Also install carbon monoxide detectors near sleeping areas and on every level of the home. Air Cleaners Trees are important in the landscape for many reasons, but one is because they are nature's air conditioners and air filters. A large tree may have 200,000 to 400,000 leaves, which act like a continuous air filter. An acre of trees may remove as much as 13 tons of dust each year. Streets with trees have 3,000 particles per liter of air, compared with 10,000 to 12,000 in streets without trees.
Trees also remove heavy metals.
Trees serve as moderate filters of some gaseous pollutants such as sulfur dioxide and carbon monoxide.