black gums from chewing tobacco #DYK? Smokeless tobacco products cause cancer of the mouth, esophagus, and Dark Gums Vs Healthy Gums:

SAMHSAs Synar Program and FDA tobacco retail compliance inspection contracts work together in a strategic partnership focused on compliance inspections to reach the shared goal of reducing youth access to and use of tobacco products

Generally no

It's a common concern, especially if you're trying to be discreet or if you're living with non-smokers

Like secondhand tobacco smoke, it contains highly carcinogenic compounds, heavy metals, hydrogen cyanide (used in chemical weapons), butane (used in lighter fluid), toluene (used in paint thinners), arsenic, lead, and even radioactive Polonium-210 (used to murder a Russian spy)