Air pollution remains a global challenge with deep local consequences. The World Health Organization (WHO) estimates that air pollution causes around seven million deaths annually, with most of the burden of premature deaths falling on low- and middle-income countries (LMICs). Viet Nam is no exception. Urban air quality is an ongoing concern in the country, with cities like Hanoi and Ho Chi Minh city frequently exceeding WHO’s recommended levels for particulate matter (PM2.5) in recent years. In 2024, Hanoi ranked 7th out of 121 global capitals in average annual PM2.5 concentrations, placing it among the world’s most polluted capitals. Yet, the monitoring network is still limited, and more monitoring stations are needed to support the government reduce pollution effectively.

To address these challenges, the Government of Viet Nam issued a key resolution in 2025, calling for urgent action to reduce air pollution in major cities. This has been reinforced by comprehensive instructions from Deputy Prime Minister Mr Tran Hong Ha, who emphasized the need for breakthroughs in air quality management, particularly in strengthening monitoring at both national and local levels. This local-level monitoring allows for the identification of pollution hotspots, development of targeted mitigation measures, and protection of public health.

At the same time, localized air quality monitoring is vital for communities. Providing local citizens with access to local and hyperlocal monitoring allows for real-time information about the air they are breathing in the places that matter most: their homes, schools, universities, workplaces, and neighbourhoods.

However, despite growing awareness, access to reliable, hyperlocal data remains limited, especially outside major urban centres. This is where decentralised, low-cost, and open-source tools have the potential to make a difference by equipping local communities with the tools and capacity to monitor general indicators of air quality themselves, and in doing so, to inspire more informed choices and stronger advocacy for clean air. Greater information on such air quality also improves public awareness on the importance of good air quality, the health issues posed by air pollutants and the need for coordinated efforts from all stakeholders to join in on the fight against air pollution.

Toolkit to Trial – A Pilot Took Shape

The UNDP Global Centre, Singapore, hosted the Open Innovation Platform Challenge to design a Low-Cost Hyperlocal Air Quality Monitoring Toolkit in collaboration with the Ministry of Sustainability and the Environment, and the National Environment Agency, on the Infocomm and Media Development Authority Pixel platform. The challenge, spanning from August to September 2024, aimed to identify scalable, community-empowering technologies for low-cost air quality monitoring. Following the challenge, the Centre awarded AirGradient the winner as their proposal aligned with UNDP’s vision, and their open-source, low-cost, and sustainable focus. Together, UNDP and AirGradient partnered to co-develop a Toolkit – a step-by-step, open-access guide to planning, setting up, and operating a community air monitoring network.

From June to September 2025, the pilot was developed in Viet Nam with a multi-fold purpose:

• Testing the functionality of the sensors and Toolkit in real-world conditions
• Building local capacity by engaging students
• Generating hyperlocal data to spark curiosity, potential for research, and inform local actions

Learnings and Insights from the Pilot

A defining feature and strength of the pilot was the active involvement of users, primarily local university students. A total of 16 sensors were installed across Hanoi and surrounding areas, at both outdoor and indoor venues. The sensors were located in high-density urban districts such as Thanh Xuan, Dong Da, and Cau Giay, and in less dense sub-urban or rural areas such as Gia Lam and Ba Vi (sensors L3, L5, and L10 on the map below), creating a diverse testing environment.