The council has responded after independent asbestos researchers, Michael and Richard Lees, of Ellingham, Northumberland, have led a long-standing campaign for more thorough asbestos checks to be carried out in school buildings across the country, following the death of Michael's wife, Gina Lees, a nursery school teacher, to mesothelioma.

Mrs Lees contracted mesothelioma, a cancer related to asbestos exposure, through inhaling the substance when putting drawing pins in the walls of her classroom to pin up children's pictures.

Michael and Richard have set up their own website in an attempt to educate people across the UK about the dangers of even small amounts of asbestos. They work alongside scientists dedicated to researching the material and also refer people who contact them for advice to relevant experts.

Richard said school buildings that usually contain the most asbestos are 'system built' schools, built under the CLASP (Consortium of Local Authorities Special Programme) scheme between 1945 and 1980.

He added: "These in particular must carry out reassurance testing and have an asbestos management plan in place if the substance is found.

"Asbestos can be released into the air easily in a school environment, due to doors slamming and sitting on surfaces containing asbestos, such as windowsills.

"We now aim to educate schools about the dangers and ensure careful checks are carried out. Michael often holds lectures around the country with MPs and the Health and Safety Executive to raise awareness of the issue."

However, Flintshire Council have assured residents that all school buildings in the county are safe.

A spokesman said: "We do not have any CLASP buildings within Flintshire. However, as a result of ongoing remedial works, we have determined that the essential feature of system buildings, a lightweight steel frame requiring asbestos board fire protection, is not evident, although we have found materials containing asbestos in overcladding covering internal drainage downspouts.

"Asbestos surveys commenced in schools, carried out by UKAS laboratory accredited consultants, in 2002, on a rolling programme and re-inspection surveys are carried out periodically.

"One high school was considered as a system design building and was subject to inspection and air monitoring in summer 2007 by a UKAS accredited consultant, who found that although some low priority remedial work was identified, the results were satisfactory."