Residents of more than 70 homes in Co Louth have been warned not to drink tap water due to dangerous lead contamination, it was revealed today.
Eighteen houses in Dundalk and two in Ardee tested positive for the potentially lethal metal, with one reading more than six times the recommended safe limit.
However, a spokesman for Louth County Council said as many as 70 properties which share the contaminated water pipes could be affected.
"The latest results show a total of 18 properties with exceedances in the the maximum limit for lead in water after flushing was carried out," said director of services Eamonn Walsh.
"However, there are in fact approximately 70 properties in total sharing the lead service pipes causing the problem."
One house in Dundalk measured 153 micrograms of lead per litre while a handful of other homes were almost four times over the recommended safe limit of 25 micrograms.
The latest tests were carried out on foot of a Health Service Executive order issued after increased lead levels were detected two weeks ago.
The council said it expected to get results of further tests before the end of the week.
Officials will continue to take samples from the water system and are also planning to check the local water treatment plant.
"Based on the results of further samples, where deemed necessary, Louth Local Authorities will also be replacing lead service pipes in public areas and local authority housing," Mr Walsh said.
The council will provide free bottled water to affected homes and has established a helpline for concerned residents.
More than 150 houses in Galway were warned not to drink tap water last month after 12 homes tested positive for lead contamination.
Over-exposure to lead can damage the nervous and reproductive systems and kidneys and can cause high blood pressure and anaemia.
It is also harmful to the developing brains of babies and to young children, and consequences may include learning disabilities and behavioural problems.
At very high levels, lead can cause convulsions, coma and death, according to the World Health Organisation.
PA