Can someone point me in the direction of information relating to: "Which earth spere is most affected by pollution?"

I am leaning to atmosphere - due to global warming, but I would like to do more research. Thanks for the help.

Personally, I lean to the biosphere. Look at this:

http://www.cotf.edu/ete/modules/msese/earthsysflr/spheres.html

I suppose it boils down to what you mean as pollution. But if the pollution doesn't affect living things, who cares?