The aim of this study was to determine the impact of mercury pollution on soil, surface water, and sediment ecosystems in the
area of old mercury mines. The study was performed in the touristic area of Sântimbru Băi and Sâncrăieni villages from the
Harghita County, Romania. More than twenty years ago, a mine for the extraction of mercury operated in Sântimbru Băi. The
area was decontaminated, but no monitoring studies have been made for over 15 years. During these original monitoring studies
over four years, soil, surface water and sediment samples were taken upstream and downstream from the studied areas. They
were analyzed in respect with the mercury content by atomic absorption spectrometry. The results showed different mercury
concentration levels in the surface water (between <1.0 and 6.3 μg/L), soil (between <0.02 and 81.81 mg/Kg DW) and sediment
(between <0.02 and 1.859 mg/Kg DW) samples, depending on sampling point and harvesting period. Regarding the soil samples,
it was observed that mercury pollution persists over time in the old mine area, although it was closed down for decades.