all cigarette brands with pictures What brand of cigarettes you smoke says about you : r/coolguides List of US Cigarette Brands

Hossfeld, Uwe (February 2001)

There were 4,738,256 respondents age 18 and over in the BRFSS from 1996 to 2012 who had complete data for all variables of interest

[151] In Nepal, a health campaign lasting two weeks called "Smokers are not selfish" is started on the occasion of Valentine's Day and Vasant panchami to motivate individuals to quit smoking as a sacrifice for their loved ones and making it a meaningful decision of life

So, it's been shown that even small amounts of activated charcoal even if only in the gas phase of the smoke can absorb a lot of harmful substances

JTIs Ahern had a slightly different take on it, though

Filter length Longer filters can hold more carbon, which may increase adsorption capacity