From the article: "If the elements in the soil and water of a region work their way into the plants grown there, they also work their way into our bodies when we eat the produce of those plants, or when we eat the meat of animals fed on those plants. We ingest these elements, process them, and use them to build flesh, teeth and bones. So the elements making up our bodies can tell us something about the food we’ve eaten and the land that supports us."

Seems like the same idea would apply to regional differences in health including mental health. An obvious one would be if the land is high in lead, the people living on it might be more violent. Areas with oil wells are likely affecting air and food quality. Maybe areas with a lot of lithium result in happier people. Western medicine has largely ignored environmental effects. A map of background radiation levels across the world might have an interesting health story to tell as could multi-spectral satellite imagery. Oritain might be sitting on a wealth of very useful health data, unaware of it.