Content of Cigarette Smoke

• Tobacco smoke contains an astounding 4,000 chemicals, the majority of which have detrimental effects on health, being either poisonous or carcinogenic. These include nicotine, which is the addictive substance, and although there are only small amounts present in tobacco, in larger doses nicotine is lethal. Also present are carbon monoxide, which is found in exhaust fumes; arsenic, which is a highly poisonous substance commonly used in rat poison; and hydrogen cyanide, which was the most common poison used in gas chambers. Formaldehyde is also present and is a carcinogen that is used as embalming fluid.
  
  

Effects of Smoke on Plant Health

• Over an extended period, houseplants exposed to tobacco smoke may eventually be suffocated, as particles found in smoke coat the leaves and stem of the plant, blocking the stoma, which are small pores on the underside of leaves used for gas exchange. In effect, the plant is unable to "breathe." By coating the leaves of the plant, the particles create a layer, or barrier, which reduces plants' ability to photosynthesize effectively. Photosynthesis is the complex process that allow plants to "digest" nutrients. Both photosynthesis and gaseous exchange are vital for plants to grow, flourish and remain healthy.
  
  

Indoor Plants

• NASA studies have found that plants have complex pollution-absorbing capabilities and help to purify and revitalize air. The results of the combined studies of NASA and the Associated Landscape Contractors of America (ALCA) showed that common indoor ornamental plants were so effective at removing pollutants from air, including many of the chemicals in tobacco smoke, that a number of the most effective plants will be launched aboard orbiting space stations as part of the biological life support systems.
  
  

The Study

• Although plants remove substances from the air via the stoma, a study concluded that roots, bacteria in the soil and the leaves are all necessary in air purification. During experiments, activated carbon was placed in the plant pots. The roots of the plants grew into the carbon and degraded the chemicals absorbed from the air by the carbon. The evidence from the initial two-year study by NASA and ALCA provided some very promising and conclusive results, but further research was deemed necessary. Bill Wolverton, a former lead research scientist based at NASA's John C. Stennis Space Center, states, "We feel that future results will provide an even stronger argument that common indoor landscaping plants can be a very effective part of a system used to provide pollution free homes and workplaces." The most effective plants trialed for air purification include philodendron, spathiphyllum, golden pathos and dracaena massangeana.
  
  

Conclusion

• While plants are very useful in air purification and combating airborne pollutants, including those found in cigarette smoke, continued exposure to tobacco smoke can eventually suffocate and kill plants. It is advisable to clean both the upper and undersides of leaves of indoor plants to prevent a barrier of harmful particles building up on the leaves and stem, preventing plants from photosynthesizing. If the leaves and stem are periodically cleaned with a damp cloth, particles are removed, allowing plants to photosynthesize unhindered. Gentle cleaning also unclogs the stoma, meaning that gaseous exchange can take place uninterrupted. If you look after your plants, they will help to look after you.