Mongabay: Toxic red sludge, a waste product of aluminum production, has reached Europe’s Danube River after a spill at a Hungarian factory drowned four people and left over a hundred injured, many with chemical burns. The Hungarian Academy of Sciences says tests show that heavy metals in the Danube due to the spill are currently far from dangerous levels, however other rivers, villages, and farmlands have been devastated by the environmental disaster which released approximately a million cubic meters …