Reliable, continuous data is the foundation of air quality governance. Critically evaluate the gaps in India's ambient air quality monitoring network and suggest reforms.

Air quality governance runs on monitoring data. GRAP triggers, NCAP fund releases and health advisories all depend on it. The Central Pollution Control Board (CPCB) runs a network of 634 Continuous Ambient Air Quality Monitoring Stations (CAAQMS). It reaches widely, but Deepavali 2026 showed gaps that open exactly when pollution peaks [1].

Strengths of the network

• Real-time national coverage: station-level data showed about 70% of CAAQMS logged 'severe' PM2.5 peaks (≥250 µg/m³). These peaks occurred in at least seven States besides Delhi, which shows the problem is not Delhi-centric [1].
• Quality control: analysers are calibrated up to 1,000 µg/m³. Rejecting unreliable out-of-range values is sound practice [1].
• Policy anchor: NCAP targets up to 40% PM10 reduction by 2025-26, and its city funding is tied to measured performance [2].

Gaps

• Uptime: only 571 of 634 stations were live during Deepavali [1].
• Blackouts at peaks: many stations went silent after logging values close to 1,000 µg/m³, before crossing the calibration limit. CPCB's explanation does not cover these cases [1]. Missing peak hours pull down 24-hour averages, so a "data gap" looks like cleaner air.
• Information loss: deleting an above-range value throws away one certain fact: the air was at least 1,000 µg/m³.
• Metric mismatch: NCAP judges cities on annual PM10 [2]. About 64% of funds went to road dust, so combustion-driven PM2.5 spikes get too little weight [3].
• Weak capacity: Delhi and Noida had used under 40% of NCAP funds by May 2024 [3].

Reforms

• Flag, don't delete: publish out-of-range readings marked "above range" instead of leaving blanks.
• Public downtime log: list outages by station with reasons, to show whether gaps cluster at peak hours.
• PM2.5 and peak-day indicators in NCAP: add these so festival and winter spikes count when funds are released, addressing CSE's concern about the PM10 focus [3].
• Spend on upkeep: SPCBs should use unspent NCAP funds for maintenance, backup power and higher-range analysers.

India has built a monitoring network of real scale, but it is least reliable during a crisis. Flagged data, open downtime records and PM2.5-linked targets would turn readings into accountability. That would advance the right to clean air under Article 21 and SDG target 3.9.