Why is a differential wbc count more valuable than a total wbc count when trying to determine?

A differential cound determines the relative percentage of each type of WBC. Increases or decreases in specific WBC populations are often indicative (diagnostic) of specific pathologies.

Smoking damages the respiratory system by inhalation of a foreign substance, that is absorbed and residue is left behind on our lungs sponge like substance. the gas that is inhaled also increase your blood pressure and dilates your blood vessels. also the process of inhaling and exhaling the smoke it causes irritation to the throat and mouth. smoking can cause lung cancer and other respiratory and circulatory diseases. 

Answer(cdc) the leading causes of cancer deaths in males are lung cancer,prostate cancer and colorectal cancer