Toxic Sludge question

Was playing with the Rook City environment and the Toxic Sludge card came up and there was some confusion about its use. The text says “At the start of the environment turn, each player may discard 1 card to destroy 1 environment card.” Does this mean that the players can discard additional cards to destroy multiple environment cards (including the toxic sludge itself) or does this mean that only one environment card may be destroyed per turn?

Each player has the choice, so you could collectively end up destroying as many environment cards as there are players.