But while these structures can keep draughts out, they also have a hidden threat lurking within.Deep within their crevices and corners, green buildings are susceptible to trapping humid air in which toxic mould can spread.The problem, according to the Health and Safety Executive (HSE), affects between 30 and 50 per cent of new or refurbished buildings.A number of these homes have become ghost buildings after the damp seeped in and destroyed furniture and belongings.The Alberta Court of Appeal in Canada, for instance, has been abandoned since 2001, after renovations to 87-year-old building went wrong.When the renovated building reopened, according to Umair Irfan at ClimateWire, judges and attorneys complained of fatigue, irritated lungs, and watery eyes.‘They couldn't figure out what was wrong,’ Tang Lee, a professor of architecture in the Faculty of Environmental Design at the University of Calgary told Climate Wire.Air quality samples revealed that the problem came from mould growing inside the walls.  The new airtight building trapped moisture breeding toxic mould.Professor Lee said that the situation is a stark reminder that even in pursuit of saving energy, human health should be a major concern in designing and retrofitting the enclosed spaces where people spend most of their lives.‘It's not just making it look pretty, and it's not just making it more efficient,’ she said.The World Health Organisation has termed what has happened in Canada and elsewhere as sick building syndrome (SBS).According to the HSE, the most common symptoms of SBS are headaches, lethargy and poor concentration, skin irritation, dry itchy eyes and a congested nose.Mould is a type of fungus with thousands of types are released at different times of the year. Up to four per cent of the population is thought to react to mould spores - with as many as one in ten people with allergies such as hay fever and eczema affected.Mould spores can also be dangerous for some asthmatics. Around two-thirds of the more serious life-threatening asthma attacks are believed to be triggered by mould.Lyndsey McManus, deputy chief executive of Allergy UK, stresses that mould can grow in centrally heated, double-glazed homes as well as old damp houses and overcrowded flats: 'If the house isn't well ventilated, mould will flourish.'Certain mould species can also cause serious lung infections and damage. Aspergillus, for instance, colonises vegetable matter  and can be found on farms where produce is stored, or in old buildings.The spores can trigger an allergic reaction and, in rare cases, it can damage tissue in the lungs and affect breathing.Mould may also be linked to Parkinson's disease. A recent U.S. study found a compound given off by mould reduced levels of the brain chemical dopamine, a process which causes Parkinson's symptoms, although more research is needed.(dailymail.co.uk)ANN.Az