We hope that these programs will have a positive 'impact on' the community. [=will help the community]
The stress of her job is having a negative 'impact on' her health. [=is harming her health]
We need to be concerned about the environmental 'impacts' of all this construction.
(..) Explorer, this is Houston. - Go ahead, Houston. NORAD reports a Russian satellite has incurred a missile strike. The impact has created a cloud of debris orbiting at twenty thousand miles per hour. Current debris orbit does not overlap with your trajectory. We'll keep you posted on any (..)2013 Gravity