anchor: For mercury, the 1996 National Toxics Inventory was modified based on the 1999 information collection effort for coal utilities and the 2002 MACT implementation for medical waste incinerators, and the 2000 MACT implementation for municipal waste combustors was used.
positive: The 1996 National Toxics Inventory was modified based on information collected in 1999.
negative: The National Toxics Inventory has not been modified since 1996.