Does Having Plants in a House Raise the O2 Levels?

Photosynthesis

• Plants add oxygen to the air during a process called photosynthesis. They contain chlorophyll, a green pigment that absorbs energy from sunlight. During this process, a plant absorbs water through its roots and carbon dioxide through its leaves. Water molecules contain hydrogen and oxygen atoms. The light causes a reaction in which the water molecules split. This split creates energy for the plant from the hydrogen atoms and sends the remaining oxygen atoms into the air.

Light

• Plants produce oxygen if light levels are suitable for that particular plant. Some require low or medium light while other plants need full sun exposure. Houseplants that thrive in dark corners include Red Emerald philodendron, a vining plant that requires support for climbing. Rubber plants, which have thick, glossy leaves, grow best in medium light a few feet from a sunny window. Other plants, such as the treelike weeping fig, grow best in a sunny window.

Pollutants

• Some houseplants remove pollutants from indoor air as they add oxygen. In a 1993 article published in the Journal of the Mississippi Academy of Sciences, B.D. Wolverton and John D. Wolverton wrote that their study showed that certain plants remove particular pollutants better than others. For example, the Boston fern removes formaldehyde and Lady palm removes ammonia more effectively than other plants. The leaves of these plants absorb toxic chemicals from the air and move them to the roots. The roots produce a substance that promotes microorganism growth and these microorganisms clean the air by breaking down toxic chemicals.

Considerations

• According to the Lady Bird Johnson Wildflower Center, a houseplant that receives insufficient light will produce carbon dioxide instead of oxygen. In a process called respiration, a plant uses oxygen to break down stored carbohydrates for energy and then emits carbon dioxide into the air. On the other hand, excessive light exposure can damage pigments in philodendrons and other shade-loving plants. The plants are then unable to produce oxygen.