Exposure to outdoor air pollution in Sierra Leone
Sierra Leone: Exposure to outdoor air pollution was 20.2 µg/m³ in 2024. ▼ Falling
Exposure to outdoor air pollution in Sierra Leone, 1998–2024
Source: SatPM, Atmospheric Composition Analysis Group, Washington University in St. Louis (2026) – with minor processing by Our World in Data. Measured in µg/m³.
Analysis
The most recent figure for exposure to outdoor air pollution in Sierra Leone is 20.2 µg/m³, measured in 2024.
The figure is up 10.4% on the previous year and up 6.9% over ten years.
Over the whole period, exposure to outdoor air pollution in Sierra Leone peaked at 26.2 µg/m³ in 1998 and was at its lowest, 17.9 µg/m³, in 2006.
That places Sierra Leone 84th out of 241 countries with data for 2024, putting it in the middle of the range.
The long-run direction has been consistently falling across the 27 years of available data.
Exposure to outdoor air pollution in Sierra Leone, year by year
| Year | µg/m³ | Change |
|---|---|---|
| 1998 | 26.2 µg/m³ | — |
| 1999 | 25.1 µg/m³ | -4.2% |
| 2000 | 20.7 µg/m³ | -17.5% |
| 2001 | 18.7 µg/m³ | -9.7% |
| 2002 | 19.1 µg/m³ | +2.1% |
| 2003 | 19 µg/m³ | -0.5% |
| 2004 | 21.5 µg/m³ | +13.2% |
| 2005 | 20.6 µg/m³ | -4.2% |
| 2006 | 17.9 µg/m³ | -13.1% |
| 2007 | 21.1 µg/m³ | +17.9% |
| 2008 | 21.4 µg/m³ | +1.4% |
| 2009 | 22.6 µg/m³ | +5.6% |
| 2010 | 20.9 µg/m³ | -7.5% |
| 2011 | 22.2 µg/m³ | +6.2% |
| 2012 | 19.2 µg/m³ | -13.5% |
| 2013 | 18.7 µg/m³ | -2.6% |
| 2014 | 18.9 µg/m³ | +1.1% |
| 2015 | 21.3 µg/m³ | +12.7% |
| 2016 | 19.2 µg/m³ | -9.9% |
| 2017 | 19.2 µg/m³ | +0.0% |
| 2018 | 19.8 µg/m³ | +3.1% |
| 2019 | 18.8 µg/m³ | -5.1% |
| 2020 | 18.6 µg/m³ | -1.1% |
| 2021 | 18.8 µg/m³ | +1.1% |
| 2022 | 18.5 µg/m³ | -1.6% |
| 2023 | 18.3 µg/m³ | -1.1% |
| 2024 | 20.2 µg/m³ | +10.4% |
Sierra Leone compared with similar countries
- Sierra Leone's 20.2 µg/m³ is below the median for low income countries, which is 30.8 µg/m³, 66% of the median. (25 countries reporting)
- Sierra Leone's 20.2 µg/m³ is below the median for Sub-Saharan Africa, which is 25.2 µg/m³, 80% of the median. (48 countries reporting)
Averages by decade
| Decade | Average | Lowest | Highest | Years |
|---|---|---|---|---|
| 1990s | 25.65 µg/m³ | 25.1 µg/m³ | 26.2 µg/m³ | 2 |
| 2000s | 20.26 µg/m³ | 17.9 µg/m³ | 22.6 µg/m³ | 10 |
| 2010s | 19.82 µg/m³ | 18.7 µg/m³ | 22.2 µg/m³ | 10 |
| 2020s | 18.88 µg/m³ | 18.3 µg/m³ | 20.2 µg/m³ | 5 |
Countries ranked near Sierra Leone
More environment data for Sierra Leone
- Historical exposure to drought — Land soil moisture anomaly -5.4 Percentage change (2025)
- Historical exposure to drought — Cropland soil moisture anomaly -5.39 Percentage change (2025)
- Standard Deviation, annual growth rate 0 % change on previous year (2025)
- Standard Deviation 0.232 °C (2025)
- Temperature change 1.28 °C (2025)
- Total greenhouse gas emissions excluding LULUCF (Mt CO2e), annual 1.72 % change on previous year (2024)
- Total greenhouse gas emissions excluding LULUCF (Mt CO2e), per unit 0 Mt CO2e per US$ of GDP (2024)
- Total greenhouse gas emissions excluding LULUCF (Mt CO2e), per capita 0 Mt CO2e per person (2024)
- Methane (CH4) emissions from Agriculture (Mt CO2e), annual growth rate 1.11 % change on previous year (2024)
- Methane (CH4) emissions from Agriculture (Mt CO2e), per unit of GDP 0 Mt CO2e per US$ of GDP (2024)
Frequently asked questions
- What is exposure to outdoor air pollution in Sierra Leone?
- Exposure to outdoor air pollution in Sierra Leone was 20.2 µg/m³ in 2024, according to SatPM, Atmospheric Composition Analysis Group, Washington University in St. Louis (2026) – with minor processing by Our World in Data.
- What is the highest exposure to outdoor air pollution recorded in Sierra Leone?
- The highest recorded value was 26.2 µg/m³ in 1998.
- What is the lowest exposure to outdoor air pollution recorded in Sierra Leone?
- The lowest recorded value was 17.9 µg/m³ in 2006.
- How does Sierra Leone rank for exposure to outdoor air pollution?
- Sierra Leone ranks 84th out of 241 countries with data for 2024.
- Is exposure to outdoor air pollution rising or falling in Sierra Leone?
- Over the last ten years it is up 6.9%. The long-run trend across the full record is falling.
- Where does this Sierra Leone data come from?
- The figures come from SatPM, Atmospheric Composition Analysis Group, Washington University in St. Louis (2026) – with minor processing by Our World in Data, published as part of Exposure to outdoor air pollution. Statizoid updates them automatically from the source API.
Download this data
CSV · JSON — 27 observations, free to reuse under CC BY 4.0 (Our World in Data).
About this data
Annual population-weighted average concentration of fine particulate matter (PM2.5) in the air, measured in micrograms per cubic meter (µg/m³). Fine particulate matter (PM2.5) are particles with a diameter of 2.5 micrometers or less, which can pose significant health risks.