I think it does matter. It's all a question of balancing risk with reward. For example, a new power source which emits radiation which is deadly after 100 yea

I think it does matter. It's all a question of balancing risk with reward. For example, a new power source which emits radiation which is deadly after 100 years exposure but otherwise reasonably harmless is very different than a similar system which kills off a small percentage of the population at random.