Wow, thanks for posting this.
Although never formally diagnosed, I have obsessive-compulsive disorder (no need to pay a western doctor to tell me that!) and one of my biggest 'behaviors' is just straight up playing in the dirt. Close friends of
course just think of it as a healthy quirk, kind of cute really.
But this gives me huge insight into why a pile of dirt can stop me in my tracks. And sometimes keep me pre-occupied for hours. I'm probably just re-upping some seratonin that may have gone astray.
Wow, all the crazy info you find on the internet!!
Now, besides just having the craziest knowledge of soil types, I can congratulate myself on knowing well the mycobacterium.
I wonder then if 'that nice soil smell after a summer rain' like when all the bacteria start up again, actually Does increase seratonin levels...?
2
There are friendly bacteria in dirt that increase your serotonin levels. 
