Pathways to Improving Air Quality in the Asia-Pacific Region through Technology Cooperation

Pathways to Improving Air Quality in the Asia-Pacific Region through Technology Cooperation is an ESCAP policy brief outlining the current air quality situation, technical and institutional gaps, and priority technologies to advance air pollution management in the Asia-Pacific region. The document supports implementation of the Regional Action Programme on Air Pollution (RAPAP) by identifying scalable, evidence‑based technological pathways for coordinated regional improvement. 

1. Context and the Severity of Air Pollution in Asia-Pacific
Approximately 90% of the population in Asia and the Pacific is exposed to air pollution levels exceeding WHO guidelines. Many countries—including Bangladesh, India, and Pakistan—consistently rank among the world’s most polluted, with PM2.5 levels above 50 µg/m³, while Nepal and Tajikistan exceed 40 µg/m³, placing them among the global top 10 polluted countries. Even the region’s cleaner countries (Japan, Singapore) exceed the WHO annual PM2.5 guideline of 5 µg/m³. 
Mortality rates associated with air pollution exceed 50 deaths per 100,000 people in most member States, with exceptions such as Japan, the Republic of Korea, and Singapore. Rapid economic growth, urbanization, and the transboundary transport of pollution add layers of complexity to national efforts. This situation motivated member States to establish the RAPAP framework in 2022, focusing on science-based cooperation, best-practices exchange, capacity building, and multilateral partnerships. 

2. Air Quality Management Systems: Gaps and Weaknesses
Institutional and Regulatory Gaps
Most ESCAP countries have enacted ambient air quality standards (AAQS), but many remain far less stringent than WHO guidelines. For example, India’s annual PM2.5 standard is 40 µg/m³, even above WHO Interim Target 1 (35 µg/m³). Enforcement often remains weak, with unclear legal duties for compliance, limited monitoring obligations, and insufficient incorporation of transboundary pollution into national strategies. In many governments, air quality compliance remains more of a “recommended practice” than a binding obligation. 
Technical Capacity and Monitoring Limitations
Although monitoring networks have expanded, significant gaps remain:

Many ESCAP countries lack sufficient monitoring coverage, resulting in incomplete pollutant data.
The Philippines has 105 monitoring stations, but only 15 measure all five key pollutants.
Several countries rely on manual monitoring, limiting real-time assessments.
Air pollutant emission inventories are inconsistent, often outdated or incomplete, especially outside Southeast Asia.
A major concern is the absence of a global standard for air pollutant emissions inventories, unlike the IPCC methodology for GHG inventories.

Countries also struggle to quantify emissions from informal, diffuse sources and link them to national GHG inventories despite shared emission pathways from vehicles, industry, and fossil fuel combustion. 

3. What Member States Say They Need: Survey Findings
A regional survey of 14 ESCAP member States uncovered several priority areas:

Highest demand for innovative technologies lies in the transport sector, followed by open burning and residential emissions in South and Southeast Asia.
Strong interest in satellite and drone-based monitoring, AI-driven modelling, and prediction technologies.
For international cooperation, countries prioritize emission-reduction devices, renewable energy equipment, and air-quality monitoring technologies.
Countries want both short-term, tangible reductions (e.g., filters, cleaner fuels) and long-term system improvements (e.g., monitoring and modelling tools). 
4. Applicability Assessment of 17 Candidate Technologies
ESCAP and partners evaluated 17 technologies across:

feasibility,
implementation gaps,
potential PM reduction,
economic viability,
stakeholder interest.

Technologies span monitoring, modelling, transport, industry/energy, and residential sectors.
Notable examples include:

Low-cost sensors (LCS) – High feasibility, low implementation gaps, suitable for localized monitoring but require calibration under high humidity.
Satellite detection of agricultural burning – High PM-reduction potential; essential for early warning of fires and transboundary haze.
WRF-Chem modelling – Powerful but requires significant technical capacity.
Continuous Emission Monitoring Systems (CEMS) – High PM reduction potential but medium barriers.
Diesel particulate filters (DPFs) – Up to 99% PM reduction, but costly (US$5,000–20,000 per vehicle).
Low-emission zones (LEZs) – Proven to reduce PM2.5 by 10–15% in Seoul and Bangkok pilots.
Improved zig-zag kilns – High PM reduction for brick manufacturing.
Waste-to-energy plants – High PM reduction but varying feasibility.
Cleaner cooking technologies – Strong health and gender co-benefits; success depends on ventilation and household design. 
5. Three Selected Priority Technologies for RAPAP Pilots
During the May 2025 Bangkok consultation workshop, member States voted to prioritize:
1. Diesel Particulate Filters (DPFs)

Reduce PM and black carbon by >90%.
Effective for older diesel fleets.
Financial challenges require cooperation, climate funds, and maintenance capacity.

2. Low-cost sensors with IoT integration

Provide cost-effective real-time monitoring.
Need standardized calibration protocols and capacity-building.

3. Satellite-based monitoring systems

Crucial for detecting fires, agricultural burning, and transboundary haze.
Performance varies across atmospheric and geographical conditions. 
6. Strategic Directions for Implementation
A. Strengthening Legal and Institutional Frameworks
Countries need:

stricter AAQS aligned with WHO AQG;
systematic incorporation of transboundary pollution;
stronger enforcement and clear institutional mandates;
cross-ministry coordination (environment, transport, industry, health, planning). 

B. Improving Technical Capacity and Data Systems

Develop regional calibration protocols for low-cost sensors.
Improve satellite data interpretation and integration with ground networks.
Strengthen emission inventories and link them with GHG inventories.
Expand data-sharing frameworks across ESCAP members. 

C. Scaling Up Pilot Projects
Past pilots were short-lived and small-scale. For durability:

link pilots to national and regional policy;
secure multi‑year financing;
integrate complementary measures (e.g., clean cooking, LEZs, EV transition);
build evaluation and monitoring systems;
use the RAPAP Partnership and Coordination Platform for peer learning. 

🔥 Highlighted Keywords
PM2.5, air quality management, ESCAP, RAPAP, low-cost sensors, satellite monitoring, diesel particulate filters (DPFs), emission inventories, transboundary pollution, WHO guidelines, monitoring systems, WRF-Chem modelling, low-emission zones (LEZs), clean cooking technologies, technical capacity, regional cooperation, Asia-Pacific, pilot technologies, IoT integration, early warning systems.