tobacco dust in eye dusting The Shaffer sign, also known as “tobacco dust,” is a clinical finding seen An Introduction To Retinal Tears

It gained notoriety for its link to "popcorn lung" (bronchiolitis obliterans) in factory workers exposed to massive amounts of the powdered chemical

Humans have been smoking tobacco and other plants for thousands of years (archaeological evidence from the Great Salt Lake desert pushes tobacco use back over 12,000 years), but cigarettes only entered their heyday in the 20th century, once industrialized agriculture allowed for mass production

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Additional biomarkers of biologically effective dose are (1) protein adducts, in that most carcinogen metabolites that react with DNA also react with proteins, and (2) oxidized damage to DNA bases

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