On July 6, 2005, the Chinese media outlet Beijing Youth reported that the First Qin Emperor's mausoleum would become a coal mine in a hundred years. The expert source for the report was Dr. Cao Junji, an assistant researcher at the Institute of Earth Environment, a branch of the Chinese Academy of Science.
According to Dr. Cao, the world famous terra-cotta warriors and horses in the First Qin Emperor mausoleum in Xi'an are slowly deteriorating because of severe air pollution. Ever since these antique terra-cotta figures were discovered after being buried underground for over 2,000 years, they have faced the threat of oxidation and water invasion. If the situation continues, it is predicted that eventually the noses and hairstyles of these figures will be eroded and the arms will fall off the statues.
Dr. Cao also stated that if no protection measures are taken, the Emperor's mausoleum will become a coal mine in a hundred years. In 1987, these figures, built by the First Qin Emperor, were listed as the eighth wonder of the world in the UNESCO World Heritage List. If the prediction is true, it would be a tremendous loss to the Chinese people. The Chinese government may face strong social pressure if these valuable relics are lost because of poor management.
Dr. Cao is currently working on a research project with the Emperor Qin's Terra-cotta Warriors and Horses Museum called "Characterization of the Air Pollution in the Museum." This two-year project started March 3, 2005.
According to the report, a researcher placed a piece of bright clean white paper in the Museum and found it had become dark gray and covered with carbon particles after 24 hours. The source of the carbon particles, according to a well-known air quality expert, is suspected to come from the tourists' breath and the ammonium chemicals from their clothes. The pollution is thought to have come from the buildup of over two million visitors per year.
Besides air pollution, the terra-cotta warriors and horses are being slowly degraded by mold. These figures were at one time contaminated with over 40 types of fungus. Over 1,400 of the warriors and horses are presently contaminated with fungus.