.03 and 3.8 ng l-1. TotHg fluxes from catchments ranged from 0.92 to 1.8 g km-2 a-1, and MeHg fluxes from 0.03 to 0.33 g km-2 a-1. TotHg concentrations and output fluxes measured in runoff water from small forest catchments in Finland were comparable with those measured in other boreal regions. By contrast, MeHg concentrations were generally higher. Estimates for MeHg output fluxes in this study were comparable at sites with forests and wetlands in Sweden and North America, but clearly higher than those measured at upland or agricultural sites in other studies. Peatland catchments released more MeHg than pure mineral soil or mineral soil catchments with minor area of peatland.
Porvari
Petri
P
Finnish Environment Institute, SYKE, Research Department, PO Box 140, FIN-00251, Helsinki, Finland. petri.porvari@ymparisto.fi
Verta
Matti
M
D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods; D005387:Finland; D008628:Mercury / Q000032:analysis*; D008767:Methylmercury Compounds / Q000032:analysis*; D012621:Seasons; D012989:Soil Pollutants / Q000032:analysis; D014197:Trees; D014874:Water Pollutants, Chemical / Q000032:analysis*
D008767:Methylmercury Compounds; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D008628:Mercury