Ireland’s air quality currently is good, relative to other European Union (EU) Member States, but maintaining this standard is a growing challenge. Despite our monitored air quality being within EU limit values, the levels of particulate matter is of growing concern, especially during the winter months when domestic solid fuel burning can directly impact on air quality and on our health. In our larger urban areas we face potential exceedances of nitrogen dioxide limit values unless we reduce our dependence on the private motor car.
The World Health Organisation (WHO) estimates show that more than 400,000 premature deaths are attributable to poor air quality in Europe annually. In Ireland, the number of premature deaths attributable to air pollution is estimated at 1,510 people and is mainly due to cardiovascular disease. The WHO has described air pollution as the ‘single biggest environmental health risk’.
The ambient air quality pollutants of most concern on an EU-wide level are nitrogen dioxide, particulate matter (PM), ozone and PAHs. They can impact on human health, ecosystems and vegetation and monitoring is carried out to determine their concentration levels.
Nitrogen Oxides (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.
The NO2 concentrations in Ireland were static for the period 2008‑2015, perhaps because of a combination of the economic downturn and favourable weather. It will be important to remain vigilant to increasing NO2 levels, particularly from transport, in light of the economic recovery.
Particulate Matter (PM10 and PM2.5)
There are many sources of particulate matter (fine particles) including domestic solid fuel burning, diesel fuelled vehicle emissions, agriculture and even natural sources such as sea salt and wind-blown dust. These small particles can penetrate the lungs and cause health effects. There are two main types - PM10 (diameter less than 10µm) and PM2.5 (diameter less than 2.5µm).
PM2.5 tends to be a better signifier of man-made pollution, whereas PM10 can have a greater contribution from natural sources. In Ireland, levels for both PM10 and PM2.5 are above the WHO air quality guidelines values. Bringing the PM levels down below the WHO guideline values will be a challenge, requiring co-operation across a number of sectors.
Polycyclic Aromatic Hydrocarbons (PAHs)
PAHs are organic compounds predominantly originating from solid fuel burning, particularly wood burning and, to a lesser extent, vehicle emissions. A reduction in the use of solid fuel as a home-heating source across Ireland would mitigate PAH impact on air quality into the future.
Ground Level Ozone (O3)
At ground level, higher concentrations of ozone in the air have adverse implications for human health, 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 but are low in comparison with those in mainland Europe.
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. Average concentrations in Ireland are generally below the thresholds for effects on human health and vegetation set down in the Clean Air for Europe (CAFE) Directive, but can exceed the WHO air quality guideline values for ozone.
Dioxins and PCBs
"Dioxins” is a collective term for over 200 chemical compounds, of which 17 are considered to be of toxicological significance. These compounds arise mainly as unintentional by-products of incomplete or poorly controlled combustion (e.g. backyard burning of waste) and from certain chemical processes. To maintain surveillance of dioxins, the EPA conducts surveys based on levels found in cows’ milk. All dioxin levels recorded in these surveys have been well below legislative limits and compare favourably with those from previous surveys and from other EU countries.
In Ireland the premature deaths attributable to air pollution are estimated at 1,200 people. The most significant air emissions are PM10 and PM2.5 which mainly arise from domestic solid fuel burning. The most common cause of premature death attributable to poor air quality is cardiovascular disease. The economic impact is also significant, with the increased costs of healthcare and lost working days.
Comparison of national ambient air monitoring results with WHO guideline values for particulates and PAHs shows the need for progress with regard to reducing levels of emissions attributable to residential heating. The burning of solid fuel is a source of particulate matter (PM) and other air pollutants including SO2 and PAHs. PM and PAHs arise from domestic solid fuel burning, which particularly impacts air quality in areas where the sale of bituminous coal is permitted.
New EU emissions standards for vehicles, cleaner technology, and a reduction in the number of vehicles using the roads as a result of the economic downturn led to a decrease in NO2 in our urban centres. However, economic recovery will most likely lead to an increase in NO2 levels. The failure of real-world emissions of NOx Euro 5 class vehicles to meet the standards set for them has had a disproportionate impact on ambient air. As a result, projections of NO2 emission reductions did not come true and an increase in vehicle numbers actually led to increasing NO2 levels across Europe.
Air pollution has a transboundary aspect meaning that emissions from one country can be transported via meteorological 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), volatile organic compounds (VOCs), and ammonia (NH3). These pollutants can contribute to acidification, eutrophication and ground-level ozone formation, but they have shown declining concentrations since the introduction of recent legislation.
Air Quality Data
Limit values have been established by the European Union based on contributions by environmental and health experts in order to help mitigate the impact on Member State populations. Upon exceedance of these limit values, Member States must implement air quality plans to assess and combat the problem.
The WHO has devised air quality guidelines in order to inform policymakers and provide appropriate air quality targets worldwide, based on the latest health information available. Since 2012, the EPA’s annual reports have been assessing air quality against these much more stringent air quality indicators. There have been exceedances of the guideline values for particulate matter, ozone and PAHs and the EPA has called for the adoption of these more stringent WHO guidelines in Europe for particulate matter and ozone.
What's Being Done?
European Union (EU) Legislation
Limit values have been established by the EU to help mitigate the impact on Member State populations. Upon exceedance of these limit values, Member States must implement air quality plans to assess and combat the problem. A national monitoring network supplies real-time data on air quality to the Irish public and there are plans to greatly expand this network. Since 2012, Ireland has not exceeded any EU legislative limit or target values at the stations in the current monitoring network.
The EPA co-ordinates and manages a nationwide network of 31 monitoring stations which measures the levels of air pollutants and delivers this information to the public. The EPA is developing a new National Ambient Air Quality Monitoring Programme, which should involve a greatly expanded national monitoring network providing enhanced real-time information to the public, as well as an increased local authority capacity to conduct indicative air monitoring. There will also be various citizen science initiatives to encourage greater engagement of the public in air quality issues. These changes should greatly improve our national capacity for air quality and public health protection.
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.
Comparison of national ambient air monitoring results with WHO guideline values for particulates and PAHs shows the need for progress with regard to reducing levels of emissions attributable to residential heating. The ban on the marketing, sale and distribution of bituminous fuel (the “smoky coal ban”), which was first introduced in Dublin in 1990 and extended over the intervening period to 26 other cities and towns, has proved effective.
The full implementation of a nationwide smoky coal ban by 2018 should help to improve air quality for the air everyone breaths. However, continued use of peat and wood will contribute to air pollution in residential areas. EPA funded research currently being undertaken aims to deliver detailed information on the chemical composition and sources of airborne particulate matter in rural and urban residential areas of Ireland so as to assist appropriate health focused policy interventions.
Ongoing non-compliance with NOx ceiling levels is a concern and needs to be addressed. The actions set out in The Department of Transport’s Smarter Travel – A Sustainable Transport Future should be implemented to improve air quality. These include actions to reduce travel demand, increase alternatives to the private car and improve the efficiency of motorised transport. Enhanced incentives to encourage vehicle owners to switch to electric options should also be encouraged.
Emissions from Industry
Industrial Emissions (IE) and Integrated Pollution Control (IPC) licensing, enforced by the EPA, help to curb emissions from industry and the power generation sectors in Ireland. The introduction of the Medium Combustion Plant Directive will have a positive impact on emissions from industry.
EPA Air Research Programme
Between 2007 and 2015, the EPA funded over 50 air-related research projects. The air research theme deals with (1) urban and rural air quality, (2) transboundary air pollution, (3) ecological effects, as well as health impacts, (4) emissions inventories and projections, (5) sources of air pollution, notably industrial, agricultural, residential and transport and (6) cross-cutting issues with climate change. The outputs of EPA-funded research have informed national thinking, contributed to EU analysis, and have been presented and used in various UN forums.
A key future challenge for Ireland is in decreasing our particulate matter, PAHs and ground level ozone concentration levels below the more stringent 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). This NERT requires Ireland to decrease annual average PM2.5 concentrations by 10% by 2020, a reduction which will prove challenging if activity in a number of sectors increases without any consideration of abatement or alternatives.
Tackling transport sector pollutants will require a combination of secured national investment, advancements in technology, policy developments and, a shift in behaviour by us as individuals. Emphasis and priority should be given to public transport or clean transport over conventional internal combustion vehicles in all aspects of society. However, it is the individual choices that people make that will have the most immediate and greatest impact on transport emissions in our urban areas where NO2 is problematic and where public transport is a viable option.
Domestic Fuel Burning
Continuing emissions from domestic solid fuel use are contributing to high levels of particulate matter and PAHs in villages, towns and cities. The nationwide ban on smoky coal due in 2018 will have an impact on levels of particulate matter, particularly in rural towns and villages. However, there is a need for regulation of solid fuel beyond coal.
Peat burning is still prevalent in many parts of the country – most particularly in rural areas – and contributes significantly in terms of particulates. Wood and peat burning is emerging as a potentially significant contributor to PAH and particulate matter levels in Ireland, along with a wide variety of other solid fuel products that are on the market.
Essential to the goal of improving our air quality will be a shift for Irish consumers from solid fuel to cleaner fuel alternatives, along with an awareness of the impact our choice of fuel for home heating has on the air quality and the impacts on our locality. Incentives for people to use alternatives should continue to be encouraged at a national level.
Pathway to Good Air Quality
The implementation of the revised National Emissions Ceiling (NEC) Directive across Europe, as part of the EU Clean Air Policy Package, will have a positive impact on pollutant levels in Ireland, particularly NOx, and possible future impacts for ammonia. A rise in ammonia through agricultural expansion could lead to an increase in the secondary formation of particulate matter. Measures such as anaerobic digestion of animal wastes with associated energy recovery and low-emission land spreading practices can have multiple benefits for air quality, water quality and climate change.
Many of the sources of air pollutants are also the sources of greenhouse gases, so an increased understanding and policy alignment of air quality and climate change is essential. More research is needed into the links between air quality and public health. This understanding will help to identify the critical issues and help policymakers implement the necessary changes to improve our air quality and associated public health.