Atmospheric iodine, selenium and caesium depositions in France: I. Spatial and seasonal variations

Selenium distribution and speciation in waters of pristine alpine lakes from central-western Pyrenees (France–Spain)

“…33 Lakes presenting the highest sulphate and selenium concentrations are those located over sedimentary rocks containing shales (De-SR lakes group). Their SO 4 2À concentration is higher than concentrations found in rainwaters 24,51 that may thus, similar to S, indicate selenium geological supply as selenium concentrations are typically higher in shales than in granite, limestone or sandstone. 20,21 To evaluate the contribution of geogenic versus atmospheric Se sources, the molar ratio of Se/S measured in lake waters in this study was compared with Se/S ratios calculated for different rock types using a standard database 52 as no data were available for local bedrocks.…”

“…20,21 To evaluate the contribution of geogenic versus atmospheric Se sources, the molar ratio of Se/S measured in lake waters in this study was compared with Se/S ratios calculated for different rock types using a standard database 52 as no data were available for local bedrocks. Molar Se/S ratios measured in lake waters were also compared with Se/S ratios in wet deposition at the Pic du Midi de Bigorre (calculated from the study by Suess et al 24 ) and Adour watershed (calculated from the study by Roulier et al 51 ). The molar ratio Se/S in Pyrenean lakes was in the range of (0.7-6.8) Â 10 À5 (average values per lake groups shown in Table 2) and does not allow us to provide clear discrimination of potential major sources of Se in these lakes.…”

Atmospheric iodine, selenium and caesium depositions in France: II. Influence of forest canopies

“…We reported in Part I. of this study the results of one year monitoring of I, Se and Cs concentrations in rainfall at 27 forest sites all over France (Roulier et al, 2020). In this paper, Part II., 14 of these forest sites representative of various tree species (i.e.…”

“…The study sites and sampling procedure were already presented in Roulier et al, 2020. Briefly, sites are part of the French RENECOFOR network (i.e. National Network for the longterm Monitoring of Forest Ecosystem) managed by ONF (i.e.…”

“…concentrations of Na (used to estimate dry deposition), K (analogue of Cs), I, Se and Cs were already detailed inRoulier et al (2020). Briefly, Na and K were analyzed by ICP-AES with quantification limits of 0.01 and 0.05 mg L_1, respectively.…”