How lack of regulation for tattoo ink puts Americans at risk

Nearly one in three Americans surveyed this summer said they have at least one tattoo, according to the Pew Research Center. But while tattoo artists are required to have a license in all 50 states and the District of Columbia, tattoo ink is totally unregulated in the United States. Dr. Thomas Rohrer, a dermatologic surgeon, joins John Yang to discuss the associated health risks.