Human environment interaction are essentially the ways in which humans affect their environment and how they are affected by their environment. In Italy examples of this could be Italians who fish the Mediterranean coastal waters. Other examples could be Italians who farm or Italian factories which release pollutants into the environment. Any number of events could count as human environment interactions.
The oldest of the zircons in the study, which came from the Jack Hills of Western Australia, were around 4.3 billion years old—which means these nearly indestructible minerals formed when the Earth itself was in its infancy, only roughly 200 million years old.