Further studies were carried out by NASA involving the 'Biohome', a small, tightly sealed structure with an interior constructed of plastic and other synthetic materials. The emission of many VOCs was anticipated and people entering the Biohome experienced typical symptoms associated with sick building syndrome, such as breathing problems and burning eyes and throat. Air samples were taken before and after the addition of indoor plants and the results showed a substantial reduction of VOCs. Unsurprisingly, the individuals who entered the Biohome no longer experienced symptoms associated with sick building syndrome. This study provided proof that plants can become an integral component in maintaining healthy air inside hermetically sealed buildings.    ......more