I livelli di radioattività rinvenuti nella crioconite, il sedimento scuro che si accumula sulla superficie dei ghiacciai durante la stagione estiva, sono elevati. E’ il risultato emerso da uno studio realizzato sul Morteratsch, nei Grigioni, e su quello dei Forni, in Valtellina da studiosi italiani, polacchi e inglesi.
La ricerca è stata recentemente pubblicata sulla rivista "The Cryosphere" ed evidenzia come il cesio-137 sia presente anche in ambienti considerati incontaminati e rivela come le Alpi abbiano subito una forte contaminazione dopo l’incidente di Chernobyl nel 1986. Un po' di sostanza radioattiva dall'Ucraina è arrivata anche di recente, trasportata dalle masse d'aria che hanno trasportato il fumo degli incendi sviluppatosi nelle foreste attorno alla centrale nucleare.
La presenza di altri radionuclidi, come gli isotopi di plutonio e americio o il bismuto-207, è invece riconducibile ai test nucleari effettuati in alta atmosfera negli anni '50 e '60 del secolo scorso.
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