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Clean Air Together - moving onto Phase-3 later this year!

Note: The next phase of Clean Air Together will be moving to Galway City in August 2023. Further details will be available here in due course.

What is Clean Air Together?

Clean Air Together (CAT) is a citizen science project where people voluntarily sign up to measure levels of Nitrogen Dioxide (NO2) pollution in their local area. NO2 is a traffic-related air pollutant that can cause negative health impacts. NO2 particularly impacts children, people with pre-existing heart and lung conditions such as asthma, outdoor workers, the elderly, and those communities who may be more exposed to air pollution because of where they live or work.


The first Clean Air Together campaign took place in October-November 2021 where approximately 1,000 citizens across Dublin successfully measured NO2 near their home, business, or school. The second Clean Air Together campaign took place in October 2022 in Cork City with over 700 participants measuring NO2 at their chosen locations.

Clean Air Together is a joint project between the Environmental Protection Agency (EPA) and the Environmental Education Unit of An Taisce.

The project aims to create a better understanding of NO2 air pollution in Dublin and Cork City. The citizen measurements will help the EPA develop air pollutant mapping and forecasting models for the whole of Ireland in the Life Emerald Project. This will include the development of an air quality forecast scheduled for completion before the end of 2023. The air quality maps and forecasts will go on to inform policies aimed at improving air quality and lowering levels of NO2.

In total, over 3,000 residents have applied to participate in the Clean Air Together projects to date. This huge level of public interest and the number of valid results points to a public willingness to participate in citizen science and illustrates the success of the initiative. The EPA and An Taisce therefore extends a massive THANK YOU to all who participated, supported, and gathered important data on traffic pollution in both Dublin and Cork City by measuring NO2 outside their property. The work could not have been done without you.


What are the Clean Air Together (Cork CIty) Results?

The map above shows the NO2 measurements gathered by Clean Air Together (Cork City) participants for approximately four weeks in October 2022. You can click on a dot to see the level of NO2 measured at a location of interest.

The results clearly show the impact of traffic on NO2 air pollution levels: the more traffic there is, the higher the levels of NO2.  

When zooming out on the map you can see a trend emerging: higher results represented as orange and yellow dots are mostly present in the city centre and along some of the major roads around Cork City.

Moving outwards to the suburbs and away from major roads, the measurements drop to lower levels of NO2 (light blue). Finally, most of the lowest results (dark blue dots) can be found further away on the outer suburbs of Cork City. 

The pie chart below shows the distribution of Clean Air Together (Cork City) results.


What do the results mean?

A pie chart outlining the results from Clean Air Together Cork City

The pie chart below shows the distribution of Clean Air Together (Cork City) results.

In 6 out of 10 locations sampled, NO2 levels fall into the lowest category (58%).  As expected, this includes locations in the outer suburbs of Cork City and in less trafficked parts of Cork city.

Most other locations are in the next category up (10-20 µg/m3).  In total, the (0-20 µg/m3) category accounted for 93% of the study’s results.  7% of the results fall in the higher categories (> 20 µg/m3).

The highest NO2 levels were found by national roads:

  • Lower Glanmire Road and MacCurtain street (N8)
  • Commons Road, Leitrim Street and Carroll’s Quay (N20)
  • South Link Road (N27)

The results also suggest that the greater the distance between a dwelling and a busy road the lower the NO2 levels. NO2 quickly reduces with distance, for example a long front garden or living on an upper floor of an apartment building can offer some protection against NO2 pollution. This finding is important as Cork City continues to grow and change. 

Check out our guidance document  Understanding the Results - Cork City 


Keep in Mind

Results image on screen

The Clean Air Together results are an indication of the level of NO2 measured over a 4-week period in October 2022.

NO2 levels vary over the year with changing traffic volumes and weather conditions. Therefore, it is best to view the results as a "snapshot", representative of the NO2 levels during that month and not a definitive measurement of NO2. For this reason, the result cannot be compared directly with the EU Air Quality Directive's NO2 annual average limit of 40 µg/m3 or the recently updated World Health Organisation's recommendation that NO2 levels do not exceed an average of 10 µg/m3 annually. 

However, you can keep the recommended values in these guidelines in mind as indicators as to where results in your area lie.



Scroll down to read more examples of what is being done, and what you can do!


Where does NO2 come from?

Nitrogen dioxide (NO2) is an air pollutant that mainly comes from vehicle traffic. NO2 levels change throughout the year because of:

  • Traffic: As NO2 is a traffic related pollutant, the emissions are higher around busy roads than quiet country roads.
  • Weather: Weather can significantly influence how much NO2 is in air we breathe. In windy weather, pollution can move around whereas on very still, warm days pollution can hover, and may be higher.
  • Ventilation: The size of your surrounding streets can affect how much air pollution is in your area. A narrow street with tall buildings can be more polluted than a wide street with lower buildings as there is less space for air to move around.


Why does NO2 matter for your health and the environment?

Image of cars with NO2 in clouds above buildings including Clean Air Together Logo in the centre

Being exposed to NO2, even for short periods, can have harmful effects on our health and wellbeing. Short-term exposure to NO2 is linked to adverse respiratory effects including airway inflammation in healthy people and increased respiratory symptoms in asthmatics. Long-term exposure is associated with increased risk of respiratory infection in children. Research from Trinity College shows that over 50’s living in Ireland in areas with higher levels of NO2 are more likely to have asthma.

NO2 pollution also impacts the environment. It affects the quality of fresh water, soil, and ecosystems, and NO2 can be absorbed to the atmosphere and later fall as something called ‘acid rain’ that can damage plant life and buildings. NO2 also behaves like a greenhouse gas.

EPA monitoring and computer modelling shows that in some urban areas NO2 pollution is increasing. The EPA in collaboration with the Local Authorities manages a national network of air monitoring stations. The EPA has 110 monitoring sites throughout the country, 5 of which are in Cork. Real-time air pollution data can be seen on

While NO2 is one of the main ambient air pollutants of concern in Ireland, there are other air pollutants of high concern such as Particulate Matter (PM). To learn more about how other air pollutants can impact your health and the environment, and what is being done to lower their levels go to


What is being done and what can be done to reduce NO2?

There are many ongoing initiatives in place that aim to reduce levels of NO2 in Cork City and Ireland - and there are actions you can take to help too!

  1. What is being done by the Local Authorities and the government?

Cork City Council adopted their Clean Air Strategy in 2021 while at a national level the Climate Action Plan (2021), and the New National Investment Framework for Transport in Ireland (2021) have been adopted which all comprise of actions that will help reduce levels of NO2 across the country. These actions include among many:

  • Building more and safer cycle lanes and footpaths.
  • Investing in clean public transport and exploring the development of low emission zones. There are now multiple hybrid buses running in many towns / cities.
    • In April 2022, Cork City Council launched Ireland’s first Clean Air Zone (CAZ). The area encompasses Oliver Plunkett Street and adjacent streets (part of the main shopping and commercial areas in the city) and involves restricting vehicle access to the area other than deliveries (morning and evening) and creates a pedestrian priority zone. Other such pedestrian priority zones exist at Rory Gallagher Square and adjacent streets.
  • Planning to apply the 15-minute city development concept more frequently. A 15-minute city is a neighbourhood in which you can access your day-to-day needs within a 15-minute walk of your home (think schools, access to health professionals, groceries, etc.).
  • Building more electric-vehicle (EV) charging stations and making it more accessible to purchase an EV as your next vehicle purchase.


What Can You Do?

Animated image shows a cyclist on a cycle path in the foreground, a green bus is in the background on the road and pedestrians are walking on the footpath

There are many simple steps you can take. Collectively, these steps can have a big impact on reducing the levels of NO2 across Cork City.

YOU can:

  • Think twice before using your car. One less journey a day or week can make a big difference!
  • Try to walk or cycle on shorter trips instead of using your car. This emits zero emissions and is a step towards a healthier lifestyle. Enquire with your company about the Bike to Work Scheme, safe and secure cycle parking and changing facilities at work.
  • Use public transport if it is an option for you instead of driving for longer journeys.
  • Alter your driving habits and switch off your engine when your vehicle is stopped. This helps to reduce NO2 emissions and reduce the amount of pollution pedestrians and cyclists will breathe in from your vehicle
  • Support flexible working arrangements such as home working to reduce the number of vehicles on the road
  • Raise any concerns with your local public representative and get their support for cleaner air and healthier communities
  • Could you consider an electric vehicle for your next purchase?
  • Consider buying more local goods. Many items have travelled long distances to get to the supermarkets and each journey your purchased goods have made raises the amount of air pollution for other citizens and animal life on the planet


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Most importantly share the message!


Never doubt that a small group of thoughtful, committed citizens can change the world; indeed, it's the only thing that ever has
Margaret Mead (Anthropologist).