An evaluation of the terrestrial transport, transformations and ecological effects of phosphorus red phosphorus-butyl rubber (RP/BR) smoke obscurant was performed at Pacific Northwest Laboratory. A similar evaluation using white phosphorus (WP) smoke/obscurant is currently proceeding. Future testing with other smokes are planned. The objective of this research program is to characterize the effects of smokes and obscurants on: (1) natural vegetation characteristic of U.S. Army training sites in United States; ...