Swedish perspectives on mercury pollution

A historical review is given of the research on mercury in the aquatic environment. The present state of the art is depicted from the Swedish perspective. The circumstances leading to the discovery of the biological methylation of mercury are discussed, as well as the possible mechanisms and kinetics of the process. Different factors influencing the biomethylation of mercury are also listed. Recent studies on the accumulation of methyl mercury in food chains partly by means of mathematical modeling are described, as is the use of mathematical models to evaluate the outcome of different restoring measures applied to mercury-contaminated bodies of water. Among the current problem areas in which research efforts are concentrated today, atmospheric mercury transport takes the central place because the contamination of fish in small remote lakes as a result of the atmospheric fallout of mercury is a matter of increasing concern in Sweden. The recently discovered biological degradation of methyl mercury, for example, in lake sediments, is another field in which more research is needed. Experiments are reported in which the influence of some ecological factors on the methyl mercury degrading activity is studied.