There are more than 5,100 kilometres of asbestos water pipes in Ireland.
The substance can cause cancer if inhaled, but Irish Water denies that is the case if you consume it through drinking-water.
Asbestos cement was commonly used to build truck mains from the 1950s to the 1980s, but it has not been used for that purpose in Ireland since that period.
But according to details released under the Freedom of Information, there are still 5,122 kilometres of asbestos cement water mains throughout Ireland.
22% of it is in Cork, which is nearly double the amount in greater Dublin.
Other counties with significant amounts are Donegal, Tipperary and Kerry.
Irish Water was unable to say how many of the pipes had burst in recent years.
But Jack O’Sullivan, an environmental scientist, is calling for the utility to make sure they are in good order.
“Those asbestos pipes, to my understanding, would be between 50 and 70 years old,” he said.
“And that’s a long age.”
Mr O’Sullivan said that the “most important thing” Irish Water should do is to “carry out a risk assessment of the structural integrity of those pipes”.
But Irish Water denies asbestos water mains are harmful to people’s health.
It points out the World Health Organisation says asbestos can cause cancer if inhaled – but not if ingested through drinking-water.