So with this research in mind, and if you’ve been connecting the dots along with me, please check out the insecticides and fungicides I found when I tested Marlboros and Swisher Sweets, among others. Remember, not one of these have been tested for their impact through inhalation, which is well-known as the most hazardous route of ingestion. Why should they? Nobody ever expected that any human being would be inhaling what you see below hundreds of times a day. Finally, please keep in mind that many of the insecticides and fungicides you see below are designed to work at the molecular level.