Low-Cost Sensors Could Help Monitor Air Pollution

They are particularly useful in the developing world

  • Ugandan researchers have developed inexpensive air quality monitoring sensors to help keep people healthier. 
  • The AirQo air quality monitoring project, partly funded by Google, uses a network of sensors that cost $150 apiece. 
  • Globally, air pollution causes more deaths than any other environmental hazard.
An arial view of building in Cape Town, South Africa, showing pollution over the city.

Jorg Bahl / EyeEm / Getty Images

Air pollution is worsening around the world, but keeping track of just how bad it is on a daily basis can involve expensive equipment. 

Ugandan researchers have developed inexpensive air quality monitoring sensors that work in extreme conditions. The sensors could let Uganda and other countries switch from pricey imported monitors. It's part of a growing effort to develop a broader network of air quality monitors. 

"Many individuals in developing countries are unable to afford even low-cost air quality monitors and are thus unable to determine air pollution levels in their neighborhood," Akshaya Jah, a professor of economics and public policy at Carnegie Mellon University, told Lifewire in an email interview. "Local policymakers in developing countries may be unable to deploy EPA-grade monitors at scale, requiring lower-cost air quality monitors with similar levels of precision in measurement."

Keeping Track of the Air

Scientists at the Makerere University in Kampala designed and built the AirQo air quality monitoring project, partly funded by Google. The system uses a network of sensors, which cost $150 each, to gather air quality data around Kampala. Data from the monitors is processed by artificial intelligence and made available to the public via a smartphone app.

Kampala suffers from high levels of air pollution, and the city was using imported air quality monitors that cost $30,000 each and broke down often. The AirQo's monitoring devices are so inexpensive that they can be installed in many parts of the city and are designed to withstand high levels of dust and heat. A recent study found that outdoor air pollution is increasing across Africa. 

"Without air quality data, decision-makers from parents right through to the Government do not have the information to know the extent of the problem, take appropriate action, or measure the success of any action," Engineer Bainomugisha, the project lead of AirQo, said in a news release. "We believe that the first step in being able to improve air quality is to be able to measure it, know what the current air pollution levels are, its causes, and most importantly, its consequences to our health and the environment. The AirQo project fills in this gap by creating low-cost air pollution monitoring devices designed to work in the unique contexts of African cities." 

Growing Need to Monitor the Air

According to the WHO, air pollution causes more deaths than any other environmental hazard. While lower-cost sensors are generally not as accurate as the high-cost equipment used in the Global North, they can provide critical measurements in places where there is otherwise no data, Albert Presto, a research professor in the Department of Mechanical Engineering at Carnegie Mellon University, said via email. 

"Many countries in Africa have very few, or even zero, air quality monitors," Presto added. "In those cases, the low-cost sensors can provide important data to start quantifying how dirty the air is."

Todd Richmond, a professor at Pardee RAND Graduate School and an IEEE member, told Lifewire in an email that many toxins and pollutants are invisible to the naked eye, so dedicated sensors are necessary to monitor air quality.

"If you don't know there is a problem, then you can't try and solve it," he added. "Having a robust and ubiquitous air monitoring system is critical for understanding risks, both current and future, and giving the necessary data to explore causes and effects. Think of low-cost air quality sensors as a neighborhood watch for your lungs."

A young person in a city wearing a breathing mask to protect against air pollution.

Micrgen Images / Science Photo Library / Getty Images

The new sensors in Africa are only one of many efforts worldwide to create lower-cost air sensors, some of which are intended to be used in your home. Plume Labs, for example, has developed a personal pollution monitor called Flow. 

"Our focus at Plume Labs is to provide actionable air quality information to people when they need it the most," Tyler Knowlton, air quality expert at Plume Labs, said in an email. "To this, we must also understand indoor air pollution levels as well as outdoors. In our experience, low-cost sensors are the key."

Plume worked to make its Flow monitor as small and inexpensive as possible. The system integrates many pieces of data and maps the results using artificial intelligence. 

"We can now provide highly detailed air pollution maps for parts of the world that have been virtual data black holes," Knowlton said. "We create these maps and the underlying data with very few monitors and can then enhance them significantly using low-cost sensors."

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