This can be a tricky question. Plants do NOT purify air. At least not like air purifiers do. Plants do; however, have the ability to slightly lower the amount of certain chemicals in your home. It would take a room filled of thousands of plants in order to purify it. Many thousand, cubic feet of air pass through a house each day, plants only remove a very small part of it. In fact, an average plant removes 13-16 micrograms of PM per square centimeter, which is almost nothing. People breathe in 120,000,000 grams of air each day.