Air quality in Belfast

Is Belfast a city with polluted air?

Belfast is a city located in the northern region of Ireland, being both the capital as well as the largest city situated in Northern Ireland. It is home to over 343 thousand inhabitants, and is counted as the twelfth largest city in the United Kingdom as well as the largest in Ireland. It has a prominent history as a major port city as well as playing a large role in the industrial revolution that took place between the 18^th and 19^th century. It still sees itself today as an important fixture amongst the U. K’s ports, with many industrial docks present, and as such this has played a large part in the continued deterioration of air quality seen in Northern Ireland.

In 2019 Belfast came in with a PM2.5 yearly average of 12.9 μg/m³, a reading that placed it by a fine margin into the ‘moderate’ pollution ratings bracket. This rating requires a PM2.5 reading of anywhere between 12.1 to 35.4 μg/m³ to be classified as such, and implies that whilst the air quality of Belfast is not in a catastrophic situation, it is most definitely far from perfect and could go a long way to improve its pollution levels considerably. This reading of 12.9 μg/m³ placed it in 1555^th place out of all cities ranked worldwide, as well as in 3^rd place out of all cities ranked in the United Kingdom.

What are the causes of air pollution in Belfast?

With a large amount of its industry based around tourism, as well as a large amount of foreign investment coming in, with subsequent infrastructure being built up in the city and surrounding areas, Belfast sees many different sources of pollution occurring, compounded further by meteorological conditions such as changes in the weather and the accompanying change in human behavior and its pollutive impact.

One of the most common and prevalent sources of pollution in Belfast would be that of the automobile industry, with tens of thousands of cars, motorbikes and other vehicles on the road at any given time. This can give rise to massive spikes of pollution, particularly during rush hour periods and in areas where the roads are less accommodating and channel large amounts of vehicles into a small space. The fallout from this is a sizeable amount of aggravating chemicals as well as hazardous particulate matter being left in the air, causing grave health effects on those who live nearby or have to move through these areas of high pollution.

Besides pollution caused by cars, other prominent ones which also have a combustion source as their central cause, include ones such as factory emissions, with industrial zones and power plants all putting out large amounts of pollution due to running on further unclean and unsustainable fuel sources such as coal. Lastly, the burning of firewood, charcoal and other materials in certain households can also be a major contributing factor, with all of the aforementioned points coming together to cause the high PM2.5 readings on record.

What are some of the main types of pollution found in the air in Belfast?

With much of its pollution arising from combustion sources, Belfast would have large amounts of related chemical compounds and particulate matter in the air. These would include prominent ones such as nitrogen dioxide (NO₂) and sulfur dioxide (SO₂), both of which find their release from cars as well as ships, with nitrogen dioxide finding a majority of its release from vehicles, whilst sulfur dioxide can be emitted in larger quantities from ship exhaust due to different regulations regarding sulfur content in ship fuels.

Other pollutants include black carbon and volatile organic compounds (VOC's), both of which are released via the incomplete combustion of both fossil fuels and organic matter. As such, everything from the simple act of burning wood to factory emissions would emit these materials. Black carbon is a potent carcinogen when inhaled, and makes up the majority of soot, often found coated in large quantities in areas that see a high volume of traffic. Some examples of VOC's include chemicals such as benzene, xylene, methylene chloride and formaldehyde.

When is the air quality at its most polluted in Belfast?

Regarding the air quality data collected over the course of 2019, it can be seen that there is a distinct period of higher pollution taking place within Belfast. The beginning months are when the PM2.5 levels are at their absolute highest, whilst the end of the year readings are significantly lower, indicating that the years end is when the air quality is at its cleanest, before the pollution levels rise rapidly as the new year comes around. December came in with a PM2.5 reading of 9.7 μg/m³, coming in within the World Health Organizations (WHO's) target bracket of 10 μg/m³ or less. This contrasted largely with January, which had a reading of 28.7 μg/m³, a reading that was nearly three times higher than the month of December.

This trend continued, with February coming in with a further reading of 36.1 μg/m³, making it the most polluted month of 2019 and the only month to fall into the ‘unhealthy for sensitive groups’ bracket. Whilst levels stayed elevated for the next few months, they also showed a drop at the same time before returning to more appreciable levels in May. So, in closing, the time period between January through to April was when the pollution levels were at their very worst in Belfast, with February being the worst month of the entire year by a considerable amount (five times higher than the lowest reading of the year, which was October at 6.9 μg/m³).

Who is most at risk to polluted air in Belfast?

Whilst every portion of the population is subject to adverse health issues when exposed to excessive amounts of pollution, there are certain groups that are even more at risk. People who live near busy roads or industrial areas are at greater risk for exposure, and looking at the individual aspect of people’s situation, their backgrounds also have a part to play. Young children are a group that can be considered particularly at risk, along with the elderly, those with compromised immune systems or preexisting health conditions, as well as individuals with excessive sensitivity towards chemicals.