Wow what a great question!
Let’s start by talking about healthy lungs. Do you know what colour healthy lungs are? Healthy lungs are a pretty Pink. So it is very interesting to understand why lungs change from Pink to Black. This change happens slowly over many years of smoking and is caused by the chemicals inside Cigarettes.
One single puff of cigarette smoke has thousands of chemicals. When someone breathes this in all these chemical go straight into their lungs. Some of these chemicals are toxins which means they are harmful to the body. One of these toxins is called sticky tar. This sticky tar is black in colour and after years of smoking it builds up inside the lungs and causes them to become black too. Also, the lungs recognise the toxins and send immune cells to fight them. This fighting between our cells and the toxins causes something called inflammation which means swelling. If the person keeps smoking for more years the inflammation will become scar tissue which is dark and stiff compared to healthy lungs.
Did you know people that worked with coal also had their lungs turn from Pink to Black. This is because they would breathe in the black coal dust and over many years more and more accumulates in their lungs and their lungs become blacker.