CHEMICALS. CHEMICALS. CHEMICALS. CHEMICALS. CHEMICALS.
1. Mammal bodies have a myriad of a diversity of types of cells.
2. Specific cells and specific cell types have specific sensitivities and extra sensitivities to specific chemicals and specific chemical compounds--INCLUDING THE 100'S OF CARCINOGENS IN SMOKE--1ST HAND AND 2ND HAND.
THOSE ARE JUST BASIC--ACTUALLY--VERY, VERY, VERY BASIC FACTS.
3. Specific chemical sensitivities of lung cells are rather well documented. DENIAL DOES NOT CHANGE THE FACTS.
4. Delivery of the offending chemicals and chemical compounds to the cell sites can happen via blood AT LEAST.
Sigh.
Perhaps 10% of the cells in your body are actually you. The rest are other creatures along for the ride.