Revitalize indoor air with houseplants. Levels of ozone, a low-grade aire pollutant, accumulates in houses closed up in winter. Ozone triggers fatique. Get some houseplants! Their green leaves soak up ozone, improving air quality and your energy level in just two weeks. For some extra fresh air, crack your window open just a bit and enjoy the fresh breezes. This cuts ozone levels by half according to researcher Paula Balillie-Hamilton, M.D.