237 - Comparison of Yearly Atmospheric Mercury Monitoring with Passive Sampling, Biomonitoring and Active Measurements

Atmospheric mercury (Hg) and its emissions into the atmosphere have received considerable attention in the environmental research community due to its importance in perturbing the Hg biogeochemical cycle. Within the MercOx project, a one-year sampling campaign took place in Slovenia in two different Hg-polluted and industrialized areas. The first area was in the vicinity of the Anhovo cement plant and the second near the former Hg mine in Idrija. An additional sampling area was in Pokljuka, which is considered a remote, industrially-intact sampling site. A total of 8 monitoring sites were selected and three different atmospheric Hg monitoring methods were used: passive sampling (3 sites), biomonitoring-lichens (8 sites) and active measurements (8 sites). Passive samplers and biomonitoring with lichens can present a cost-effective alternative to traditional atmospheric Hg monitoring. Three different passive samplers and transplanted epiphytic lichens (Hypogymnia physodes) were deployed for different time periods and their total Hg content (THg) was measured at the end of each time period. Additionally, in-situ epiphytic lichens were measured at all sites. Meanwhile, periodic active measurements of atmospheric Hg0 were performed using a Lumex RA 915M detector. Comparison of passive sampling and active measurements showed good agreement between the results. The results obtained by passive sampling were usually the most repeatable in the case of longer exposure periods and at the monitoring site with highest average Hg0 concentrations. Comparison of transplanted lichens and active measurements indicated that the correlation between THg concentration in transplanted lichens and atmospheric Hg0 concentration is linear, with better linear correlation at longer exposure times (especially at low atmospheric Hg0 concentrations). In-situ lichens and their THg concentration similarly showed a linear correlation with atmospheric Hg0 concentration. Although variability of the results remains to be addressed, both passive sampling and lichens have shown promising agreement with active measurements and can be used effectively as indicators of atmospheric Hg0 concentrations.

Authors: Jan Gačnik, Igor Živković ,Jože Kotnik, Dominik Božič, Maaire Gyengne Francis,Sabina Berisha, Antonella Tassone, Attilio Naccarato, Nicola Pirrone ,Francesca Sprovieri, Milena Horvat