In 2014, Michael Spiteller (Technische Universität Dortmund) and collaborators reported results, also in Angewandte Chemie, that supported the summary that the presence of tramadol in All those tree roots was the result of tramadol acquiring been ingested by individuals and acquiring been administered to cattle (by farmers from the area); https://koningapotheek.nl/product/tramadol-kopen/