Numerous studies conducted by the EPA (Environmental Protection Agency) over the last 25 years have shown measurable levels of over 107 known carcinogens in modern offices and homes. The presence of these VOC's (volitile organic compounds) is due to the switch from open windows to energy efficient living and working environments, made necessary in the 1970's due to the energy crisis atmosphere that had developed. Combined with the advent of modern building methodology and products, the result has been energy efficient homes and offices that contain amounts of known cancer causing chemicals. In extreme cases, some buildings have such high levels of contaminants that they are known as "Sick Buildings" because exposure to them results in multiple symptoms of sickness exhibited by the inhabitants who try to use them.
The fact that concerns most scientist and doctors is the unknown effects that could occur in humans over long periods of time, being in contact with low dosages of these cancer causing VOC's such as are found in modern offices and homes. Scientists say it is still too soon to tell whether increased incidences of cancer can be attributed to exposure to modern living and working stations.The NASA research suggest that by including indoor house and office plants, one may reduce substantally the amount of exposure to now common VOC's one experiences daily routine. On going research indicates that lessening prolonged exposure to VOC's and other commonly found indoor polutants (secondhand smoke, ozone, etc.) can substantilly to your long term quality of life.
In summary, the NASA research combined with increasing large amount of corroborating research indicates that it is beneficial to have live plants in modern office and home environments. Plants and the accompanying benefits they bring, can help to improve indoor air quality in any building. Combined with increased ventalation rates and other recommended remedies, plants even help clean up 'Sick Buildings".