3 Min Read (Reuters) - The most widespread type of dam used to store mine waste is nearly twice as unstable as the average tailings facility, a global study showed on Friday, highlighting the risk of so-called “upstream” construction techniques that some countries have banned. FILE PHOTO: A view of the Brazilian mining company Vale's tailings dam, two years after it collapsed, in Brumadinho, Minas Gerais state, Brazil, January 23, 2021. Picture taken with a drone January 23, 2021. REUTERS/Leonardo Benassatto Concern over tailings dams intensified after the deadly collapse of Vale’s Brumadinho upstream facility in January 2019. Some 10% of all the facilities surveyed had reported a stability issue, the authors found, but that figure jumped to 18.3% for active upstream facilities.