The Question
Eternal
Dry reading, but have a look.
As for nasal snuff tobacco:
Tobacco-Specific Nitrosamines - an overview | ScienceDirect Topics
www.sciencedirect.com
As for nasal snuff tobacco:
Snuff-induced malignancy of the nasal vestibule: a case report - PubMed
The association between nasal snuff and malignancy is not well established. There is epidemiological evidence suggesting that oral tobacco when mixed with lime and betel leaves causes oral cancer in the Indian subcontinent. Similarly, snuff spiced with dried aloe has been reported to cause upper...
pubmed.ncbi.nlm.nih.gov