Poor air quality is an increasing concern in urban areas. Government-run monitoring stations provide valuable high-quality data on the air we breathe on busy streets, but it is impossible to have them on every corner. People would also like to have the ability to track their exposure to air pollution wherever they go with portable air quality sensors.
Entrepreneurs catering to this market have started to produce low-cost air quality sensors, which are increasingly heralded as a way for governments to add to their existing network of data points and assess what difference their policies are having on the environment. However, different sensors can give different readings in the same location, even if they’re manufactured by the same provider, and the data quality can deteriorate over time.
NPL has extensive knowledge of sensors and data quality and advises government, academia, industry and the public about how to best use the data produced by air quality sensors.
NPL also validates the performance of low-cost sensors and has developed extensive facilities to test a wide range of such devices. One example is the work we do to test lower-cost ammonia sensors. Ammonia is an important pollutant that can adversely affect not only plant ecosystems, but also human health, since it can react with other chemicals to produce particulates (PM2.5). Measures to cut ammonia emissions, mainly from intensive agriculture, are believed to be the most effective way to reduce human exposure to this particulate material. NPL has tested ammonia sensors from different manufacturers in exposure chamber facilities. The results provided manufacturers with the tools to improve the traceability and accuracy of their ambient ammonia measurements, and provided end users and regulators with information about which sensors work best in which conditions.
The Royal College of Physicians has found that inhaling particulates annually causes “around 29,000 deaths in the UK, which … may rise to around 40,000 deaths when also considering nitrogen dioxide exposure.” These associated health effects have led to members of the public taking action to reduce air pollution and buying low-cost sensors to monitor air quality and their exposure to it. By providing guidance on what data from these sensors can tell us, and how that information can be used, we can ensure the public can make more informed choices about their exposure. By providing more understanding of the data, we can also help governments and industry make more informed decisions about their policies and products, to mitigate air pollution.