Hundreds of schools in Sussex still contain asbestos.
The latest figures come amid calls from experts, MPs and unions for more to be done to limit potential exposure to pupils and teachers.
Only two schools in Brighton and Hove definitely do not contain asbestos, while council officials say 178 of 191 schools in East Sussex are “assumed” to contain the substance.
Brighton and Hove City Council said no “high risk” asbestos has currently been identified in its schools.
It said it follows Health and Safety Executive advice that if asbestos is sealed and not disturbed then it is safe.
But campaigners are calling for even greater regulation of asbestos in schools and say deadly fibres can be released simply by putting pins in walls or slamming doors.
They also said that asbestos-related teacher deaths are on the rise.
Asbestos is the greatest cause of work-related deaths in the UK. When fibres are inhaled it can cause cancers including mesothelioma.
Michael Lees, of campaign group Asbestos in Schools, said all types of asbestos can cause cancer but amosite – found in many system-built schools erected from the 1950s onwards – is particularly dangerous.
West Sussex has 77 such schools.
The material was used to fire proof structural columns and is also found in skirting boards, ceilings and walls.
East Sussex County Council and Brighton and Hove City Council said they carried out rigorous checks to ensure asbestos was not posing a risk and removed any deemed unsafe.
St Andrew’s and Downs View Link College are the only schools in Brighton and Hove where there is definitely no asbestos.
Education Minister Nick Gibb, MP for Bognor Regis and Littlehampton, said the HSE advised that it was safer to leave asbestos that remains in buildings undisturbed rather than try to remove it.