Some of the variation in weight that is not. accounted for in Tables 1 or 2 is due to the variation. in the wood density of the different species. AdjustÂ­. ment factors have been developed to account for the. variation by species. The adjustment factors were. each species by the average density of all of the trees.
For example, regular smoking increases the risk of developing lung cancer; therefore smoking is a risk factor for lung cancer. The risk factors for mouth cancer include: 1  Smoking - studies indicate that a 40-per-day smoker has a risk five times great than a lifetime non-smoker of developing oral cancer.  Chewing tobacco.
With time, oral cancer may spread firstly to other parts of the mouth, then the head and neck, and eventually to other parts of the body. Mouth cancers typically start in the squamous cells (flat, thin cells) than line the lips and the inside of the mouth-they are referred to as squamous cell carcinomas. Although we know what the risk factors are, experts are not sure what cause the mutations in squamous cells that eventually lead to mouth cancer.