i don't need to tell you because its so big it is very polluted. i would hope not but it is. this answer was made by Finley Dale
It used to be polluted in the London area until about 30 years ago. It is now relatively clean with many different species of fish living in it.
I am afraid I do not know but I don't think it is polluted any more.I do know actually. It's polluted because of all the factories putting their chemicals and horrible stuff into the river and the...
because many turists back then used to sail on boats and this caused more pollution to the river.
Historians are unsure of its original name but the Romans called it Tamesis - and that was nearly 2000 years ago.