Monitored Air Quality Parameters

In Cork City there are 4 monitoring stations that are part of the EPA's National Ambient Air Quality Network that monitor the levels of parameters such as - Particulate Matter (PM), Nitrogen Oxide (NO2), Sulphur Dioxide (SO2), Ozone (O3), Benzo (a) Pyrene, Lead, Cadmium, Nickel, Arsenic.  

In addition there are a number of air quality sensors across the city that monitor levels of Particulate Matter (PM2.5).  Visit to view the network.

The pollutants of most concern are those whose main source is traffic such as Nitrogen Dioxide (usually referred to as NOx) and Sulphur Dioxide; and Particulate Matter produced mainly from the burning of solid fuels. 

Particulate Matter (PM)

The most commonly measured units of dust particles in the air are PM2.5, PM10 and PM1.  PM10 is particulate matter which is 10 microns or less in diameter, PM2.5 is particulate matter which is 2.5 microns or less in diameter and PM1 is particulate matter which is 1 micron or less in diameter. As a comparison, the width of a human hair is around 100 microns so approximately 40 fine particles will fit along its width. PM2.5 is generally described as fine particulates.

Nitrogen Oxide (NOx)

NOx is the collective term for the gases nitric oxide (NO) and nitrogen dioxide (NO2). Emissions from traffic are the main source of nitrogen oxides (NOx) in Ireland, along with electricity generating stations and industry. Short-term exposure to NO2 gas is associated with adverse respiratory effects, while NOx in general contributes to the formation of ground-level ozone and acid rain.

 Sulphur Dioxide (SO2)

The main source of sulphur dioxide in Ireland is from burning coal and oil to heat homes and industrial plants as well as emissions from electricity generation.

SO2 is an irritant gas which attacks the throat and lungs. Prolonged exposure can lead to increases in respiratory illnesses like chronic bronchitis. It contributes to the formation of acid rain which damages vegetation and buildings.

Levels in Ireland are low to moderate. Levels of SO2 have decreased over recent years due to increased use of low-sulphur "smokeless" coal, increased use of natural gas instead of solid fuels and reduced industrial emissions through IPC licensing. 


Ozone is a natural component of the atmosphere. Most ozone is found high up in the stratosphere, the layer of the atmosphere between 12km and 50km above sea level. Stratospheric ozone is essential to life on earth as it protects us from harmful rays from the sun.

Ozone is also found in the troposphere, the layer of the atmosphere next to the earth. Exposure to high concentrations of tropospheric ozone causes chest pains, nausea and coughing in humans.

Long term exposure to moderate concentrations causes a reduction in lung capacity and can worsen heart disease, bronchitis, emphysema and asthma. Tropospheric ozone contributes to the greenhouse effect and subsequent global climate change.

Levels of ozone in Ireland are moderate.

For queries on Cork City Councils Air Quality Monitoring Programme please email