Tobacco smoke contains heavy metals, smoking rises lead levels. https://www.researchgate.net/publication/322790056_Blood_Lead_Levels_among_Cigarette_Smokers htt

Tobacco smoke contains heavy metals, smoking rises lead levels. https://www.researchgate.net/publication/322790056_Blood_Lead_Levels_among_Cigarette_Smokers https://www.researchgate.net/publication/322790056_Blood_Lea... 11 out of the 76 short term exposed workers had myopia, while 10 out of 124 long term exposed workers had myopia, which is much less.