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 main 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 (FOI) Act, there are still 5,122 kilometres of asbestos cement water mains throughout Ireland.
Some 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 environmental scientist Jack O’Sullivan is calling for the utility to make sure they are in good working order.
"Those asbestos pipes, to my understanding, would be between 50 and 70-years-old - and that's a long age.
"I would say the most important thing Irish Water should do, and should do this quite quickly... is to carry out a risk assessment of the structural integrity of those pipes".
However Irish Water denies asbestos water mains are harmful to people’s health.
It points out the World Health Organisation (WHO) says asbestos can cause cancer if inhaled, but not if ingested through drinking-water.