Contact Information

Department of Environmental Sciences
P.O. Box 65 (Viikinkaari 1)
00014 University of Helsinki

Niemenkatu 73
15140 Lahti

Heavy metals in the environment


Martin Lodenius, Esa Tulisalo, Heinz-Rudolf Voigt

Special emphasis has been put on spreading, behaviour and bioaccumulation of mercury (Hg) and cadmium (Cd), but also other metals have been studied (e.g. Fe, Zn, Ni, Cu, Pb). We are mainly by using biomonitoring methods but we have also done some in vitro experiments and review and editorial works on trace elements and metalloids.

moss bags


The research is mainly focussed on the following topics:

 

  • Atmospheric transport and deposition of mercury using bioindicators

    Mercury is readily taken up by plant tissues and strongly retained. This can be used for monitoring purposes as well as for estimation of deposition rates. Also the ratios between dry and wet deposition have been estimated. Commonly occurring mosses (e.g. Pleurozium and Hylocomium) and lichens (e.g. Hypogymnia) have been proved to be reliable biological indicators. Moss bags offer a standardized method for accurate measurement of metal deposition.

  • Sorption, desorption and mobilization of metals in soils
Soil conditions - including pH, organic matter and physical composition - affect the binding of heavy metals in soils. Physical activities like ditching of peatlands and forest soil preparation may increase the leaching of several metals. In Finland, high concentration of mercury have been recorded in fish from man-made lakes. Also ash fertilizing and changes in e.g. pH may increase the mobilization and cause increased uptake of heavy metals in biota.

mushroom

  • Distribution, uptake and bioaccumulation of metals in terrestrial food chains using plants, macrofungi, earthworms, insects, birds and mammals.
    The uptake of metals in plants is highly variable depending on plant species and environmental conditions. Some edible macrofungi show an extremely high uptake of cadmium and mercury which is of concern for public health. The role of insects and other invertebrates in cycling of heavy metals may be of crucial importance but is still poorly known. Bioaccumulation of mercury occurs especially in aquatic food chains with high concentrations in e.g. sea eagles, ospreys and otters.

  • Distribution, uptake and bioaccumulation of metals in aquatic food chains using sediments, aquatic plants and fish.

    Mercury pollution from the 1960's is still seen in sediment layers from that period. In fish, the concentrations are highest in predatory species. The levels depend on several factors including pollution history, water chemistry, fish age and trophic status.

    fish

  • Relations between metal concentrations, eutrophication and condition of fish in the Baltic Sea.

    Concentrations of several metals have been analysed from many fish species from different parts of the Baltic Sea including Finland, Estonia and Germany. High concentrations of cadmium found at certain locations in southern Finland require further investigations. A negative correlation has been found between the concentrations of mercury and the condition factor (CF) from most of the investigated fish species.

  • Uptake of mercury in man using human hair.

    The main exposure of mercury is via fish and especially predatory fish. In most cases there is a significant positive correlation between fish consumption and mercury concentrations in hair. For most people in Finland the dietary exposure to mercury is low or moderate while the hair concentrations measured in Tucuruí, Brazil were high enough to cause adverse health risks.

Heavy metals are analyzed in our laboratory by using atomic absorption spectrometry (AAS). Our equipment: Varian SpectrAA-400 (flame and electrothermal heating) and Milestone DMA-80 Mercury Analyzer (cold vapour).

Recent publications


Contact information:

  • Martin Lodenius, e-mail: martin.lodenius(at)helsinki.fi, home page
  • Esa Tulisalo, e-mail: esa.tulisalo(at)helsinki.fi
  • Heinz-Rudolf Voigt, e-mail: heinz-rudolf.voigt(at)helsinki.fi, home page