In this project, we quantify the atmospheric gaseous elemental mercury (GEM) concentrations in Idrija, the former mercury mine and the cement production facility, Salonit-Anhovo, located in Slovenia using three air Hg monitoring techniques, namely; the Tekran system, Lumex RA-915M, and biomonitoring using lichens. Hg emission data were recorded from the cement facility. Continuous GEM atmospheric concentration measurements were performed using the Tekran system over one year (December 6, 2019 ‒ December 31, 2020) at Vodarna in the cement plant vicinity. GEM concentration values recorded from the Tekran system range from 0.1 ng/m3 ‒ 29.5 ng/m3. Wind direction plays an important role in atmospheric Hg concentrations. The analysis revealed that strong winds in the direction of the Vodarna from the cement plant and high levels of Hg emissions from the plant emanating influenced high GEM concentrations in this particular sampling location. GEM concentrations were also measured using the Lumex detector at all sampling locations. GEM concentrations in the vicinity of the former Idrija smelting plant recorded higher values (up to 78.2 ng/m3) compared to values recorded at the cement plant vicinity and the reference location on Pokljuka (up to 2 ng/m3). Also, a comparison of the past and present measurement trends of Hg in air showed a decrease from 20 000 ‒ 14 ng/m3 at the smeltery site and 6 000 ‒ 4 ng/m3 within the Idrija town between 1974 ‒ 2020. THg in in situ (Punctelia subrudecta and Flavoparmelia caperata) and transplanted lichen samples (Hypogymnia Physodes) were conducted for a period of 3 and 6 months respectively. Lichens were analysed after proper preparation by AAS detector Model Hg-201 Semi-automated Hg Analyzer. Results from both the in situ and transplanted lichens showed that lichens are very sensitive to air contamination and are known to accumulate compounds and elements in amounts that closely correlate with atmospheric levels. Also, after comparing the results of THg in lichens and GEM measurements using the air active measurements, a strong positive correlation was obtained, indicating that lichens can be used as a cost-effective technique for Hg monitoring.

{"references": ["Kocman, D., Horvat, M., 2011. Non-point source mercury emission from the Idrija Hg-mine region: GIS mercury emission model, J. Environ. Mgmt, 92, 2038-2046,", "Kocman, D., Vre\u010da, P., Horvat, M., 2011. Atmospheric distribution and deposition of mercury in the Idrija mine region. Environ. R. 111, 1-9.", "Kotnik, J., Horvat, M., Dizdarevic\u02c7, T., 2005. Current and past mercury distribution in air over the Idrija Hg mine region, Slovenia. Atmos. Environ. 39, 7570\u20137579.", "Ljubi\u010d-Mlakar, T., Horvat, M., Kotnik, J., Jeran, Z., Vuk, T., Mrak, T., Fajon, V., 2011. Biomonitoring with epiphytic lichens as a complementary method for the study of mercury contamination near a cement plant. Environ. Mon. Assess. ISSN 0167-6369, 181, 225-241.", "Mlakar, T, L., Horvat, M., Vuk, T., Stergar\u0161ek, A., Kotnik, J., Tratnik, J., Fajon, V., 2010. Mercury species, mass flows and processes in a cement plant. Fuel 89, 1936\u20131945.", "Sholupov, S., Pogarev, S., Ryzhov, V., Mashyanov, N., Stroganov, A., 2004. Zeeman atomic absorption spectrometer RA- 915C for direct determination of mercury in air and complex matrix samples, Fuel Process. Technol., 85, 473\u2013485.", "Poissant, L., Hoenninger, G., 2004. Atmospheric mercury & ozone depletion events observed at the Hudson Bay in Northern Qu\u00e9bec along with BrO (DOAS) measurements. RM Z-. Materials and Geoenvironment, 51, 1722\u20131725.", "Tekran, 2001. Model 2357A Principles of Operation, Tekran", "UNEP, 2018. Global Mercury Assessment 2018 report. UN-Environment Programme, Chemicals and Health Branch, Geneva, Switzerland.", "Streets, D, G., Horowitz, H, M., Jacob, D, Z. Lu, L. Levin, A, F, H., E. Sunderland, E, M., 2017. Total Mercury Released to the Environment by Human Activities. Environ. Sci. Technol. 51, 5969-5977.", "UNEP. Global Mercury Assessment, 2013. Sources, Emissions, Releases, and Environmental Transport; UNEP Chemicals Branch: Geneva, Switzerland."]}