Idrija is a small city well known for its 500 year mining history of mercury (Hg) in the second largest Mg mine in the world. The impact of Hg in Idrija is still very prominent, despite the fact that the mining stopped more than 30 years ago. In the past thirty years lots of attention is paid to Hg in the environment due to its toxicity. Several years of mining in Idrija left a significant impact on the environment, soil and human health. Mercury (Hg) is chemically very active and present in the chain of biogeochemical cycling and global spreading. Hg can undergo several chemical transformations in environment and can accumulate in the food chains with biomagnification pattern.
Today the concentration of Hg in the soil at the near vicinity of Idrija still exceed the legal limits (0.05 mg kg-1 of dry matter), but are lower than during the mining period.
The master's thesis aimed to investigate whether selenium affects the uptake and transport of mercury through the food chain. First, we examine how different concentrations of Hg and Se affect plant growth and Hg and Se uptake in plants. The substrate was contaminated with different concentrations of Hg and put in the pots where the lettuce was planted. After 14 days of growth the salad was foliarly sprayed with solution of selenium.
Furthermore, we were interested in concentrations of Hg and Se in crustaceans, isopods, which were fed with lettuce treated with different combinations of Hg and Se.
The results show that foliar spraying with Se lowers Hg concentrations in plants and therefore further in the food chains. Biofortification of plant with Se may therefore contribute to reduction of Hg load in animals and humans.