Levels of cancer-causing pollutants at former Limerick Gasworks site above safety limits

Long-term exposure to benzene has been linked to leukaemia

Levels of a cancer-causing pollutant above recommended safety limits were recorded at several locations in the vicinity of the former Limerick Gasworks site over the past year, according to the State’s environmental watchdog.

The Environmental Protection Agency has revealed that the elevated concentrations of benzene — a known carcinogenic — were logged in ambient air readings from active and passive monitors between February and October during a major remediation project on the site.

The EPA noted that the highest levels of benzene — almost five times the recommended limit — occurred during the transportation of heavily contaminated material from the former gasworks which are located at Dock Road in Limerick.

Around 3,500 tonnes of contaminated material was loaded onto a ship at Limerick Docks for export to Finland for treatment.

However, the EPA pointed out that the safety limits are based on exposure at such levels for a period of 12 months or more.

Long-term exposure to benzene is known to cause cancer in humans such as leukaemia.

The EPA said low concentrations of various organic compounds including benzene had been recorded since September after all activity on the site had ceased.

It said lower levels were also found during a period between March and June when work on the site was suspended under the Covid-19 pandemic restrictions.

The watchdog said the testing was carried out in order to provide information on air quality in the area following numerous complaints from local residents about emissions during the remediation works.

People living in the area reported problems with odour, noise, and dust from the former gasworks facility.

Coal gas manufacturing, which had taken place at the site from the 1830s up to 1974, resulted in the production of hazardous materials such as coal tar, which was stored in underground tanks.

However, the coal tar leaked into the ground over many decades, contaminating soils and ground water at the site.

The EPA said it was established some potentially odorous hydrocarbons like benzene were released during the excavation of soil as part of the remediation works.

A condition of the licence held by Gas Networks Ireland for the remediation project was that no emissions including odours would interfere with amenities or the environment beyond the boundary of the former gasworks.

The EPA stressed that the air quality standard (AQS) for benzene was set for long term exposure — 12 months.

“A complete assessment would require continuous monitoring during a full year. That was not the purpose of this exercise since the activities on the site were expected to be completed in a few months.

Therefore the results of this investigation should be taken as an indication of a potential AQS breach had the activity extended to a full year. 

The EPA said the results showed activities carried out on the site had contributed to the elevated levels of pollutants in the air.

“It is evidence that once the activities ceased on site, the benzene concentrations returned to background levels,” the EPA said.

The remediation works on the Dock Road site was recently honoured with a prestigious Brownfield Award for the best international remediation project.

The works, which were overseen by Gas Networks Ireland, involved the removal of 80,000 litres of liquid coal tar and the remediation of 15,000 tonnes of contaminated soil.

Gas Networks Ireland’s head of asset management, Bobby Gleeson, said the award recognised that the company had employed the most sustainable methods to remediate a historic piece of Limerick’s industrial heritage.

Mr Gleeson said it had been a highly complex remediation which had been made even more challenging by the impact of Covid-19.