Which Pollutants Are Dangerous?

While all pollutants in the atmosphere cause harm to the planet, there are some that are more dangerous than others. The more dangerous air pollutants are:

Sulphur Dioxide – high concentrations can result in breathing impairment for asthmatics who are active outdoors. As can be seen from the graph below, levels have been consistently low in Ireland since 2002, with a slight downward trend. This trend is reflective in the shift in fuel choice across Ireland in both the residential heating sector and the energy production sector. This shift has been from sulphur containing bituminous coal to those fuels which are low in SO2 production, such as natural gas (EPA, 2013).

Trend in SO2 Concentrations.
Air Quality Report 2012 (EPA, 2013).


Ozone at ground level - exposure to this can irritate breathing, decrease lung function, inflame airways and worsen lung conditions such as asthma. It can also affect crops and other vegetation and even buildings. 

Lead – Extended exposure may lead to seizures, mental problems and behavioural disorders. At low doses lead exposure is linked to damage of the nervous systems in young children.

Carbon monoxide - CO reduces oxygen in the blood stream, when it enters the body through the lungs. The danger of this pollutant increases in people who suffer cardiovascular diseases such as angina.

Benzene– Long term inhalation can cause disorders in the blood – including reduced red blood cells and anemia

Particulate matter  – These particulates are so small that they get deep into your respiratory tract and increase the risk of disorders.

Oxides of Nitrogen – it has a direct effect on health, as short-term exposure reduces lung function while long term exposure is linked to increased risk of respiratory infection in children. NOx levels in urban areas are influenced by weather episodes, which accounts for some of the variation seen in annual results.

A period of stable airflow over a city centre can lead to a build-up of NO2. The reason for the decrease in NO2 concentrations in 2010, 2011 and 2012, shown in the graph below, could partly be due to meteorological conditions. However, this decrease is also reflected in Ireland’s national emissions inventory figures, which show a declining trend in NOx emissions generally since 2005 and a 10% reduction between 2010 and 2011 alone (EPA, 2013).

Trend in NO2 Concentrations.
Air Quality Report 2012 (EPA, 2013).

Persistent Organic Pollutions

POPs, or Persistent Organic Pollutions, are chemical substances that can have serious effects on health and the environment. Evidence shows that these substances can be transported far across international boundaries, impacting on the environmental and health across the globe. To address this problem, many nations have signed international conventions on POPs.

Ireland is a signatory to the 1998 (Aarhus) Protocol on Persistent Organic Pollutions (POPs) to the UN Convention on Long-Range Transboundary Air Pollution. It is also a signatory to the 2001 UNEP Stockholm Convention on POPs.

POPs regulations 2010 prohibit the production, use or placing on the market of POPs and restricts the use of other substances. It also includes provisions for the management of waste consisting of, containing or contaminated by any of these substances.

In Ireland, the management of waste containing POPs is integrated into the EPA’s waste licensing and permitting systems.

Volatile Organic Compounds

Volatile Organic Compounds (VOCs) are air pollutants that are harmful to the environment and can also affect human health. They can contribute to respiratory illnesses, and some can cause reproduction problems and be harmful to the unborn. Vehicle emissions, commercial and industrial activities using organic solvents, pharmaceutical manufacturing and dry cleaning are some of the sources of VOCs.

Control on the emissions of VOCs from various sectors were introduced through the Emissions of Votatil Organic Compounds from Organic Solvents Regulations 2002. Further controls on the VOC content of certain products were introduced in the Limitations of Volatile Organic Compounds due to the use of Organic Solvents in Certain Paints, Varnishes and Vehicle Refinishing Products Regulations 2007. Under the 2007 Regulations, new certification requirements for vehicle refinishing instalments were introduced.

On an EU level, the emissions of VOCs are addressed by the Directive on National Emission Ceilings.

previousPrevious - Air Pollution Act 1987
Next - Where Do They Come From?next