Pollution level: 216 ug/m3
It might seem strange that a country with a population of only 2 million people, and the largest proportion of land under conservation in the world, is the second most polluted nation in the world. But, that is the case of Botswana, 80 percent of which is covered by the Kalahari Desert.
The country was one of the poorest nations in Africa at the time of its independence from Britain in 1966. Today, Botswana is one of the world’s fastest growing economies, and the largest producer of diamonds. The country has transformed itself into a middle-income economy with an annual average growth rate of about 9 percent, according to The World Bank. Mineral revenues account for about 40 percent of government revenues.
With growing wealth, the southern African nation has experienced widespread environmental damage. Wild fires and pollution from the mineral industry are the main sources of the country’s poor air quality. Copper smelting for example has been blamed for sulfur dioxide and nickel emissions.