Houseplants are well worth the small amount of effort needed to maintain most varieties, offering many benefits besides their considerable ornamental beauty. Adding plants to indoor spaces increases oxygen levels, which freshens indoor air and helps people to breathe easier. Plants absorb our exhaled carbon dioxide and release oxygen through the process of photosynthesis. Houseplants also remove large amounts of toxic substances from the air--including the volatile organic compounds benzene and trichloroethylene--and use microorganisms in the soil to convert VOCs to plant food. They also increase the humidity of the surrounding air by giving off water vapor during photosynthesis and respiration. This reduces the frequency of sore throats and dry skin. The presence of houseplants also positively affects the human psyche, boosting our mood and creativity, and even making us feel better physically. Be sure to get plants that are appropriate for the growing conditions, such as low-light situations.