Air quality in Sarajevo

What is the air quality level in Sarajevo?

Sarajevo is the capital city of Bosnia and Herzegovina, also being the largest city within the country, home to over 275 thousand inhabitants, with more than half a million people also living within the surrounding metropolitan areas. Sarajevo is subject to some particularly bad levels of air quality, having numerous different causes of air pollution that are compounded further by other factors. In April of 2021 it was seen with a US AQI reading of 105, a considerably high number that placed it in the upper echelons of the worlds most polluted cities at that particular time of the year.

This US AQI number of 105 also placed it into the ‘unhealthy for sensitive groups’ bracket, which indicates that the air quality would be hazardous for much of the population, with certain demographics being even more at risk. These would include young children, pregnant mothers and the elderly, among other groups such as those with compromised immune systems or pre-existing illnesses.

Looking at the data gathered over the course of 2020 for further reference, Sarajevo came in with a PM2.5 reading of 42.5 μg/m³, an extremely high number for its yearly average, putting it once again into the higher end of the unhealthy for sensitive groups bracket, which requires a PM2.5 reading of anywhere between 35.5 to 55.4 μg/m³ to be classified as such. PM2.5 refers to tiny particulate matter that is 2.5 micrometers or less in diameter, roughly 30% the size of a human hair. Due to this extremely small size and the danger it presents to human health, it is one of the major components used in the calculation of US AQI, or the US air quality index.

This reading of 42.5 μg/m³ placed Sarajevo in 167^th place out of all cities ranked worldwide over 2020, and has been shown to have actually gotten worse in regards to its air quality, with previous years coming in with lower readings such as 34.1 μg/m³ in 2019, and 38.4 μg/m³ in 2018. As such, Sarajevo is a city that has many steps ahead of it to take in order to improve the condition of its air, currently being hazardous for those who are subject to breathing its air, particularly if these higher concentrations are respired over long periods of time.

What are some causes of polluted air in Sarajevo?

Due to its geographical location of being within a deep valley, surrounded by even higher mountains, historically Sarajevo has always been subject to less than appreciable levels of air quality, due to the pollution generated by anthropogenic activity being trapped within this sink, lacking the necessary wind strength to blow much of its air contaminants away. Strong winds are one of the more important factors when it comes to removing pollution from a city’s limits, having far more potency than heavy rain in cleaning the air of both fine (PM2.5) and coarse (PM10) particles, as well as other chemical pollutants.

In regards to its modern causes of pollution, Sarajevo has many sources of combustion occurring, with ones such as the use of firewood and charcoal within homes being a prominent issue, causing large amounts of soot and chemicals to be released into the air, particularly during the colder months when the temperatures drop.

As well as this, old or outdated vehicles are still utilized within the city, something that can cause excessive amounts of vehicular exhaust smoke to build up. These older motors can also leak larger amounts of oil vapor and other hazardous chemicals, due to the poor combustion process that old vehicles often present with.

Freight vehicles, or heavy duty one such as trucks and lorries can also contribute to this problem, putting out large amounts of their own noxious exhaust due to often running on fossil fuels such as diesel. Factories, power plants, and even construction sites. Poorly maintained construction areas can release huge amounts of finely ground dust that can cause irreversible damage to the lungs of those who inhale it, and with all these factors combined together, Sarajevo subsequently has its extremely poor placing on the world circuit.

What are the main types of pollution in Sarajevo?

With the previously mentioned pollution sources in mind, they would release large amounts of certain air contaminants. These would be ones such as nitrogen dioxide (NO₂), as well as sulfur dioxide (SO₂). Ozone (O₃) would also be present on ground level, presenting a significant danger to those who are exposed.

Other pollutants include ones such as black carbon (the main component of soot), as well as volatile organic compounds (VOCs), and in the case of construction site pollution, silica dust, gravel particles and even heavy metals such as lead and mercury. Some examples of VOCs include chemicals such as benzene and formaldehyde.

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

Observing the data collected over the course of 2020, there are several months that stand out as having severe levels of air pollution, as well as an extended part of the year that has moderate (but still unsafe) levels of PM2.5 on record. The end of the year is when the air quality takes a turn for the worst, with Septembers reading of 15.4 μg/m³ rapidly rising to 25.2 μg/m³ in October, and then up even more to 78 μg/m³ and 80 μg/m³ in November and December respectively.

January had the absolute highest reading with a massive 181.8 μg/m³ being on record, putting it within the ‘very unhealthy’ group rating (150 to 250.4 μg/m³ required for classification). This is a number that would indicate that the air is absolutely permeated with soot, haze, dust clouds and all manner of toxic chemical pollutants.

The readings taken over November and December would also place those two months within the ‘unhealthy’ ratings bracket, indicating that the very end and beginning of the year would be the most polluted time period in Sarajevo.

When is the air quality at its cleanest in Sarajevo?

In contrast to the extremes of pollution seen in the city, it did have some months with more appreciable air quality levels, with one month even falling within the World Health Organizations (WHO's) target goal for the best quality of air at 10 μg/m³ or less.

The months of May through to September had the lowest levels of PM2.5, with readings of 13.8 μg/m³, 9.5 μg/m³, 14 μg/m³, 15.2 μg/m³ and 15.4 μg/m³ present. This indicates that July was the cleanest month of the year, being under 10 μg/m³, with its surrounding months having decent levels of air quality, falling into the lower end of the ‘moderate’ pollution bracket (12.1 to 35.4 μg/m³ required).