Expanding Air Quality Monitoring with Low Cost Sensors: What Policymakers and Practitioners Need to Know

6 March 2026

The UN Environment Programme’s Global Environment Outlook 7 (GEO‑7) warns that “globally, six out of the top ten countries with the worst air pollution levels are from Asia and the Pacific, leading to respiratory diseases, poor health and lower agricultural productivity”. Against this global backdrop, EANET’s two new publications offer region‑specific guidance to help countries deploy Hybrid Air Quality Monitoring Networks (HAQMN) that combine reference‑grade monitors with Low‑Cost Sensors (LCS).

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Guidelines for Establishing a Hybrid Air Quality Monitoring Network – Strategic direction for policymakers and planners

While reference-grade monitors have been traditionally used for air quality monitoring, based on their reliability and high accuracy, they also require a high investment and strong technical operation knowledge. Sensors refered to as ‘Low-Cost Sensors’ (LCS), on the other hand, have appeared in the recent years with improved technology related to the size and energy efficiency, lower cost and easier deployment, in particular in zones with limited infrastructures. However, LCS lack the same measurement precision and require maintenance and data analysis. The complementary use of LCSs and reference-grade monitors is referred to as Hybrid Air Quality Monitoring with Low-Cost Sensors (HAQMN), as described in these EANET Guidelines.

The Hybrid Air Quality Monitoring with Low-Cost Sensors Guidelines provide governments with a strategic framework for integrating LCS into existing reference‑grade networks. They emphasize that LCS should supplement, not replace,  reference-grade monitors, ensuring expanded coverage without compromising accuracy. They also lay out critical principles such as robust Quality Assurance and Quality Control practices, contextualized network planning, and clear differentiation from the EANET’s traditional monitoring practices and guidelines.

Aimed at senior government officials, these Guidelines describe institutional responsibilities, site selection criteria, and governance considerations. They serve as supporting documents to the EANET’s existing technical manuals, helping countries in the region and beyond expand monitoring capacity methodically and consistently.

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Technical Manual for Hybrid Air Quality Monitoring with Low‑Cost Sensors – Operational guidance for technicians and practitioners

The Technical Manual provides detailed, operational instructions for implementing and maintaining LCS within hybrid networks. It includes step‑by‑step procedures for LCS assembly, installation, calibration, site preparation, communication systems, maintenance, and safety.

The document also incorporates expanded Quality Assurance and Quality Control procedures—such as data screening, bias correction, and performance evaluation—reflecting technical revisions made after expert review. It is designed for technicians, field operators, and analysts responsible for ensuring high‑quality, reliable data.

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How the Two Reports Work Together

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A Regional Response to a Global Environmental Warning

Together, EANET’s Hybrid Air Quality Monitoring Guidelines and Technical Manual form a comprehensive, region‑tailored toolkit that intend to help countries modernize their monitoring systems, strengthen data quality, and better protect public health.

Adopted by the Twenty-seventh Intergovernmental Meeting on the EANET in November 2025, both publications reflect the increased interest to intergrate the use of new technologies for air quality monitoring in the EANET countries, in line with the EANET’s recently launched Medium-Term Plan (2026-2030).

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Read the Guidelines for Establishing Hybrid Air Quality Monitoring Network (HAQMN) in the EANET region

Read the Technical Manual for Hybrid Air Quality Monitoring with Low-Cost Sensors: Implementation Guidelines in EANET

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Photo credits: Ho Chi Minh by Andrei Miranchuk (2019).

EANET Training on Air Quality Monitoring Systems Using Low-Cost Sensors

19 October 2023 – Bangkok, Thailand

The EANET Training on Air Quality Monitoring Systems Using Low­-Cost Sensors took place on 6 and 7 September 2023, in Hanoi, Viet Nam, and online. The event was jointly organized by the ADB, the Network Center for the EANET, and the Vietnam Institute of Meteorology, Hydrology, and Climate Change (IMHEN) and gathered 100 participants, online and in person, from the EANET Participating Countries and beyond, to learn about LCS equipment operation, quality assurance, data accuracy, early problem detection, and effective use of monitoring data.

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Opening Session

Ms. Karma Yangzom, Principal Environment Specialist at the Asian Development Bank (ADB), delivered Opening Remarks expressing gratitude for joining the Vietnam project with IMHEN. She highlighted the significance of the hybrid method in addressing monitoring resource constraints, emphasizing the need for meticulous use of LCS to ensure sensor functionality and data verification, emphasizing the importance of high-quality, verified data, and underlining the workshop’s objective to research proper LCS utilization while expressing appreciation to EANET for hosting the workshop with hopes of providing valuable information to participants.

Dr. Le Ngoc Cau, the Director of the Center of Environmental Research at the Vietnam Institute of Meteorology, Hydrology, and Climate Change (IMHEN), expressed gratitude to the Asia Center for Air Pollution Research, ACAP (the Network Center for the EANET) and ADB for their support in the project to establish an air quality system, highlighting the costliness of such systems in urban areas and the potential of LCS as a more affordable alternative if data accuracy can be ensured. The LCS has been installed in two provinces in Vietnam as part of the project, providing participants with a deeper understanding of its capabilities, and he thanked all the participants and EANET for organizing the workshop.

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Introduction to the use of Low-Cost Sensors in Vietnam and in other Asian Countries

Dr. Le Ngoc Cau delivered a presentation on IMHEN’s role, its air quality monitoring system, air quality modeling, and EANET activities in Vietnam. He highlighted the installation of a PM2.5 monitor in Hoa Binh station in 2015 and the collaborative installation of LCS at the same station with the Network Center. Dr. Cau emphasized the importance of verifying LCS data for reliability and the need to figure out how to integrate LCS and conventional monitoring data. They expressed interest in further collaboration with international organizations.

Ms. Karma Yangzom shared experiences from Asian countries regarding the use of Air Quality sensors in ADB projects aimed at enhancing awareness and efforts to improve air quality. She highlighted the stability of AQ Mesh sensors, which only require sensor replacements every two years, and emphasized the use of LCS to present air quality information to the public. She highlighted the importance of ensuring the reliability of the data generated from the LCS.

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EANET Projects on LCS Technical studies

Dr. Akie Yuba, a Senior Researcher from ACAP, provided a report on LCS technical studies in Vietnam and Myanmar, which were carried out as part of EANET Project Activities. In Hoa Binh, Vietnam, five LCS units were installed, with a specific focus on PM2.5 and other parameters. In Yangon, Myanmar, LCS units, specifically GBiot and Haz Scanner, were utilized for monitoring PM2.5, O3, NO2, and meteorological data during both monsoon and non-monsoon seasons. A good correlation was observed in the data, though different values were displayed in the slopes, emphasizing the need for blackout preparedness to prevent electricity voltage fluctuations.

Dr. Hiroaki Minoura, a Guest Researcher at ACAP demonstrated, along with Dr. Yuba, how to install an LCS, how to initiate it, to connect it to a data server, and how to retrieve LCS data when there are data communication issues.

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Dr. Kazuhiro Misaka, Director of Green Blue Corporation, a private company specializing in the inspection, and maintenance of environmental monitoring and measurement equipment, delivered a presentation on data screening and analysis obtained with LCS and the Hybrid Air Quality Monitoring Network (HAQMN), accompanied by Dr. Akie Yuba and Dr. Hiroaki Minoura. Dr. Misaka explained the process of screening raw LCS data and removing noise signals. Dr. Yuba discussed the screening and validation of hourly LCS data, while Dr. Minoura covered topics related to data interpretation, visualization, and trend analysis.

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Challenges and Ways Forward

In the last session, Dr. Alison Simcox from the U.S. Environmental Protection Agency (US-EPA) was invited to share insights on LCS experiences. She clarified that LCS data was not deemed an official guideline, and further studies on its functionality were being considered. Two key questions were introduced: the challenges encountered by LCS and Hybrid Air Quality Monitoring Networks (HAQMN) in Asian countries and potential collaborations for promoting LCS in these regions. Commenting on the wrap-up for the way forward, challenges related to technology and policy in utilizing LCS were emphasized, with a focus on the need for capacity building to address issues such as calibration and data interpretation. Dr. Alison stressed the importance of understanding the purpose of LCS usage, whether it was identifying wildfires, creating smoke maps, or monitoring global changes in PM2.5.

Mr. Kenichiro Fukunaga, Deputy Director General of ACAP, delivered the Closing Remarks and conveyed his gratitude to various organizations and participants for their contributions to the workshop and to the EANET Low-cost sensor project. He expressed expectations for the expansion and enhancement of LCS activities in monitoring, research, and capacity building.

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Useful Resources:

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  • View the workshop’s photos on Flickr.

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Find out more about EANET’s Project Fund and Project Activities.

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Photo credits: cover photo of Vietnam (2021) by Hoach Le Dinh; all other photos: all rights reserved to EANET.