Pollution, an ever-looming threat to urban life, poses serious health and environmental hazards to our ecosystem. In the bustling metropolis of numerous cities, the rapid pace of industrialisation and urbanisation has inadvertently given rise to a significant increase in various forms of pollution. As citizens grapple with the repercussions of air, water, and noise pollution, there are platforms that have introduced a pollution Index as a crucial tool to assess the city's pollution levels.
To combat the escalating pollution levels, cities must implement a systematic approach to quantifying and monitoring pollution across various parameters. This is where pollution Index measures come into play. Numbeo, a platform that provides up-to-date information about the cost of living, quality of life, and various socio-economic factors across cities and countries worldwide is one such platform, and mid-way into 2023, Numbeo has updated its pollution index.
The data Numbeo provides is derived from surveys conducted by visitors to its website. Questions in these surveys are designed to be similar to many scientific and government surveys. Each entry in the survey is assigned a number within the range of -2 to +2, where -2 represents a strongly negative perception and +2 represents a strongly positive perception.
Numbeo’s index, which is continuously updated, is generated using data up to 36 months old. The platform carefully selects cities for inclusion in the index based on a minimum number of contributors to ensure statistical significance. Additionally, the semiannual index is calculated twice a year by incorporating the latest data into the historical view.
Two indexes are provided by the platform, the first is the Pollution Index which provides an estimation of overall pollution levels in cities worldwide. It considers factors such as air and water pollution, garbage disposal, cleanliness, noise and light pollution, green spaces, and comfort in relation to pollution.
The second is the Pollution Exp Scale, which uses an exponential function to show very high numbers for very polluted cities and very low numbers for unpolluted cities.
With that said, below are 10 of the most polluted cities in Africa mid-way into 2023.
| Rank | City | Country | Pollution index | Exp pollution index |
|---|---|---|---|---|
| 1. | Cairo | Egypt | 91.2 | 164.7 |
| 2. | Lagos | Nigeria | 88.9 | 158.8 |
| 3. | Marrakech | Morocco | 82.9 | 148.4 |
| 4. | Casablanca | Morocco | 82.5 | 147.5 |
| 5. | Nairobi | Kenya | 79.8 | 142.3 |
| 6. | Addis Ababa | Ethiopia | 78.6 | 138.5 |
| 7. | Alexandria | Egypt | 74.3 | 130.6 |
| 8. | Tunis | Tunisia | 71.9 | 125.7 |
| 9. | Johannesburg | South Africa | 61.3 | 106.6 |
| 10. | Pretoria | South Africa | 56.1 | 97.0 |