I just accidently ran across this article where several experts discuss pollution in mainland China and its affect on tea. Comments are included by Sebastien of Jing Tea Shop and Stephane of Tea Masters.
http://chadao.blogspot.com/2007/08/all- ... luted.html
Re: How Pollution in China Affects Tea
"I wouldn't worry about the quality of Chinese tea, as long as I control what goes into my mouth."