When articles like this come out it's important to exercise a bit of healthy scepticism and look at whether this study was funded by interested corporations. This does happen, and sometimes through non-profits that are themselves fronts for corporations. See this excellent article by George Monbiot from a while back: <a href="http://www.monbiot.com/2006/02/07/smoke-rings/" rel="nofollow">http://www.monbiot.com/2006/02/07/smoke-rings/</a>