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.
Occasionally, tongue disorders are caused by the emergence of cancer in the mouth. Tongue cancer can have genetic links or be related to long-term tobacco and alcohol use, among other causes.