The Daily Star | 11 June 2011

Indoor plants not only look help but also the air to clean fantastic. National Aeronautics and Space Administration (NASA) research demonstrates the efficacy of plants as indoor air cleaners. Indoor plants reduce unhealthy pollutants and airborne bacteria, fungi while adding the humidity needed to combat respiratory and allergic conditions.. Many pollutants are chemical compounds that are released into the air through a process called “off-gassing”. It is often difficult to completely control the indoor climate in an office or home.

Indoor environment
Plants have been proven to remove airborne harmful contaminants. Most people spend the majority of time indoors at home or work. Air conditioning, improved insulation, and energy-saving all reduce air exchange in buildings, so we breathe the same air again and again. Because the modern internal environment is virtually hermetically sealed and the construction materials used, modern synthetic furnishings, computers, electrical equipment, and everyday household products such as cleaning material, can produce harmful substances that are trapped inside the building. These all contribute to the well recognized “sick building syndrome”. Polluted indoor air, contaminated by volatile organic compounds (VOCs), are a major cause of headache, nausea, sore and itchy eyes, loss of concentration and other “sick building” symptoms. The simple addition of interior plants is a natural way to help remove these pollutants significantly. Not only do they put water vapor back into the air, they also absorb heat and filter dust and harmful substances out of the air.
Studies by the NASA prove that plants not only beautify indoor environments, they make them healthier to live in. NASA also studied the benefits of plants for use in future space stations and closed environments. Properly designed indoor planting can provide an inexpensive, refreshingly low-tech means of removing pollutants from the air in offices and homes. Virtually every tropical indoor plant and many flowering plants are powerful removers of indoor air pollutants. It is a scientific fact that the presence of plants keeps people calmer and makes them feel good. Plants encourage a positive work atmosphere, which in turn leads to better performance. Plants also improve the quality of the indoor environment, and consequently the health of the personnel.

Effects of plants on indoor environment
Plants reduce the concentration of carbon dioxide and other substances potentially harmful in high concentrations, such as formaldehyde and benzene. This filtering helps to minimise contaminated air, so leaving indoor air fresher. Plants also increase the “thermal comfort” as they help to cool down the office area through evaporation and by providing shade.
Plants and associated soil micro flora can be used as effective air filters which remove and absorb toxic Volatile Organic Components (VOCs) from indoor air. It is possible to improve indoor air quality by using a specially screened plant combination which efficiently removes toxic compounds from ambient air. Plants can provide an effective way of decreasing mycotoxins concentration in indoor air by destroying bacteria and fungi. Begonia and geranium were shown to decrease air microorganism content by 43%, small flowerish chrysanthemum by 66%. Numerous studies have shown that looking at plants and other natural elements reduces stress levels. It has also emerged that a view of greenery stimulates the recovery of hospital patients. Some benefits of indoor plants are: Absorption of carbon dioxide and emission of oxygen refreshing the air, absorbing harmful substances and filtering out dirt and dust from the air, keeping the atmospheric humidity levels up, providing a cooling effect, reducing stress levels, lifting the general mood, encouraging better performance, increased positive feelings and reduced feelings of anxiety, anger and sadness, faster recovery from mental tiredness, reduction of sound levels, reduction of absenteeism at the workplace, improved image — interiors are perceived as more expensive.

Effective Use of Plants
Different types of plants have different positive characteristics. Some purify and some humidify the air. Below is a chart of the plants that most effectively removed pollutants from the air in the NASA study:
Where and how to place
When positioning plants, be strict in a balance between light and ventilation because the effect of plants on indoor air pollution appears to be reduced if they are set in a draft. One plant should be allowed for approximately 10 square yards of floor space, assuming average ceiling heights of 8 to 9 feet. This means that we need two or three plants to contribute to good air quality in the average domestic living room of about 20 to 25 square yards. The more vigorously they grow the better job they’ll do for you. Keep the air moist by misting plants. Avoid locations in the rooms where there are drafts or sudden temperature changes. Pollutants are absorbed through the leaves, so keep the leaves clear of dust by wiping gently with a damp cloth.

Conclusion
In future, we will be cleaning up environmental pollution with plants. Right now, add houseplants to each room to clean the air you and your family breathe.