Ireland is a country located in the North Atlantic, with close proximity to Great Britain, separated by several different bodies of water such as St. Georges channel and the Irish sea. Geographically it is an island made up mostly of low lying mountains with a significant sized central plain. Its climate is heavily controlled by the Atlantic Ocean, thus giving it a climate that is free from extremes of temperature, which does play a role in its overall level of pollution, with certain geographical traits in any given city or country around the world sometimes helping, or contributing to worsened levels of pollution. In Ireland, the surrounding mountains or hills with flat plains or valleys can often lead to a lack of wind that causes pollution to build up in the air in certain areas, thus raising the ambient year round.
Despite the geography not being as helpful, meteorological traits work in its favor, lacking the extremes of heat often needed to generate certain photochemical pollutants, as well as the extremes of cold that can often lead to large scale use of energy consumption for heating, although of note is that the temperature can still get considerably cold, which inevitably has an effect on pollution levels, particularly when combined with anthropogenic (human related) activities.
Looking at its pollution levels over the year of 2019, it can be seen that Ireland came in with a PM2.5 reading of 10.60 μg/m³, putting it into the ‘good’ ratings bracket, one that requires a very fine margin of entry, between 10 to 12 μg/m³ in regards to its readings of PM2.5.
PM2.5 refers to particulate matter that is 2.5 micrometers or less in diameter, sometimes going considerably lower down to sizes as small as 0.001 microns or less. Due to its incredibly small size, it presents a significant danger to human health, and as such is a major component used in the calculation of the overall quality of air. Other pollutants used in the overall calculation are ones such as PM10, oxides of nitrogen and sulfur as well as ozone. However, due to the pertinence of PM2.5 and its role in air pollution, it will be used mainly to discuss air pollution levels in Ireland.
Irelands PM2.5 reading of 10.60 μg/m³ is a respectable reading of air quality, putting it in 77th place out of all countries registered worldwide, coming in just behind other ones such as Switzerland (10.89 μg/m³) and the Netherlands (10.91 μg/m³). The capital city of Ireland, Dublin, also came in with a good PM2.5 reading of 10.6 μg/m³ over 2019, putting it in 2357th place out of all cities ranked worldwide. So overall, Ireland does have a good quality of air, as its ratings name suggests. However, there are still pollutive issues that need addressing in the country, and it could take further steps to ensure that it gets its yearly average below the World Health Organizations (WHO) target goal of 10 μg/m³ or less for a cleaner quality of air, the closer number is to 0 being the most optimal.
Ireland has numerous causes of pollution, many of which can come together and compound each other, creating higher readings of contaminants and fine particulate matter in the air, sometimes changing from region to region, with certain areas having more prominent sources of pollution than others.
One of the main ones, particularly afflicting more populated cities and busier areas would be that of vehicular emissions, with the numerous cars on the road taking people in and out of the cities, as well as on their daily commutes putting out large amounts of pollution.
Besides personal cars (as well as heavy duty vehicles such as trucks, lorries and buses, many of which run on diesel fuels as well), other sources of pollution that would be of importance in Ireland would be emissions from factories and other related industrial areas, with many of them also utilizing fossil fuels such as coal to provide their needed energy, and diesel for their heavy machinery.
This in turn releases more pollution and fine particulate matter in the air, the different types of which will be discussed in following. Besides the pollution released from the burning of their fuel sources, factories can also give off pollutants related to whatever material is being manufactured in the form of industrial effluence, affecting both the air and in some cases, water supplies and the environment, although water contamination is less of an issue in countries such as Ireland due to more stringent rules regarding industrial waste management.
An example could be those of any factories involved in the recycling or production of plastic related products. They will all inevitably give out fumes that stem from the burning of plastic materials, although with proper containment protocols in place, these fumes can be reduced.
With these two being some of the main sources of pollution, other ones that crop up on the radar of air contamination in Ireland would be practices such as the burning of peat (accumulations of partially decayed vegetation and organic matter, usually unique to bogs and peatlands, in which there many of in Ireland).
Other organic matter such as wood is also used, but dried peat is used in vast quantities throughout Ireland, seeing a lot of use in rural areas or houses that still use traditional methods of heating such as home stoves or fireplaces. These are notorious as leading sources of localized forms of PM2.5 in the air, which can affect people on a small scale in their homes, or on a larger scale when the smoke and particles make their way up into the atmosphere, thus raising the yearly ambient pollution readings.
Observing the data taken over 2019, and utilizing some of the main cities in Ireland, in particular Dublin, Cork and Waterford, it can be seen that some patterns start to emerge, regarding the levels of PM2.5 being picked up on. In fact, this pattern seemed to be universal for the whole of Ireland, with many of its worst readings and poorest air quality coming in on the same months of the year.
Due to the aforementioned weather influences, the cold has a prominent effect on pollution levels in the air, with a drop in temperature correlating with the amount of energy being spent on the heating of homes and businesses, as well as the burning of materials such as peat, wood and coal for further heating of homes, most prominently in rural areas or smaller towns outside the major cities that still resort to traditional heating methods.
Looking at the numbers, there starts to be a noticeable decline in air quality towards the end of the year, with August through to October starting to show signs that the PM2.5 levels were rising, although of note is that many of the cities still remained within the WHO's target goal of under 10 μg/m³ during these months. However, as the trend continues, November and December are when the more prominent changes start to take place, with four cities out of all 8 registered in Ireland going up a bracket into either the ‘good’ ratings or the ‘moderate’ pollution category, with Cork showing the highest PM2.5 reading in the whole of Ireland during December at 14.3 μg/m³.
From here this decline continued into the earliest months of the year, as winter carries on. It is at times such as these when Irelands air would be at its most permeated with smoke, haze and pollution, causing heightened mortality rates that have been reported on consistently in recent years.
In Dublin, February and March came in as the most polluted months of the entire year, with readings of 14.4μg/m³ and 23.6μg/m³ respectively, making March the most polluted month of the year for the capital.
This remained true for the rest of the country, with Waterford having readings of 15.2μg/m³ and 20.6μg/m³ over April, showing that April is quite consistent in its heightened pollution readings, making it the most polluted month out of the entire year for Ireland, with February following closely behind. Other cities that displayed higher readings during February were Finglas with 21μg/m³, Rialto with 22.5μg/m³ and Carlow at 21.1μg/m³.
All of these readings are well up in the ‘moderate’ ratings bracket, coming in over two times the number of any cities yearly average. It is during months such as this that preventative measures become particularly important, especially for those at risk. The wearing of high quality particle filtering masks as well as staying up to date on hourly or daily pollution levels via the air quality maps on the IQAir website or the AirVisual app would go a long way in helping people to stay safe from elevated levels of pollution, which can have a number of disastrous consequences on health.
Contrasting the previous question, as mentioned, the times that displayed the worst levels of pollution in Ireland were in the winter months, despite an aberration in the readings. Though February and April were by far the most polluted months in the country, with both of them consistently coming in with moderate ratings of air pollution, the PM2.5 levels dropped during the month of March, coming in with readings that sat within the WHO's target goal.
Despite this abnormality in the readings, after the most polluted month of April was over, the levels of PM2.5 in the air start to decline fairly consistently, and to use the city of Waterford as an example, after its reading of 20.6μg/m³ in April, it dropped massively to 6.7 μg/m³ in May, then down to 5.6 μg/m³ in June, before reaching its cleanest rating of 5 μg/m³ in July, a month that came across as the cleanest out of the entire year for many of the registered cities. Despite this, there was the unusual exception of Dublin where it actually rose back up into the moderate bracket, just scraping in with a reading of 12.1 μg/m³, contrary to every other city on record in Ireland.
However, that was an exception, and the cities of Waterford, Finglas, Roscommon and indeed every other city in Ireland came in with its best readings during July. The city that had the cleanest PM2.5 number during this month was a tie between Roscommon and Cork, both with 4.1 μg/m³, meaning that the air would be exceptionally clean to breathe during this time and free from the many pollutants that would be plaguing the atmosphere during the earlier months. So evidently, it is during the summer season that Ireland has its best levels of air quality.
With a vast majority of its pollution arising from vehicle emissions, factory and industrial sites as well as the burning of organic materials, the pollutants found in the air would be ones that stem mainly from these sources. Some examples of major pollutants that arise from cars would be nitrogen dioxide (NO2) and sulfur dioxide (SO2), with nitrogen dioxide being of chief prominence, due to its high release from vehicle engines.
It is a chemical compound that can cause irritation to the lungs and throat, as well as triggering off asthma or other respiratory related conditions. It is so prominent in its release from vehicles, that high concentrations of it in the atmosphere or ground level air will often have direct correlations with high volumes of traffic. Other oxides of nitrogen that contribute to pollution levels are ones such as nitric oxide (NO), particularly in the formation of ozone as well as acid rain.
With solid or organic forms of fuel being used in homes such as peat or wood, materials like black carbon would be released, a major component in soot that is also seen released from cars, factories and anywhere that has burning or combustion taking place.
Others would be polycyclic aromatic hydrocarbons, as well as volatile organic compounds (VOC's), some of which would include benzene, toluene, xylene and formaldehyde, all of which have negative consequences on human health, and are incredibly easy to respire due to them being gases at lower temperatures, hence the volatile tag in their name. These are but a few of the main pollutants found in the air in Ireland, with higher volumes being present during the more polluted months of the year.