Medical coding for nicotine/tobacco uses ICD-10-CM category F17 for nicotine dependence, categorized by product (cigarettes, chewing tobacco, other) and status (uncomplicated, remission, withdrawal)
Concurrent use of both cannabis and tobacco was associated with increased risk (even adjusted for age, asthma, and comorbidities) of respiratory symptoms (OR 2.39, 95% CI 1.583.62) and COPD (OR 2.90, 95% CI 1.535.51) if the lifetime dose of marijuana exceeded 50 marijuana cigarettes
MEDIUM 12 mg - max
While there are at least 60 well-established carcinogens in cigarette smoke, its been known for years that nicotine isnt the direct cause of many of smokings ills
This appears to be a problem found mainly in the US and hasn't been established from E-Cigarette use - in the UK diacetyl is banned as an ingredient for e-liquids, whereas the United States have yet to implement comprehensive regulation for e-liquids