LAUSR

Abstract Atmosphere inside caves used for speleotherapy are microenvironments influenced by ventilation and human activities inside. In this context, particulate matter with an aerodynamic diameter from 15 nm to 10 μm was collected with an electrical low-pressure impactor ELPI+ in the Cisařska Cave in the northern part of the Moravian Karst (Czech Republic) and 33 elements were determined with inductively coupled plasma tandem mass spectrometry (ICPMS/MS). To see the effect of ventilation, samples were collected with closed and opened entrances. Nucleation mode particles (particles with aerodynamic diameter less than 10 nm) were dominant in particle number concentrations at both cave ventilation regimes. Aitken mode particles (10–100 nm) differed in the content of sulphur, calcium, iron, chromium, magnesium and nickel for different ventilation regimes. Accumulation mode particles (100–1000 nm) consisted predominantly of sulphur and calcium, also chromium, copper, arsenic, molybdenum, selenium, cadmium and lead were mainly present in this particle size range. Coarse mode particles (larger than 1000 nm) contained predominantly calcium, in addition to common earth crust elements, originating by mechanical abrasion of cave floor. It is suggested that ventilation as well as children activities in the cave influence the elemental composition of particulate matter, which might have an impact on speleotherapy.