Monitoring Outdoor Air Quality at Your Fingertips

Photo credit: Cosmo Lo

Are you concerned about how Hong Kong’s outdoor air quality affects your health? If the answer is yes, then you may want to download an air-quality monitoring app developed by the Hong Kong University of Science and Technology when it launches in November.

“The app aims to help reduce users’ exposure to polluted air and subsequent health risks,” Professor Alexis Lau, who leads the PRAISE-HK project that develops the app, told participants at a 19 July workshop organised by Civic Exchange to test drive its prototype. PRAISE stands for Personalised Real-time Air-quality Informatics System for Exposure.

The app’s most groundbreaking feature is its ability to analyse the air quality of different outdoor environments in Hong Kong and provide forecast for up to 48 hours. Taking into account a broad range of data including different types of emissions from mainland China, building geometry, wind speed and directions, and traffic volume, the app then computes the level of air quality. The app shows an air-quality health index, different pollutant components and their associated short-term risks on people’s health.

Participants, including representatives from government departments, chambers of commerce and businesses, raised questions about the accuracy of the app’s computation, given that there are only 16 government air-quality monitoring stations across the city.

Professor Lau explained that the app uses the government data to verify its computation that combines many other factors. He said the app could be further improved when air-quality data from smart lampposts – once they are widely installed across the territory – are available and verified. The government’s plan is to install around 400 of them over the next three years.

Participants also asked about the potential benefits of the app for chronic patients. Professor Lau said by providing information on outdoor air pollution, the app could help people become more aware of the associated short-term health risks.

Hong Kong’s air quality is a topic of great public concern. There were an estimated 867 air pollution-related non-accidental premature deaths and HK$10.4 billion of direct and indirect economic losses in the first six months of 2018, according to public data from the Hedley Environmental Index, which Civic Exchange helped develop.

The app will be rolled out in three phases. Over the next year, it will include readings from indoor environments such as home, offices, schools, shopping malls and public transport vehicles to calculate an individual’s total exposure to pollutants based on the person’s travel history. By 2021, the app will incorporate data collected from the first two phases to provide personalised health alerts and recommendations. To learn more about PRAISE-HK, visit