By: Ari Del Tufo Dirt, the reason children are sent to wash their hands and the reason public buildings have hand sanitizer at entrances. Dirt is unclean, unhealthy, and teeming with bacteria. But what of the theory that human beings need bacteria, need dirt? In the early 2000s, English microbiologist Graham Rook began developing the … Continue reading Urban Soil Health and Human-Microbe Symbiosis