The State's 183 largest sources of pollution have been published on the internet by the European Union.
The European Pollutant Emission Register shows that since regulations were tightened in the Republic, there have been significant falls in the amount of pollutant chemical emissions, including sulphur dioxide, nitrogen dioxide and methane.
However, the Republic continues to return its highest carbon emissions for the power generation sector with the ESB's Moneypoint power plant topping the Irish list for highest emissions of a number of environmentally damaging chemicals.
But the Environmental Protection Agency stressed that the inclusion of named facilities does not mean that any particular facility is in breach of its environmental obligations, just that it has been assessed to be among the State's largest producer of pollutant chemicals.
Only larger facilities such as manufacturing plants and pig farms above a certain threshold were included in the monitoring. They were assessed for 50 separate chemicals, discharged either in the air or water.
Overall the Irish results show a a marked reduction in sulphur dioxide, nitrogen dioxide and methane emissions.
It also reveals that Ireland does not have serious outdoor air quality problems. This is largely due to the eradication of the burning of coal in many urban areas during the 1980s and the early 1990s.
Commenting on the results, Dara Lynott, director of the Office of Environmental Enforcement, said the reduction in emissions was welcome.
He said Ireland's national carbon dioxide emissions in 2004 were 3 per cent down on the 2001 levels, reaching 45,266 tonnes in 2004. The register also indicates that sulphur dioxide and methane emissions dropped by 43 per cent and 30 per cent respectively.
Carbon dioxide emissions from industries reporting to the register represent 45 per cent of the national total.
Much of the overall reduction in industrial output of these chemicals is understood to be ascribed to the closure of the IFI fertiliser plants at Co Wicklow and Cork.
In publishing the information, the European Environment Agency said it was required by an EU directive to make information available to the general public to allow them to see the results for a particular area and review its continuing monitoring on the internet.
It facilitates comparisons with similar facilities in other towns or other European countries. Companies may also look at the pollution records of their competitors and increase their own efforts to excel in environmental terms.
The biggest threat now facing Ireland's air quality is emissions from road traffic.
The EPA notes, however, that short-term traffic restrictions to improve air quality would be a major new challenge for local authorities. The EPA has noted that although car manufacturers have made environmental improvements to the vehicles on sale in Europe, the Irish tendency has been towards vehicles with larger engines, which result in a net negative effect on the environment.
A summary report of the Irish Pollutant Emission Register can be found at http://www.epa.ie/OurEnvironment/EPER/. The full EPER report, which includes data by company, along with reports from other countries, will be available on the EPER website www.eper.cec.eu.int/eper.
