How to Grow Planet a new programme on BBC2 - Starts on 7 February at 9pm In this series Professor Iain Stewart tells a stunning new story about our planet. He reveals how the greatest changes to the Earth have been driven, above all, by plants. In this first episode Iain journeys from the spectacular caves of Vietnam to the remote deserts of Africa. He sees how plants first harnessed light from the sun and created our life-giving atmosphere. He uncovers the epic battle between the dinosaurs and the tallest trees on the planet. And, using remarkable imagery, he shows plants breathing - and for the first time talking to each other http://www.bbc.co.uk/programmes/b01bywvr

Please havea look at the article in Medical News: Rehab Patients Report Increased Well-Being When Interior Plants Introduced http://www.medicalnewstoday.com/articles/212725.php

Clem thanks for the link. Was this article published recently - I couldn't find a date on the weblink? The NASA original study was more than 20 years ago and whilst valid and a starting point for much other research, in many ways has been superceded. Dr Ronald Wood (Univesity of Technology in sydney) conducted further studies looking at plant air cleaning, one in closed chambers and one in situ in offices. He found in the first avenue of research that plants and their growing medium absorbed the toxins and the microbes in the soil turned them into food for the plant; they were never satiated and speeded up their intake the more toxins they were fed. In the second in situ test, Wood quantified how many plantswere needed to clean the air in a single occupancy room of 12m squared. Fjeld (University of Agriculture in Oslo, Norway) found that plants cleaned the air in classrooms, offices and an xray department. These research studies were completed more than 10 years ago. Smith (John Moores University, Liverpool) carried out in situ research in Scotland (2008-9) and found that the air in an open plan office was cleaner with the plants. So I feel that there is a growing body of research which has helped to confirm Wolverton's early studies with some consideration for how to facilitate this. <p> Of course, one of the bigger stories if you like is that plants do more than clean the air! They have a very positive effect on our health and wellbeing, not to mention our attitude, motivation and performance.

Here's an interesting take on the science of "plants-for-clean-air" studies from the journal "Practical Asthma Review" in the US: http://www.practicalasthma.net/pages/topics/aaplants.htm Any thoughts? This obviously flies in the face of the current conventional wisdom in the trade on this topic, but the author and the researchers present a compelling argument nonetheless.

Plants makes more satisfied with our jobs! Dr Tina Marie Cade, Associate Professor of Horticulture in the Department of Agriculture at Texas State University, conducted an online survey amongst office workers in Texas and the Midwest. The survey included questions about job satisfaction, physical work environments, the presence or absence of live interior plants and also windows, environmental preferences of the office workers, and demographic information. Survey data showed significant differences in workers' perceptions of overall life quality, overall perceptions of job satisfaction, and in the job satisfaction subcategories of ‘nature of work’, ‘supervision’, and ‘co-workers’ among employees who worked in offices with plants or window views compared to employees without one or both. Findings indicated that people who worked in offices with plants and windows reported that they felt better about their job and the work they performed. Employees who worked in offices with plants rated their job satisfaction higher than those in offices with no plants and also the statements relating to bosses, colleagues and their overall outlook of those in planted offices were more positive. Overall those in the planted offices were happier and had a more positive outlook on life generally. According to Cade, "There were no statistically significant differences among the categories of age, ethnicity, salary, education levels and position among employees who worked in offices with or without plants or window views. Source: American Society for Horticultural Science (2008, May 19). Greener Offices Make Happier Employees. ScienceDaily.

Laura has been busy discussing the health benefits of plants in the Horticulture Group at Linkedin. Here's my contribution in response to the discussion about the NASA research: "Dr Bill Wolverton condusted this research for NASA after a space craft returned to earth with more than 300 toxins in the air inside the capsule. His research has been much quoted and his research inspired Dr Ronald Wood (UIniversity of Sydney, Australia) to look into how plants absorb toxins, how they never get satiated and to make some initial calculations about how many plants are needed. Dr Wolverton also conducted research which showed that Succlents, Bromeliads and some orchids do their absorption and exchanges i.e. emitting oxygen at night. This means that these type of plants are good in bedrooms as they refresh the air whilst we sleep." Posted by Coll Smith

Has everyone seen the first more indepth articles on the site about plants and how they clean the air? Check the links on the Benefits of Plants pages .....