Air quality in Edinburgh

Does Edinburgh suffer from bad levels of pollution?

The city of Edinburgh is located in the northern region of the United Kingdom. With a decent level of elevation (some 154 feet above sea level) as well as having a close proximity to the coast, it is afforded a good level of protection against the build up of pollution that many landlocked cities suffer from. Observing the data taken from past recordings, in 2019 Edinburgh came in with a reading of 6.6 µg/m³ in regards to the level of PM2.5 found in the air.

PM2.5 refers to fine particulate matter that is 2.5 micrometers or less in diameter, giving it an incredibly small size that has the potential to wreak havoc on the human body when inhaled. This is why it is used as a standard to measure levels of air pollution, as with high levels of fine materials in the air often being an indicator that there is a pollution problem that needs addressing. To return to Edinburgh's readings, 6.6 µg/m³ is well within the World Health Organizations (WHO) target goal of 0 to 10 µg/m³ and would make for a very clean quality of air to breathe year-round.

However, there were a few instances of slightly elevated pollution levels, with a few reasons behind them, which will be discussed further on. The months in question were February and April, which both came in at different ratings from the rest of the year, with April being particularly high with a reading of 14.2 µg/m³. This shows that whilst the air in Edinburgh is extremely clean, being number 3930 out of all cities ranked worldwide, as well as 108^th place out of all cities ranked in the United Kingdom, there are a few instances in which its citizens will be exposed to sudden spikes in PM2.5 that could have detrimental effects to those caught in these high pollution zones.

What are some of the main causes of pollution in Edinburgh?

The main causes of pollution in Edinburgh would find their root in vehicle emission and wood burning stoves. Due to the extremely cold temperatures that Edinburgh can drop to, during winter months large amounts of wood and other organic materials (as well as fossil fuels) are burnt in order to warm the many houses up and down the city. The burning of wood releases a multitude of chemicals into the air, and although in times past this was a highly practical and acceptable way of keeping warm during the colder months, in the modern era with ever growing populations, practices such as this are coming under increased scrutiny due to the sheer number of people resorting to them, and with that great number comes a greater amount of pollution.

Wood burning, in addition to fine particles of various forms of carbon it puts out, can release pollutants into the air such as benzene, formaldehyde, acrolein and polycyclic aromatic hydrocarbons (PAH’s). These are some of the more unconventional and lesser well-known contaminants that can be released from the burning of wood, with others also being emitted such as carbon monoxide (CO) and nitrogen dioxide (NO₂), both of which can also be expelled in large quantities from car exhaust fumes.

Other pollutants that may arise from wood burning practices and stoves are black carbon and volatile organic compounds (VOC’s), both of which are caused by the incomplete or improper combustion of organic matter and fossil fuels. Black carbon is highly dangerous with many health effects. It is also a primary component of soot, and as such can be found accumulated around areas where fires have occurred, as well as areas that see high volumes of traffic (often seen in many underpasses and highways coating walls and railings with thick black particles).

Many of the pollutants that are released from wood burning stoves can also be found in car exhaust fumes, comprised of both primary and secondary pollutants. A primary pollutant is one that is released directly from the source, such as a fire or from car exhaust. Secondary pollutants are ones that form in the atmosphere through chemical reactions involving the bonding of these primary pollutants. Of note is that certain pollutants can be both simultaneously, such as nitrogen dioxide. It is emitted directly from car exhaust and fires, and also form in the atmosphere as a secondary pollutant. These are the main causes of poor air quality in Edinburgh.

What are some of the health issues associated with breathing smoke in Edinburgh?

Health effects of breathing in smoke released from the burning of wood, or improperly maintained wood stoves can have a number of serious effects on a person’s health. For one, carbon monoxide can actually cause instances of fatalities occurring in houses, although this is more common with poorly maintained boilers and other units aside from wood stoves. Wood smoke (as well as exhaust fumes) have high concentrations of PM2.5 and PM10 in them, including the previously mentioned black carbon. Inhalation and exposure to these particles can cause health effects such as irritation and inflammation of the lining of the lungs and respiratory tract, as well as chest infects. Irritation to the eyes, ears and skin can occur, along with aggravated asthma attacks in those suffering from it.

The microscopic PM2.5, can enter deep into the alveoli and constrict the amount of oxygen that the lungs can take in over time. This can lead to a reduction in lung function, as well as increased risk of lung cancer. Unborn babies exposed to these pollutants whilst in the womb run the risk of being born with birth defects, as well as being underweight at birth, with cognitive or mental defects, and risks of miscarriage also possible. These are but a few symptoms of the effects of being exposed to higher levels of car exhaust and burnt wood smoke.

When are pollution levels in Edinburgh at their worst?

Going off the data given, as well as previously mentioned, Edinburgh saw its worst month in April, with a surprisingly high reading of 14.2 µg/m³. This is over 3 times higher than its lowest recorded number in 2019 (October with a reading of 3.9 µg/m³). Another elevated reading was taken during 2019 in February, with a reading of 10.5 µg/m³. This is indicative that Edinburgh suffers from its worst pollution levels at months around the beginning of the year, although this may differ from year to year due to weather conditions and human activities.

How can Edinburgh reduce its pollution levels?

From observing the main causes of pollution in Edinburgh, it seems apparent that in order to improve the air quality index, the removal or at least partial cessation of the offending causes would be a good start to go by, which have already been implemented in recent times. Introduction of low emission zones and congestion charges can go long ways in reducing the number of cars and also their concentration on the road during peak hours. The removal and replacement of wood burning stoves with more environmentally friendly powered heating devices can also cut a huge chunk out of the smoke given off by these stoves, and in combination with road-based initiatives, see results in the reduction of pollution levels in Edinburgh in the years to come.