Washing or rinsing the tea leaves

Here is a nice introductory video by China Life (a vendor) on why people rinse teas, the different reasons (essentially the same as in the Teasenz article, but video presentation is nice, and content varies a little):

https://youtu.be/i28odG-O5us?list=PLAtdGF0-xVNbPbgkt9hh4hMnqji0RUNMK

It’s hard to get any feel for what types of impurities or toxins really could be present in tea, but this article talks about measuring those related to shou pu’er and aged sheng pu’er, which probably really should be rinsed. It also goes into which microbes are fermenting pu’er tea, fascinating stuff, if a little dry (the toxins / rinse part is close to the end):

http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0157847