In a recent press release, the HKUST Institute for the Environment launched a new mobile app that aims to help users reduce their exposure to outdoor air pollution.
The app is named ‘PRAISE-HK’ stands for “Personalized Real-time Air-quality Informatics System for Exposure – Hong Kong” and will help build Hong Kong into a world-class smart and healthy city. The development of the app is a five-year project which commenced in November 2016.
It covers three major release milestones for the mobile app and the system:
(1) Phase 1 – The app presented on 21 June 2019 is its phase 1 that profiles high-resolution outdoor air quality map down to street-level (with resolution down to 2-20 meter);
(2) Phase 2 – will provide full integration of personal exposure, analysing both outdoor and indoor air pollution levels including inside buildings or commuting;
(3) Phase 3 – will be an interactive app system that provides health prediction alerts based on personal responses to air pollution.
The app is a smart city app that provides state-of-the-art real-time and forecast (up to 48 hours) air quality and health risk information down to street level. It shows Air Quality Health Index (AQHI), as well as a percentage, added short-term health risk (%AR) of daily hospital admissions attributable to criteria pollutants: nitrogen dioxide (NO2), ozone (O3), particulate matter (PM10 and PM2.5), and sulphur dioxide (SO2).
The app is powered by a new system developed by cross-disciplinary experts led by the HKUST Institute for the Environment.
The high accuracy performance is attributed to the following important technologies:
(1) Air quality and atmospheric model – analyses and forecasts air quality allowing for dispersion of emissions released both regionally and in Hong Kong, and the associated complex photochemical reactions; and the influence on local pollutant dispersion of urban morphology in terms of building density and street ‘canyons’. The system generates street-scale resolution forecast maps (down to 2-20 meter) that highlight both pollution hotspots and areas of better air quality; a fusion of modelled and measured concentration data ensures forecast accuracy.
(2) Traffic model – details important road-side emission data from 30,000 Hong Kong road segments. The team developed a state-of-the-art microscopic activity-based traffic model, the first of its kind for Hong Kong, which captures the daily activity patterns of 4-million agents to derive the underlying traffic patterns across all modes of public transport as well as private car usage. The model produces detailed dynamic traffic patterns which are then used to estimate roadside emissions.
(3) Sensor technologies – developed with sophisticated hardware design and an algorithm to reach the competent performance goals, and to fit the need for complicated microenvironment monitoring.
(4) Big data – fill a wide range of data gaps (from changing traffic speeds to special traffic incidents) to improve overall accuracy and to raise real-time performances;
(5) Air quality exposure science – evaluates personal exposure profiles and associated health impacts; and
(6) Mobile technology – identifies users’ location either outdoor or indoor, in what kinds of buildings or transportation modes, so that PRAISE-HK system can analyse its personal exposure to the surrounding air quality.
Users can access this useful information on the PRAISE-HK app and take the corresponding action, in particular, to reduce short-term exposure risks that make a big difference for people who are sensitive to air pollution.
Hong Kong’s air pollution problem has improved significantly over the last few years but is still far from meeting the global. The region’s official air quality monitoring network, limited to 16 fixed-site stations, is designed to measure the average air quality over different districts, but they cannot show the fine scale street-to-street air quality variations. This may give a false impression that there is a little variation in air quality across the city and that there is not much the public can do to avoid highly polluted areas.
In fact, as a result of different traffic and urban ventilation conditions, the air quality can vary widely from one street to another in dense urban cities like Hong Kong. The PRAISE-HK app maps air quality variation down to individual streets, allowing users to proactively plan their time and activities and reducing exposure from high pollution.
People were previously helpless when the issue of air pollution was first discussed. However, with the new technology, this is expected to change. By empowering the public with personalized air quality information, it is believed that the app can lead to a perception change in air pollution exposure, and can also drive behavioural change in the public.
Now that the Artificial Intelligence era has been entered, it is now possible to combine innovations and new technologies to solutions for smarter and healthier lifestyles.