I don't know how anyone can answer this without citing every site report in existence to simply answer "no".

That being said, apparently there are abnormally high levels of mercury around the tomb of Qin Shi Huang. It's said that within his tomb is a scale model of the empire with rivers done in mercury with crossbows primed to attack anyone daring to enter. No one has opened the tomb just get due to concerns for health and current preservation techniques. With Qin Shi Huang being China's first emperor and all, it is important to gather as much information as you can when excavating.