400,000-year-old dental tartar provides earliest evidence of manmade pollution

Most dentists recommend a proper teeth cleaning every six months to prevent, among other things, the implacable buildup of calculus or tartar -- hardened dental plaque. Routine calculus buildup can only be removed through the use of ultrasonic tools or dental hand instruments. But what of 400,000-year-old dental tartar?

Tel Aviv University researchers, in collaboration with scholars from Spain, the U.K. and Australia, have uncovered evidence of food and potential respiratory irritants entrapped in the dental calculus of 400,000-year-old teeth at Qesem Cave near Tel Aviv, the site of many major discoveries from the late Lower Paleolithic period. 

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