An Israeli team has found more clues to the life of prehistoric man in a set of 400,000 year old teeth.

In addition to learning more about their carnivore habits, however, the Tel Aviv University researchers have found evidence of man-made pollution dating back hundreds of thousands of years.

The teeth were found in a cave outside of Tel Aviv in 2011. Their calculus (more commonly known as tartar) has provided a wealth of information about prehistoric life.

Professor Avi Gopher of TAU also explained the prehistoric dental exam was the first of its kind.

“Human teeth of this age have never been studied before for dental calculus, and we had very low expectations because of the age of the plaque,” Prof. Gopher said. “However, our international collaborators, using a combination of methods, found many materials entrapped within the calculus. Because the cave was sealed for 200,000 years, everything, including the teeth and its calculus, were preserved exceedingly well.”

Among the findings, researchers discovered that prehistoric humans diet contained some plants and they even brushed their teeth with a non-edible fiber found on one of the teeth.

The teeth also revealed that their use of fire came at an environmental and health cost.

“This is the first evidence that the world’s first indoor BBQs had health-related consequences,” TAU researcher Ran Barkai said. “The people who lived in Qesem not only enjoyed the benefits of fire — roasting their meat indoors — but they also had to find a way of controlling the fire — of living with it.”

He added that finding signs of respiratory irritating charcoal in the tartar is an important discovery.

“This is one of the first, if not the first, cases of man-made pollution on the planet,” Barkai said.