How can i reduce this second hand smoke?

WHAT 2nd hand smoke?: Don't know what you mean by "this." easiest answer is don't hang around in the same places as smokers. If it is your house, don't allow smoking. If you can't achieve that, keep doors closed and stay in separate rooms. There are commercially available "smoke-eaters" which vary in effectiveness in removing smoke - they are similar to air conditioners, and must usually be vented.