Air quality in Scotland

How clean is Scotland's air?

Scotland air quality ranks among some of the least polluted within the United Kingdom, but air pollution remains a significant health hazard causing thousands of premature deaths per year, and often exceeds both Scotland’s and the European Union’s legal limits. The main pollutants of concern within Scotland are particulate matter (microscopic airborne particles with a diameter less than 10 microns, also known as PM10 or PM2.5), and nitrogen dioxide (NO₂). Health issues caused by air pollution in Scotland can include the development or aggravation of respiratory diseases such as asthma and bronchitis, in addition to heart disease, stroke, and cancer. Certain groups of the population are more vulnerable to the impacts of Scotland air pollution, such as children (whose lung development may be stunted), the elderly, lower income communities and people with pre-existing health conditions.¹

While Scotland’s air quality is generally found to be cleaner than that of its neighbour England, the nation-state Scotland’s air pollution is estimated to contribute toward 2,500-3,500 premature deaths annually, based on research by the Royal College of Physicians.² Scotland’s levels of PM2.5 mostly achieve both the Scottish and World Health Organisation (WHO)’s target limit of annual PM2.5 concentration below 10 µg/m³, with the exception of the village of Munlochy. According to IQAir’s 2019 World Air Quality Report, Munlochy was found to have the worst levels of PM2.5 air pollution in Scotland in 2019, with an annual average concentration of 10.7 µg/m³.³ All other Scottish locations with available data scored an annual average PM2.5 level between 4.9 to 8.2 µg/m³, with Stirling emerging as Scotland’s cleanest city for PM2.5 pollution during 2019. However, despite most Scottish locations achieving the WHO target for PM2.5, it should be noted that the WHO emphasizes there is no known “safe” limit for exposure to particulate pollution, below which no health impacts may be observed.

Alternatively, numerous locations within Scotland are found to breach both the Scottish, UK and EU’s shared annual average target limit concentration for nitrogen dioxide of 40 µg/m³. During 2019, seven streets were recorded as having annual average NO₂ levels exceeding 40 µg/m³. These were: Glasgow’s Hope Street (55.6 µg/m³); Nicolson Street in Edinburgh (48.8 µg/m³); Seagate in Dundee (43.9 µg/m³); Academy Street in Inverness (43.3 µg/m³); Lochee Road in Dundee (42.5 µg/m³); and St John’s Road in Edinburgh (41.9 µg/m³).⁴ NO₂ pollution in Scotland is emitted largely from fuel combustion in road transport, particularly diesel; as well as power stations and domestic heating. ⁵

A real-time ranking of the cleanest and most polluted locations by Scotland AQI can be viewed at the top of this page, along with a live Scotland air quality forecast within each location’s page.

What is Scotland doing about air pollution?

Scotland manages its air quality in collaboration with the UK’s Department for Environment, Food and Rural Affairs (DEFRA) in order to achieve the United Kingdom’s air quality targets as a whole, in line with both the UK and European Union’s environmental legislation. However, as one of the UK’s devolved administrations (along with Wales and Northern Ireland), the Scottish government also governs their air quality management system with some independence. For example, while the majority of the UK follows the EU’s target limits for PM2.5 and PM10 (annual average concentration limits below 25 µg/m³ and 50 µg/m³, respectively), in 2016 the Scottish government became the first in Europe to implement the WHO’s much stricter standard for PM2.5 (annual average below 10 µg/m³), and also adheres to an even stricter annual guideline than the WHO for PM10, of below 18 µg/m³ (the WHO’s annual average target for PM10 is 20 µg/m³).⁶

As part of Scotland’s independent management of domestic air quality, in November 2015 the Scottish government launched their first independent Cleaner Air For Scotland (CAFS) strategy, with the ambition to achieve the best air quality within Europe.⁷ In addition to incorporating the WHO’s limit for PM2.5 into Scottish legislation, some key goals of the CAFS include to raise public awareness of air pollution, develop a National Modelling Framework, and a National Low Emission Framework. In 2018, Scotland introduced its first Low-Emission Zone (LEZ) in Glasgow. The LEZ imposes a minimum environmental standard for vehicles entering a specific zone, and vehicles that do not comply with the minimum emission standard are fined a penalty. This aims to reduce the number of high-polluting vehicles within key areas, and ultimately reduce people’s exposure to air pollution. Further LEZ’s are planned for Scotland’s three other largest cities during 2021: Edinburgh, Aberdeen and Dundee. ⁸

The Scottish government reports a Scotland Air Quality Index using the UK’s ‘Daily Air Quality Index’ system, which communicates overall air quality on a scale of 1 (Low) to 10 (Very High). Live readings from Scotland’s network of sensors can be viewed above in the Scotland air quality map.

Is Glasgow polluted?

Glasgow is home to Scotland’s most polluted street for NO₂ levels, which has repeatedly breached the Scottish, UK and EU air quality standards for several years in a row. Hope Street, in Glasgow’s city centre, has been Scotland’s most polluted street every year between 2017-2019, while it has breached the Scottish annual target for NO₂ levels (40 µg/m³) consistently since 2012.⁹

To tackle the high levels of Glasgow air pollution, Scotland’s first Low-Emission Zone (LEZ) was introduced in Glasgow’s city centre in 2018. While Glasgow’s LEZ is forcing some of Glasgow’s bus fleet to lower their emissions in order to retain access to the city centre, campaigners suggest that improvements are not happening fast enough.⁴

With an annual average concentration of 7.1 µg/m³, Glasgow is Scotland’s most polluted city for PM2.5 pollution, according to IQAir’s 2019 World Air Quality Report; although it ranks as Scotland’s 12th most polluted location out of a total of 33, the eleven locations with higher PM2.5 levels are towns and villages. Scotland’s other major cities with a population above 100,000 residents averaged a slightly lower level of annual PM2.5 during 2019, with Aberdeen following closely with 7.0 µg/m³; Edinburgh air pollution with 6.6 µg/m³; and Dundee with 6.2 µg/m³.³

What are the main causes of air pollution in Scotland?

The major sources of air pollution in Scotland include emissions from transportation, ammonia emissions from fertilizers used in agriculture, and emissions from domestic heating.¹⁰

Where is the best air quality in the UK?

In general, the majority of locations with the cleanest levels of UK air quality are found within Scotland. Out of 130 cities included in IQAir’s 2019 World Air Quality Report, 32 out of the 46 cleanest cities measured for PM2.5 pollution are based in Scotland. While the UK’s average national PM2.5 level was 10.5 µg/m³, the average PM2.5 level for Scottish locations was a much lower 6.9 µg/m³*. However, despite Scottish locations filling many of the cleanest spots within the UK’s cleanest cities ranking, the location with the best air quality in the UK for PM2.5 in 2019 was the English village of Harmondsworth, with an annual average concentration of 4.3 µg/m³.

*The UK national average is calculated weighted by city population; the Scottish average is calculated on a city basis with no weighting applied.

+ Article resources

[1] Friends of the Earth Scotland. “Air Pollution”, Friends of the Earth Scotland website, n.d.
[2] Friends of the Earth Scotland. “New Research Means 2500 Deaths a Year in Scotland are from Air Pollution”, Friends of the Earth Scotland website, February 23, 2016.
[3] IQAir. “2019 World Air Quality Report”, IQAir website, March 18, 2020.
[4] Gavin Thomson. “Scotland’s Most Polluted Streets”, Friends of the Earth Scotland website, January 19, 2020.
[5] Scottish Parliament. “SPICe Air Pollution Briefing: Air Quality In Scotland”, Scottish Parliament website, May 10, 2016.
[6] Air Quality in Scotland. “Air Quality Standards and Objectives”, Air Quality In Scotland website, n.d.
[7] Scottish Government. “Cleaner Air For Scotland: Road to a Healthier Future. Annual Progress Report 2016”, Scottish Government website, June 15, 2017.
[8] Libby Brooks. “Plan to cut Glasgow air pollution is a failure, say campaigners”, The Guardian, March 16, 2018.
[9] Gary Armstrong. “Why is Hope Street the most polluted street in Scotland and what’s being done about it?”, Glasgow Live, January 22, 2020.
[10] Scottish Government. “Cleaner Air for Scotland”, Scottish government website, August 29, 2019.