The OP refers to Sudbury, Ontario and the Inco superstack in a misleading manner - the OP lost me at that point. NASA used Sudbury during the Apollo program for Astronauts to become familiar with shatter cones. It is not still used by NASA. Since the superstack was built in 1972 and 90% of the sulfur was removed from the gases before they enter the superstack in the 1990s, the environment is much improved. Having traveled to Sudbury in 1998 for a wedding I can say that Sudbury certainly no longer looks like a waste land (to the extent it ever did).