Cadmium

Its deadly dual purpose? It's used in batteries since it's a toxic, heavy metal! It's produced as a by-product of smelting metal ores and it is present in exceptionally high levels in cigarette smoke. In fact, smokers have twice as much cadmium in their blood than non-smokers just by virtue of their bad habit. 

Approximately 40 to 60 percent of the cadmium inhaled while smoking is able to pass through the lungs and body. That's a terrifying statistic, and hopefully, this will be enough to get you to quit, or at least seriously consider quitting smoking.