Union Minister Dr Jitendra Singh inaugurated the Integrated Atmospheric Chemistry and Aerosol Toxicity Analysis Laboratory (AATAL) on 24 October 2026 at the Delhi branch of the Indian Institute of Tropical Meteorology (IITM) in New Rajendra Nagar. Described as the world’s first integrated air pollution analysis facility for Delhi NCR, AATAL moves Delhi air quality index reporting beyond a single number to chemical composition, real time sources and health risk. The laboratory is linked to the AIRWISE forecasting system that gives a Delhi pollution forecast at 400 metre resolution for the next 72 hours.
Delhi Air Quality Index: Why AATAL Goes Beyond AQI Numbers
The Delhi air quality index is a single number from 0 to 500 that reports how clean or polluted the air is at a given time. The Air Quality Index (AQI) converts measured levels of eight pollutants, including PM2.5, PM10, nitrogen dioxide, sulphur dioxide, carbon monoxide, ozone, ammonia and lead, into one colour coded score. The worst performing pollutant decides the final score for that location and hour.
Air quality in Delhi is measured through a network of Continuous Ambient Air Quality Monitoring Stations (CAAQMS) run by the Central Pollution Control Board (CPCB), the Delhi Pollution Control Committee (DPCC) and the SAFAR network of IITM. Each station records pollutant levels every hour. The system uses running averages, 24 hour averages for particles and gases and 8 hour averages for carbon monoxide and ozone, to calculate sub indices. A minimum of 16 hours of data and at least three pollutants, including PM2.5 or PM10, are needed for a valid AQI.
AATAL changes this reporting line. Earlier public discussion centred on whether the Delhi AQI was 100 or 200. During the inauguration demo, the screen showed an overall level of around 180 while transport contributed about 25 percent at that moment. That shift matters. AQI tells how much pollution is present. AATAL adds what the pollution is made of, where it comes from and what harm each part may cause. This compositional view lets authorities target the actual source instead of applying the same blanket curb across Delhi NCR.
| AQI Category | AQI Range | What It Signals |
|---|---|---|
| Good | 0 to 50 | Air is clean with minimal health risk |
| Satisfactory | 51 to 100 | Air is acceptable for most people |
| Moderate | 101 to 200 | Sensitive groups may feel discomfort |
| Poor | 201 to 300 | Most people feel effects on long exposure |
| Very Poor | 301 to 400 | Health risk rises even on short exposure |
| Severe | 401 to 500 | Emergency conditions that affect even healthy people |
What Is Aerosol and Atmospheric Chemistry?
An aerosol is a suspension of tiny solid particles or liquid droplets in the air. In Delhi’s context, aerosols include dust, smoke, soot, sulphates, nitrates, metals and droplets formed when gases react in sunlight. PM2.5, particles smaller than 2.5 micrometres, is the most tracked aerosol because it can enter deep into the lungs and blood.
Atmospheric chemistry is the study of how gases and aerosols behave, mix and change in the air. Pollutants do not stay as emitted. Sulphur dioxide, nitrogen oxides, ammonia and volatile organic compounds react in the atmosphere to form new particles called secondary aerosols. These secondary particles now form a large share of Delhi’s PM2.5. Early AATAL data shows roughly 40 percent of Delhi’s PM2.5 is primary particles released directly, while about 60 percent is secondary material formed through such reactions.
Aerosol toxicity analysis studies which parts of this mix are most harmful. Two days can show the same AQI yet carry very different risks if one day has more metals, toxic organics or carcinogenic traces. AATAL is built to separate that detail. It can flag metallic elements, microplastics traces and other potentially carcinogenic components and pass that evidence to health authorities for closer risk review.
How AATAL Identifies Sources and Toxicity in Real Time
AATAL sits at the IITM Delhi branch in New Rajendra Nagar and unites measurement, chemical analysis, source tracking and decision support in one lab. The setup restores live source detail for Delhi after a gap of nearly three years. The earlier IIT Kanpur based apportionment display stopped in November 2023.
The core method is real time source apportionment. This means matching the chemical fingerprint found in the air at a given hour to known source profiles. AATAL can separate vehicular emissions, industrial activity, biomass and crop residue burning, construction and road dust, waste burning and pollutants carried in from nearby regions. For each hour it estimates the share of each source in current PM2.5.
Inaugural data showed the value of this split. On 24 October 2026, vehicles formed about 25 percent of Delhi’s PM2.5, followed by secondary organic aerosols at 18.4 percent, secondary inorganic aerosols at 16.5 percent, road dust at 10.9 percent and waste burning at 5 percent. A day earlier, when Delhi air stayed in the poor band, secondary organic aerosols led at 24.6 percent, while vehicles and secondary inorganic aerosols each gave 20.7 percent. Road dust stayed between 5 and 10 percent across those days. The project team noted that primary particles, secondary inorganic aerosols and secondary organic aerosols each account for close to one third of PM2.5, with metals and toxic traces forming the rest.
The lab also studies transformation. Secondary organic aerosols form when volatile organic compounds from vehicles, solvents, industry and vegetation react in sunlight. Secondary inorganic aerosols form when sulphur dioxide, nitrogen oxides and ammonia turn into sulphates and nitrates. Moisture, fog and winter haze in north India speed up these changes. AATAL tracks that interaction, which helps explain why pollution can stay high even when direct emissions dip.
Can Air Quality Be Forecasted? AIRWISE 400 Metre, 72 Hour System
Yes, air quality can be forecasted using weather models, emission maps and live pollution data. AATAL is integrated with AIRWISE, the full name of which is Air Quality Warning and Integrated Decision Support System for Emissions. AIRWISE was developed by IITM and combines observations, chemical transport forecasts and source shares to guide action.
AIRWISE gives block level detail. It produces hourly forecasts for PM2.5, PM10, carbon monoxide and dust for the next 72 hours at an ultra fine grid of 400 metres for Delhi. This grid can show how one pocket, near a traffic corridor or construction cluster, may turn worse while another stays moderate. The team said the same setup also supports outlooks for the next four days to help agencies prepare early.
The engine behind the forecast is a coupled weather chemistry model. It starts from near real time aerosol inputs from ground stations and satellites, including aerosol optical depth and fire signals for stubble burning, plus dust storm inputs and boundary layer height. The model is initialised each evening and the products are released in the morning through the public portal ews.tropmet.res.in. Assimilation of live PM2.5 and satellite data has cut initial error sharply in trials during October 2019 to February 2020. Forecast skill stays strong for unhealthy and very unhealthy bands, though bias grows slightly by day three.
AATAL adds the source layer to this forecast. AIRWISE does not only say which area may breach the poor or very poor band. It also points to which source is likely to drive that breach in that pocket. That lets field teams direct water sprinkling, dust checks or traffic smoothing to the right place at the right hour.
| Feature | Earlier Early Warning Setup | AATAL Plus AIRWISE Setup |
|---|---|---|
| Spatial detail for Delhi | City scale and 10 km regional view | 400 metre neighbourhood view for Delhi |
| Lead time | Up to 72 hours | 72 hours plus 4 day outlook brief |
| What is reported | AQI number and pollutant level | AQI plus chemical mix, source share and toxicity clues |
| Decision use | General alerts under GRAP | Source and location specific action under GRAP |
Why Delhi Pollution Is High and How the Facility Supports GRAP Action
Delhi pollution is high because many sources overlap in a landlocked basin with weak winter dispersion. Vehicles, industry, biomass and crop residue smoke, construction and road dust, waste burning and dust carried from surrounding areas all add to the load. In October to December, cool air, low mixing height, calm winds and fog trap this mix near the ground. Fire emissions from the wider region and local secondary formation then push PM2.5 up fast. This seasonal pattern explains why public concern and emergency curbs peak each November and December.
The Commission for Air Quality Management (CAQM) manages the response through the Graded Response Action Plan (GRAP). GRAP is a step wise emergency plan for the whole National Capital Region (NCR). Action is tied to Delhi AQI bands and to forecasts from the India Meteorological Department (IMD) and IITM. Preventive steps start early if the forecast shows a breach that is likely to persist.
| GRAP Stage | Delhi AQI Band | Type of Action |
|---|---|---|
| Stage 1 Poor | 201 to 300 | Dust control, traffic smoothing, stronger public transport, power supply upkeep to cut generator use |
| Stage 2 Very Poor | 301 to 400 | Daily mechanised sweeping, water sprinkling with suppressants, hotspot focus, staggered office timings in core NCR districts |
| Stage 3 Severe | 401 to 450 | Curbs on construction, mining and polluting industry, work from home options for many offices |
| Stage 4 Severe Plus | Above 450 | Truck entry limits, ban on older diesel trucks, closure of most linear construction, strict vehicle checks |
AATAL feeds this chain with measurement based proof. For CAQM, municipal bodies, state pollution boards and the CPCB, the lab identifies which sector and which hotspot is driving the rise, so GRAP curbs can focus there. After action, the same source data helps check whether the curb worked. Dr Sachin Ghude, Project Director of the Metropolitan Air Quality and Weather Service, said this loop will cover stubble, vehicles, dust and construction and help assess effectiveness rather than rely on city average AQI alone.
IITM Delhi and Mission Mausam: The Institutional Backbone
The Indian Institute of Tropical Meteorology (IITM) is an autonomous institute under the Ministry of Earth Sciences. It was founded as the Institute of Tropical Meteorology on 17 November 1962 in Pune as a unit of the India Meteorological Department, became autonomous on 1 April 1971 and moved under the Ministry of Earth Sciences on 12 July 2006. Its headquarter campus is at Pashan in Pune. It leads national work on monsoon, weather and climate modelling and runs the System of Air Quality Forecasting and Research (SAFAR) and the Delhi early warning network.
AATAL has been set up under Mission Mausam, a central sector umbrella scheme of the Ministry of Earth Sciences to make India weather ready and climate smart. The Union Cabinet approved the mission in 2024 with an outlay of ₹2,000 crore for 2024-25 and 2025-26. The mission was launched on 14 January 2025. For 2026-27, the budget estimate is ₹1,342.29 crore. The 2026 to 2031 phase runs through six verticals, including ATCOMP for atmospheric composition monitoring, modelling and prediction, which covers AATAL type work.
The inauguration was attended by Dr T. Srinivasa Kumar, Secretary in the Ministry of Earth Sciences, Dr A. Suryachandra Rao, Director of IITM, and Dr Mrutyunjay Mohapatra, Director General of IMD. Dr Jitendra Singh stressed a whole of government approach, linking the Ministry of Earth Sciences, the Ministry of Environment, Forest and Climate Change, pollution control boards, CAQM and disaster management bodies. The test ahead is translation. High resolution forecasts and toxicity clues will improve Delhi NCR air only if civic agencies act on street level evidence and coordinate across state borders.
Key Takeaways
- AATAL was inaugurated on 24 October 2026 at the IITM Delhi branch by Union Minister Dr Jitendra Singh as the world’s first integrated air pollution analysis facility for Delhi NCR.
- AATAL full form is Integrated Atmospheric Chemistry and Aerosol Toxicity Analysis Laboratory and it was set up under Mission Mausam.
- AIRWISE linked to AATAL gives forecasts at 400 metre resolution for the next 72 hours for Delhi, with a 4 day outlook brief.
- Demo data showed transport at about 25 percent of Delhi PM2.5 with overall level near 180, while secondary organic and inorganic aerosols each form close to one third of PM2.5 over time.
- IITM, founded on 17 November 1962 in Pune and now under the Ministry of Earth Sciences, leads SAFAR and the Delhi early warning network.
- The facility supports CAQM and GRAP, the four stage emergency plan invoked at AQI bands 201 to 300, 301 to 400, 401 to 450 and above 450.
