The dangers of sawdust (micro wood?) vary from species of tree to tree, but are generally well known and studied. in particular Manchineel and Yew are known to be dangerous.

Wood in its natural state is not a safe substance. African Mahogany for example is highly toxic, causing dermatitis, respiratory issues, giddiness, vomiting, boils, asthma, headaches, and nosebleeds. Has also been linked to nasal cancer.

https://www.mountainwoodworker.com/articles/toxic_woods.pdf