Some British schools are not meeting a legal duty to protect their pupils from potentially deadly asbestos, according to new research.
Atac chairman John O'Sullivan said: "Numerous incidents have taken place where asbestos fibres have been released, the schools contaminated and teachers, support staff and pupils have been exposed.
"The increasing numbers of mesothelioma deaths amongst teachers and support staff is testament that the policy of management has failed."
Government policy is for schools to leave asbestos undisturbed. The substance should be managed rather than removed, it advises.
But many schools lack the resources to manage it safely, according to Atac. It said asbestos had been damaged in more than half of the schools it visited for this study – which is when the substance can become dangerous.
About 75% of Britain's schools are thought to contain asbestos and 178 teachers are known to have died from asbestos-related illnesses, says the report.
In 2009, a questionnaire concerning asbestos management was sent out to schools by the Department for Children, Schools and Families and the Health and Safety Executive. As a result, 34 local authorities are now being investigated by the HSE.
The main teaching unions are calling for a widespread audit of asbestos danger in schools.