Air quality in Ireland compares favourably with other European Union (EU) countries, but health impacts associated with air pollution in Ireland is still an issue that requires further measures. A 2014 report by the European Environment Agency (EEA) indicates that around 1,200 deaths in Ireland in 2012 were directly linked to air pollution, while for Europe the figure was approximately 400,000 deaths.
Some pollutants like tiny airborne particles and ground level ozone can trigger respiratory problems, especially for people with asthma. While air quality in Ireland is of a good standard, monitoring shows that levels of some pollutants are at concentrations that may impact on health, including nitrogen dioxide which mainly arises in large towns and cities as a result of traffic emissions.
The ambient air quality pollutants of most importance on an EU-wide level are nitrogen dioxide, particulate matter and ozone. They can impact on human health and are at levels approaching the relevant limit value or long-term objective.
Nitrogen Dioxide (NO2)
Emissions from traffic are the main source of nitrogen oxides in Ireland, along with electricity generating stations and industry. Nitrogen dioxide can affect the throat and lungs, while long-term exposure is associated with increased risk of respiratory infection in children. Oxides of nitrogen contribute to the formation of acid rain and of ground-level ozone.
While ambient NO2 levels in Ireland are moderate, they are rising due to increasing traffic volumes. As a result of difficulties in achieving emissions reductions from road traffic, the 2013 emissions of NOx are above the 2010 limit as set out in the EU National Emissions Ceilings (NEC) Directive. However, compliance with the ceiling will depend on the outcome of the adjustment procedure application used to estimate the effect of inventory improvements and the inclusion of new source categories which were not foreseen when the 2010 ceilings were set.
Particulate Matter (PM10)
There are many sources of particulate matter (dust) including vehicle exhaust emissions, soil and road surfaces, construction works and industrial emissions. Particulate matter (PM) can be formed from reactions between different pollutant gases. Small particles can penetrate the lungs and cause damage. These are known as PM10 (diameter less than 10µm) and PM2.5 (diameter less than 2.5µm). There are higher levels of PM10 in many cities and towns at traffic influenced sites. However, in smokeless fuel zones, levels of particulate matter decreased after the ban on bituminous or ‘smoky’ coal.
At ground level, higher concentrations of ozone in the air have adverse implications for human health and for crops and other vegetation. With respect to human health, high concentrations of ozone affect the functioning of the respiratory system. Levels in Ireland are highly influenced by transboundary sources and are higher at the west coast than in the east of the country.
In Irish urban areas, ozone is depleted through reactions with traffic-emitted pollutants; therefore levels of ozone are higher in rural areas than in urban areas. Ozone concentrations are strongly influenced by meteorological conditions; higher levels of ozone occur in warm sunny conditions.
Air Quality Data
The results of air monitoring are compared to limit values set out in EU and Irish legislation on ambient air quality. In 2014, measured values of sulphur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), Ozone (O3), particulate matter (PM10 and PM2.5), heavy metals, benzene and polycyclic aromatic hydrocarbons (PAH) were below the legal limit, and target values as set out in the Clean Air for Europe (CAFÉ) Directive, and 4th Daughter Directive.
However, when some of these parameters are compared to the tighter World Health Organisation (WHO) Air Quality Guideline values, then Ireland is above these guideline values with respect to PM10, PM2.5, ozone, and PAH. This may have important implications, if these WHO guideline values are adopted as limit values by the EU, and given the significant mortality rate that is directly linked to air pollution in Ireland.
Almost 1,200 deaths in Ireland in 2012 were directly linked to air pollution, while for Europe the figure was approximately 400,000 deaths. The most significant air emissions are PM10 and PM2.5 which mainly arise from traffic emissions and particularly from diesel engines. Other traffic emissions that can be harmful to human health include nitrogen dioxide (NO2), carbon monoxide (CO), volatile organic compounds (VOCs), and heavy metals. In Dublin and Cork concentrations of NO2 are close to the specified EU limit value at monitoring stations near busy roads.
The burning of coal and other solid fuel is also a source of particulate matter (PM) and other air pollutants including SO2 and PAH’s. The ban on bituminous coal in large cities and towns has greatly reduced levels of particulate matter in those areas. PM and PAH’s arise from domestic solid fuel burning, which particularly impacts air quality in areas where the sale of bituminous coal is permitted. As a result, levels of PM in smaller towns are similar or higher than those in cities, where bituminous coal is banned.
Air pollution has a transboundary aspect meaning that emissions from one country can be transported via meterological conditions to other countries. National emissions ceilings are in place across Europe to control emissions of four key transboundary pollutants: sulphur dioxide (SO2), oxides of nitrogen (NOx), VOCs, and ammonia (NH3). These pollutants can contribute to acidification, eutrophication and ozone formation.
Strategies implemented in Ireland in recent years have substantially reduced emissions of SO2, VOCs, and NH3, but levels of NOx are expected to remain high in the short term. The benefits associated with the increased use of catalyst control technology for reducing industrial NOx emissions, have been offset by increases in road transport that are responsible for higher NOx emissions levels.
Dioxins and PCBs
The most appropriate method for assessing dioxin exposure in the air is to sample dioxin levels in cows’ milk samples taken during the grazing season. These can be used as indicators for the actual average local dioxin exposure by atmospheric deposition. The 2014 Environmental Protection Agency (EPA) survey on dioxin and PCB levels in the Irish environment shows that the levels tested for all samples were well below the relevant EU limits, and compare favourably with the results from previous surveys and from other EU countries.
What's Being Done?
Ireland has seen a significant improvement in its ambient air quality since the introduction of a number of legislative measures around acid rain, and photochemical smog, beginning in the early 1990s. Despite these recent improvements, Ireland faces new challenges with regard to its air quality arising from assessment of previously un‐monitored pollutants, and an increasing understanding of the impacts of historically important air pollutants.
European Union (EU) Legislation
The Clean Air for Europe (CAFÉ) Directive and the Fourth Daughter Directive (2004/107/EC) set limits and target values for ambient concentrations of air pollutants harmful to human health and the environment. If any limits are exceeded, Member States (MS) must implement measures to ensure the air quality standards are met. A comprehensive monitoring network supplies real-time data on air quality to the public.
Air Quality Index for Health
The EPA’s Air Quality Index for Health (AQIH) is a number from one to 10 that tells the public what the air quality currently is in their region, and whether or not this might affect the health of you or your child. A reading of 10 means the air quality is very poor and a reading of one to three inclusive means that the air quality is good. The AQIH is calculated every hour, and you can see the current readings at www.epa.ie/air/quality/index. The AQIH can be used by health professionals to help patients who are sensitive to air pollution manage their condition and reduce their symptoms.
Smoky Coal Ban
The ban on the marketing, sale and distribution of bituminous fuel (or ‘smoky coal ban’) was first introduced in Dublin in 1990 in response to severe episodes of winter smog from the widespread use of bituminous coal for residential heating. The ban proved very effective in reducing smoke and sulphur dioxide levels and was subsequently extended to other areas.
The ban now applies in 27 cities and towns, and now also includes a ban on the burning as well as the sale of bituminous coal. Air quality monitoring by the EPA has shown levels of particulate matter (PM10) are lower in these areas than in towns where the ban does not apply. The EPA is supportive of a longer term nationwide ban on bituminous coal, subject to further Regulatory Impact Assessment and consultation with the Northern Ireland authorities - see the EPA Review of the Smoky Coal Regulations.
While new standards and cleaner technology have reduced car emissions, this has been offset by the increasing number and bigger engine sizes of vehicles on Ireland’s roads. Diesel cars are more fuel efficient (i.e. less CO2), but they do produce more NOx and particulates than petrol cars. Switching vehicle taxation to CO2 emissions in 2008 was an attempt to incentivise more sustainable transport choices. In 2008, average CO2 emissions of new cars fell by 13 per cent, and estimated total emissions declined by 5.9 KT CO2 due to a significant switch to diesel cars. However, as the economy recovers, then traffic emissions will increase unless there is a further intervention to reduce NOx emissions and achieve compliance with the National Emissions Ceilings Directive.
Emissions from Industry
The continued implementation and enforcement of existing policy measures is vital to maintain Ireland’s good air quality. The EPA has reported high compliance rates with air pollutant emission limits specified in industrial and waste management licences for parameters such as VOCs, particulates, SO2, and NO2.
The key future challenge for Ireland is in decreasing our PAHs, PM10 and PM2.5 concentrations to below the World Health Organisation (WHO) air quality guideline values. The complex relationship between achieving a reduction in our carbon footprint as well as simultaneously reducing our PM2.5 concentrations needs to be addressed as part of the EU National Emissions Reduction Target (NERT) for 2020. This NERT requires Ireland to decrease annual average PM2.5 concentrations by 10%, a reduction which will require commitment and cooperation across all sectors of Irish government, industry and society.
High NOX emissions within urban centres may lead to an exceedance of the limit value in the future due to our continued reliance on motorised vehicles. The actions set out in the Smarter Travel Policy for Sustainable Transport should be implemented. These include actions to reduce travel demand, increase alternatives to the private car, reduce the NOX emissions of motorised transport, and by considering our choice of motor vehicle fuel. This process will require joined‐up action between Government departments, national agencies and local authorities, to make air quality an integral part of their traffic management and planning processes.
Domestic Fuel Burning
The EPA presented air quality data in previous annual reports showing that air quality is worse in smaller towns, than in large urban areas that had a bituminous coal ban. In 2011, additional regulations were introduced which require that all bituminous coal for residential use must have a sulphur content of no more than 0.7%. Currently, there are 27 smoky coal ban towns and cities throughout the country.
At the heart of the issue is the choice by individuals to switch from solid fuel to gas or other low emission fuels or at least implement the use of efficient stoves to burn solid fuel which can further reduce domestic emissions of air pollution. However, any shifting from gas or other low emission fuels to a solid fuel stove, even an efficient one, will result in a net increase in emissions, particularly of PM, NOX and PAH.
Health and Air Quality
A much greater emphasis on energy efficiency measures to bring about a reduction in the overall use of heating fuels, particularly solid fuels, is also needed. Given the significant annual mortality rate directly linked to air pollution, the links between health and air quality must be better communicated by all public bodies involved in air quality assessment and management, to raise awareness of the critical issues with policy makers, and with the public.
An emphasis on the health benefits of clean air, and its value as a resource must be stressed, so that ‘buy‐in’ from the public can be achieved with regards to protecting our air quality.