And then there's this from Greenpeace:
Then we got the results from the lab. Arsenic, mercury, lead, selenium... a neurotoxic and cancer-causing cocktail. The results are not pretty, and reveal clues to the reasons behind China’s lung cancer epidemic. The WHO recently released the results of a massive research project into what is making us sick, pointing out air pollution as the biggest environmental health risk in the world. The research estimated that 20% of lung cancer cases in China are caused by outdoor air pollution.
Zhong Yu, a marathon runner, is one of the volunteers who had her personal air pollution exposure tested. She was shocked to find out that her samples contained arsenic levels exceeding the national standard X-fold: ”No matter how good the training shoes you have, how nice the clothes you have, how good the coach you can hire; but without good air, and running with a mask, the meaning of running is gone.”