Why getting your hands dirty is good for you

A growing body of research suggests that contact with soil, plants, and other natural materials can boost the diversity of microbes on our skin, which in turn may benefit our immune system. Studies in Finland, including experiments where people rubbed soil on their hands and children played in forest-floor daycare yards, show increases in skin microbial diversity and changes in immune markers. Even brief contact can have effects, but regular or prolonged exposure may be needed for lasting benefits.