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Air pollution threatens the lives of millions each year. It is now considered to be the largest threat to human health globally. Exposure to air pollution exacerbates a wide range of diseases, including asthma, different types of cancers, heart disease, acute respiratory infections, and pulmonary illnesses. The World Health Organization (WHO) estimates that 91% of the world’s population breathe air that exceeds WHO guideline limits, demonstrating the urgent need to reduce air pollution to limit the vast number of unnecessary deaths (4.2 million annually) caused by exposure to high levels of pollutants.
Newly developing sensor technology could make air pollution monitoring more accessible and may be vital in accelerating much-needed reductions in air pollution. Below, we discuss new developments for detecting air pollution in cities with the use of sensors.
Monitoring Via Sensors is Key Strategy Reduce Air Pollution
Collecting and sharing air pollution levels in real-time offers experts an opportunity to better understand the nature of air pollution and make meaningful changes to improve air quality in cities, particularly those that struggle with traffic levels. Sensors can highlight the times of day and areas of the city where air pollution is highest. This can guide strategy makers to target the worst-hit locations and implement problem-solving to reduce the cause of the elevated pollution.
Air pollution sensors have become increasingly popular over recent years. A range of sensors is currently available that accurately measure levels of air pollution. Many of these air sensors are connected, opening the opportunity to use the internet of things (IoT) to automate traffic management systems and other pollution reduction strategies in response to rising pollution levels.
Therefore, sensors offer a route to simplifying air pollution reduction as technology improves. They are becoming more accessible and cheaper than ever, making the widespread adoption of sensors more plausible.
Numerous innovative sensors have recently entered the market, from sensors installed on electric scooters and other modes of transport to simple, portable sensors that anyone can place outside their window. Here, we discuss these different types of sensors and evaluate how they will evolve in the future to tackle air pollution in cities.
Innovations in Air Pollution Sensors
There are four main types of sensors that have been developed to measure air quality. Reference sensors, also referred to as conventional air quality monitoring sensors, portable sensors, passive diffusion tubes for gaseous pollutants, and newer digital or low-cost sensors (LCS).
In terms of monitoring air pollution city-wide, the newer digital sensors show the most promise. They are smaller than the other types of sensor, more compact, cheaper to make, simpler to run, and produce high-resolution spatiotemporal data relating to air pollutant concentrations. They have the opportunity to gather and communicate high-quality data that spans the entire city if installed at appropriate locations. Their digital nature allows them to connect, giving experts a clear view of the dynamic air pollution changes that occur daily. The fine-grain data can even allude to pollution causes beyond surges in traffic by using analytical tools to study connections with other data sets, such as weather or behavioral data.
The benefits of digital sensors have led scientists to investigate the most effective ways to position them to gain insightful data.
E-scooter operator Voi is working on a pollution-sensing e-scooter, which is due for commercial release in early 2022. The e-scooter, named Voiager 4, has smart sensors incorporated into the vehicle and alerts riders as to which routes may expose them to higher levels of air pollution. The innovation is simple, but it allows users to make significant changes that protect them from air pollution. Over time, the use of such a system could significantly reduce the negative impact of air pollution on a city's residents. Further to this, the scooter’s data can be shared with cities to guide their traffic management systems to reduce pollution levels.
Similarly, a project in Sweden has focussed on investigating the benefits of real-time air pollution monitoring. The project, known as GreenIoT was established to explore how the IoT can measure air quality in the city of Uppsala.
The researchers installed wireless sensors onto Uppsala buses and integrated them with a mobile sensor network. The team in Sweden recently published the findings of this stage of the project, demonstrating that data could be delivered to the 4G network at a success rate of up to 100%. The team is planning more studies to evaluate sensor data quality.
The Future of Air Pollution Sensors
Many cities around the world have adopted the use of pollution sensors to address air pollution. It is likely that over the coming years, sensors will become more commonplace, with cities implementing innovative strategies such as installing sensors onto public transport to help protect residents from the harmful effects of air pollution exposure.
References and Further Reading
Air pollution. World Health Organization. Available at: https://www.who.int/health-topics/air-pollution#tab=tab_1
Air pollution and health. The United Nations Economic Commission for Europe (UNECE). Available at: https://unece.org/air-pollution-and-health
Kaivonen, S. and Ngai, E., 2020. Real-time air pollution monitoring with sensors on city bus. Digital Communications and Networks, 6(1), pp.23-30. https://www.sciencedirect.com/science/article/pii/S2352864818302475
Pollution sensors on e-scooters could help cities monitor air quality. Tom Stone. Traffic Technology Today. Available at: https://www.traffictechnologytoday.com/news/multimodal-systems/pollution-sensors-on-e-scooters-could-help-cities-monitor-air-quality.html
Toma, C., Alexandru, A., Popa, M. and Zamfiroiu, A., 2019. IoT Solution for Smart Cities’ Pollution Monitoring and the Security Challenges. Sensors, 19(15), p.3401. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6696184/