The widower of a retired art teacher who died of asbestos-related lung cancer says it is suspected she was exposed to asbestos at school.
Renee Eden worked in three different Flintshire schools
A coroner is writing to Flintshire Council over possible dangers after the death of Renee Blodwen Eden, 69, who worked at three schools in the county.
Allan Eden, of Llangoed, Anglesey, whose wife died last year, fears more teachers and pupils could be at risk.
The council said it constantly monitored the safety of its buildings.
Thursday's inquest recorded a verdict that Mrs Eden, a mother-of-four, died from mesothelioma, due to exposure to asbestos.
She taught art at Castell Alun, Argoed and Elfed schools before she retired in 1998.
Mr Eden said nobody knew for certain how his wife came into contact with the asbestos which led to her fatal condition, but it is suspected it would have been something she was exposed to while working at one of the schools.
Mr Eden said Dewi Prichard Jones, the north west Wales coroner, said he would be writing to the council about the possible dangers and the need for further action.
A council spokesman said it could not make any further statement until it understood directly from the coroner the details of the inquest.
"The council is making direct contact with the coroner today to obtain these," said the spokesman on Friday.
"Like all public bodies, Flintshire County Council is under stringent legal health and safety requirements and is constantly monitoring and managing the safety of its buildings."
Mr Eden said he and his family contacted the authority before his wife's death to highlight the issue.
They have been shown surveys of Flintshire buildings carried out by the authority to assess any potential risk.
But Mr Eden said fibres could lay dormant in a person's lungs for decades before they develop the disease.
"It's like an iceberg. All they're (hospital consultants) seeing at the moment is the tip and by 2015 there could be considerably more deaths."
Mr Eden said he was not sure what more local authorities could do to tackle a problem which went back so long.
But he added, "I don't whether the people who are looking after buildings are sufficiently aware of the dangers. They know that it's dangerous, but are not aware of how dangerous."
Mr Eden said their daughter Kate, of Kingston upon Thames, Surrey, who works in the health industry, had been more involved than himself in trying to raise awareness of the issue.