More than 130 schools in Norfolk still contain asbestos – but a council has confirmed there is no immediate risk to children.
Norfolk County Council has released the names of 136 schools in the county which are known to have asbestos-containing materials, all but one of which - North Walsham High - are primary schools.
But the council confirmed it only held data for schools still maintained by the local authority, not academies - which 164 of the county's 351 primary schools and 46 of its 51 secondary schools now are - or the county's six free schools.
This means it cannot say whether 54pc of schools in Norfolk have the material or not.
In a statement a council spokesman said: "We take the management of asbestos very seriously and it is important to remember that as long as it's left undisturbed and is in a safe condition, asbestos shouldn't be cause for concern.
"Many schools only have small amounts of asbestos identified and often in locations children do not access.
"All our schools have access to professional advice and support regarding the management of asbestos, including guidance and training, and health and safety visits. Where asbestos-containing materials have been identified the school has a register of its exact location and condition. We also undertake specific inspections to evaluate the condition of known materials containing asbestos on a risk basis."
Asbestos was a commonly used building material, including in schools, between the 1950s and 1980s. Its use was outlawed in 1999.
The Health and Safety Executive (HSE) estimates asbestos-related diseases such as asbestosis, mesothelioma and lung cancer kill more than 5,000 people a year.
The National Education Union estimates more than 200 teachers have died of mesothelioma since 2001, while government research published in 2013 found children who are exposed to asbestos are five times more likely to contract the disease than adults aged 30.
But the HSE said the material presented a very low risk to people in school buildings if properly managed.
The Department for Education - which began surveying headteachers about asbestos management in 2016 - advises schools to conduct a survey and assess the risks of asbestos-containing materials, devise a management plan and keep it under review.
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