Location of Nitrogen Dioxide monitoring stations along M50 in Dublin 15

In July of this year, the Environmental Protection Agency (EPA) published its Environmental Indicators for Nitrogen Dioxide report. Nitrogen dioxide is a gas that emerges from traffic emissions. The EPA have been using diffusion tube in a number of locations around city centre to detect the presence of nitrogen dioxide. Any yearly average concentrations of more than 40 ug/m3 (micrograms) indicates a likely breach of the EU standards. Breaches were detected on a significant number of streets in the city centre.

Modelling done by the EPA suggested that there could be high concentrations of nitrogen dioxide along M50, including within residential estates backing onto it. I sent in a freedom of information request to Transport Infrastructure Ireland (TII) – the body that operates the M50 – asking if they were undertaking testing, how many testing stations they have, what were their results and why they had decided to undertake testing.

TII have recently responded to my information request (see links below). It turns out that since, 2018 they have operated 34 stations along the M50. These have detected levels of nitrogen dioxide of between 19 – 38 micrograms per year. This isn’t a breach of the EU maximum (40 micrograms) but it is very close. TII have created a website where the monitoring at each station can be viewed.  There are 6 stations along the Dublin 15 section of the M50 (see the picture above). Looking at the results from this report (which covered 6 months of monitoring in 2018), the station at Castleknock Dale had 34 ug while that at Hamilton Park/Diswellstown had 33 ug.

It is positive to see that none of the stations have recorded a breach of the 40 microgram level. However, it is concerning to see some are close to breach level. TII needs to make the full year results available to the public. It think it is really important that this information comes out.

It is also vital that we see new policies, both from TII and the Government, to tackle air pollution. The EPA in July demonstrated that many people experience contaminated air while they travel through Dublin city. The information I have uncovered shows that air can also be of poor quality in residential suburbs.

AIE Reply 4 Sept

Internal note re Nitrogen dioxide.