This was mainly due to the absence of comparability and matching between cases and controls in many studies 31,33,35,36,42
find that counterfeit cigarettes can have as much as seven times the lead of authentic brands, and close to three times as much thallium, a toxic heavy metal.[14] Other sources report finding insect eggs, dead flies, mold, and human feces in counterfeit cigarettes.[15] During prohibition of alcohol in the United States during the 1920s, increased enforcement did not manage to significantly decrease the prevalence of bootlegging because the profit margins were so large, and the distribution networks sophisticated
A different battery from the regular model is an example
So, its clear that the smoking ban back in 2007 had some clear effects on smokers and helped drop numbers as well as put fewer people at risk of health complications