The humble latrine, or flush toilet, reduces disease by twice as much as just putting in clean water.
I'd grown up thinking that a [sanitary toilet] was my right, when in fact it's a privilege - 2.5 billion people worldwide have no adequate toilet.
In practice, the ocean is the world's wildest place because of both its fearsome natural danger and how easy it is out there to slip from the boundaries of law and civilization that seem so firm ashore.