A method of purifying air polluted by smoke and fumes, such as from wildfires and other hazard, may deploy a series of fluid filled vessels that act as filters to trap and/or neutralize components that would foul an aqueous suspension of gold nanoparticles that is effective in converting toxic carbon monoxide to carbon dioxide. Non-toxic fluids may be used. As the gold nanoparticles are effective in a basic solution, the solution may contain a visible pH indicator or an apparatus that deploys the method may continuously monitor the pH thereof.