Schools which receive free air-conditioning because they are forced to close their windows to block out noise from Kai Tak could have the privilege withdrawn in July.
The Education Department says it will conduct tests to gauge noise pollution when the airport moves to Chek Lap Kok.
Education officer Yeung King-fai said it was too early to say whether schools would have to return the air-conditioners provided by the department.
He said: 'I think this option is unlikely as it would be costly to clear the air-conditioners and move them to other places. It's not cost effective.
'Another option is to cease existing subsidies to schools.
'But it's still uncertain. We aren't sure if the schools will be free from noise pollution.
'Noise may come from highways and vehicles, not only from aircraft.' Mr Yeung said the department had launched a noise abatement scheme in 1989.
