|MadSci Network: Botany
You need to be more specific about what plant you are interested in. Some plants do well in a polluted atmosphere while others do not. The ginkgo tree thrives in areas where there is much pollution. I would imagine that the particles in cigarette smoke might clog up the stomatal pores on a leaf causing less gas exchange and affecting photosynthesis. However, if there is an increase in carbon dioxide from the cigarette smoke, photosynthesis could increase. You might check out the Wisconsin Fast Plant web page for experiments to measure the effects of cigarette smoke on plants.
Try the links in the MadSci Library for more information on Botany.