I believe the article stated NOT ALL mummies were exhumed from a tomb but some were simply found buried.
EDIT: yeah read this part, not only is it implied in the statement but also specifically says in soil.
Evidence in mummy hair
To get a better understanding of hallucinogen use in SPA throughout the ages, Niemeyer and his colleague Javier Echeverría analyzed hair samples of 56 mummies from the Late Formative to the Late Intermediate periods of SPA (100 B.C. to A.D. 1450). The mummies, Niemeyer explained, were in good condition,
preserved naturally from the high temperatures, extreme dryness and high soil salinity in the Atacama Desert. Depending on the site,
the mummies were either interred in the ground or entombed in "some sort of stony environment made for them."
Understand: Nature knows no EVIL, Nature knows no GOOD, people know these things, because we perceive these things, with the gift of senses given to us at birth. A good or bad experience is simply a bridge to a another existential time frame, so always live in the moment and make every one a positive moment!
Any and all posts or interactions are to be held as my fictional writings/short stories or dreams. I may even have some delirium setting in, I've never been tested for it. The only exception to this is the statement about nature above, I feel this is a fact!