There are a lot of potential candidates... too many to be honest, and a lot of them are related to basic economic activities. History shows that environmental i

There are a lot of potential candidates... too many to be honest, and a lot of them are related to basic economic activities. History shows that environmental issues driven by economics aren't solved until an alternative comes along and is adopted; the problems of dead horses and horse dung in NYC streets were solved by... the automobile. I'm put in mind of the recent paper posted on HN regarding magnetic nanoparticles being found in human brains. Unrelated to autism (probably) is the increasing study of prions and in general, maladaptive protein synthesis. What isn't known about these issues could fill volumes.