It’s a shocking statistic, and nowhere is that more apparent than the Egyptian capital, Cairo. With the eyes of the world on the country as it hosts COP27, Egyptians don’t have to look far for the devastating effects of pollution.

This greater area of this sprawling metropolis is home to 21 million people, one of the biggest cities in Africa. For years though, its residents have been breathing air that contains high levels of some of the most poisonous pollution particles.

The government admits two million people seek treatment nationwide for respiratory problems caused by bad air, with the World Bank saying there are around 2,600 premature deaths in Cairo alone annually because of it.

You certainly notice it as soon as you step out of your door.

In several neighbourhoods in the city, you can feel the soot at the back of your throat, and you feel conscious of the taste of the air. On several occasions, despite the heat, I found myself sneezing, a visceral reminder of the fumes around me.

The city's streets are a constant throng of congestion, with vehicles, some modern, others battered relics of the 70s and 80s, battling their way through the traffic. They are not the only cause of the problem though. Cairo is heavily industrialised and also sits in a valley, which can trap bad air. Sand and desert dust can also add to the air pollution.

Authorities here know there is a problem. An official from the Ministry of Environment tells me that tackling air pollution is one of their main priorities, and that they have introduced 116 air monitoring stations across the country.

One of the main factors of the issue used to be farmers burning rice straw at the end of their harvest, which would create an annual black cloud over the city. This has now been mainly stopped and recycling encouraged.

Someone looking upwards for a solution to the problem is 18-year-old Maha Abdalla Ahmed.

I meet her on the roof of a dilapidated block of apartments in a working class part of the Arab al-Maadi district. It’s a maze of crumbling buildings, with the sounds of traffic and crowing cockerels filling the air. I can taste the dust and pollution as we speak.

She and her friend are using these rice husks as a compost to place plants and foliage on the flat roofs of buildings across Cairo. She tells me that for every one square metre she plants, it removes 100 grammes of pollutants a year.

When I ask if she is worried for the future of the planet, a concerned look crosses her face. "Of course I am. We need to start applying the sustainable development goals so that we can have a sustainable and green planet. Everyone can make a difference."

There is no doubt that the lungs of the city are choking, but with schemes like Maha’s and governmental action, the residents of Cairo will be hoping it’s not too late to save their hometown’s environment.