How low cost sensors are tracking air quality in East Africa’s largest city

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Air quality sensor inside a protective plastic tube with air intake on the left.

Like many African cities, Nairobi does not regularly monitor its urban air quality, even as the levels of air pollution worsen to the point where a brown haze regularly develops over the central business district.

While Kenya has gazetted laws such as the Air Quality Regulations passed in 2014 to limit air pollution and protect the air that we breathe, there is limited information on the level of particulate air pollutants in Nairobi, and this lack of data makes it difficult to assess the potential impact…

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Newsrooms are increasingly using data in storytelling to produce better content, empower citizens and promote government accountability. But as many journalists in Africa know, accessing government data can sometimes prove to be a tall order. In some cases, the data doesn’t even exist. International organizations release periodic data on a range of issues, but what if a journalist wants to access the most recent — perhaps to-the-minute — local data?

The issue of missing data inspired the establishment of a pan-African citizen network that uses sensors to collect data for use by journalists, citizens, civic watchdogs and governments on the…

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A project that uses low-cost air quality sensors to monitor air pollution in six major African cities is providing data that journalists are using for the first time to enhance coverage of related health and environmental concerns.

Launched in 2017 in response to a lack of data on air quality in African cities, sensors.AFRICA uses locally assembled sensors to measure and record air pollutants. In turn, local news outlets have used the collected data to report on pollution levels, and community activists have used it to advocate for cleaner air.

sensors.AFRICA is a project of Code for Africa, the continent’s…

While Gigiri and Kitisuru have maintained the trees and green, leafy vegetation that once characterised the whole area, Ruaka has been stripped of this vegetation.

This uncontrolled development in the past five years has had serious consequences.

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Once a small settlement on the Nairobi-Limuru road located north-west of Nairobi, Ruaka Town has grown exponentially due in part to its proximity to the larger Nairobi metropolitan conurbation, and has become popular with city workers looking for a convenient and accessible place to live.

Ruaka is located on the border of Kiambu and Nairobi counties, at the northern end of the Northern…

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Mukurukwa Reuben slum residents have long complained of chest pains and asthma. They blame it on gas and dust emissions from a subsidiary of Bhachu Industries Limited: Accurate Steel Mills.

However, the management of Bhachu denied the allegations. Company director Gurveer Bhachu said: “I can confirm that we have all our licences, which are in accordance with international standards.” Adding: “Both Nema and City Hall are aware of our existence, what we produce and the gases we emit. This is why we furnish them with environment monitoring reports that have been approved all through.”

Bhachu said they have installed catalytic…

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Burning waste (Photo: Soila Kenya)

It all began when Elizabeth* (not real name), a four-year-old girl, moved with her family from her rural home to live in Nairobi.

A few months later, she would suffer from persistent nightly coughs occasioned by an irritable airway. Her parents took her for a medical check-up, where she was diagnosed with mild persistent asthma.

Treatment was commissioned immediately but her condition only worsened, despite being on maximal doses of medicine that she had even started reacting to with side-effects, such as jitteriness and heart palpitations.

*Elizabeth’s family lived in Industrial Area, downwind of a factory known to produce plumes…

Activists use sensor data to prove that factory is exceeding pollution guidelines

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The Star’s double-page feature article on the health impacts from factory pollution in Mukuru.

As we wait to be let into Maendeleo Learning Centre, smoke drifts over from the chimney of a factory next door. The smoke engulfs the school’s bare fields and pollutes the classrooms, where the last lesson of the day is in progress.

Whether inside or outside class, the children and teachers have no way of escaping the smoke and the white ‘dust’ particles that settle everywhere, causing a burning itch to the skin.

“What can we do? They need to finish their syllabuses before the school year ends,” a teacher says.

Oblivious to the smoke and dusk, some of the…

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By Kirah Theuri and Reshma Mawji

Up until very recently, cities in Kenya have not regularly monitored their urban air quality. Early November 2018, I flew to Kisumu — my hometown — to play a small role in changing this.

I am a technologist at Code for Africa and, as part of our sensors.AFRICA project, installed two low-cost air quality sensors to collect data on air pollution. …

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Every time I’m learning something new, one of the first things I do is go to the library. I pick up a cup of tea, find a cozy space, and start browsing the shelves. Everywhere I look, knowledge from people all over the globe comes together so that anyone can learn from the experiences, mistakes, and successes of the past.

For those of us in civic tech (creating technology for the public good), Code for All is the library that brings together the shared ideas of every civic tech team across the globe. With everything we do being ‘open source’…

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Packets of black, soot-infested air welcomed me as I stepped out of my car, blurring the sight of objects some meters away. My upper and lower eyelids fought back in embrace of each other to protect me from the peppery effect of the air as I consciously tried to separate them in order to get a good view of my new environment. The street was bold and full of life, occupied by people moving in disordered patterns with great precision and speed.

The hustle and bustle of rushed feet created a non-coherent sound as they slapped against the brown tiles…


A pan-African citizen science initiative using sensors to monitor air, water and sound pollution to give citizens actionable information about their cities.

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