Despite a 28-point improvement in Gurugram’s air quality index (AQI), which stood at 350 on Wednesday, the concentration of PM2.5, or fine particulate matter, remained alarmingly high at an average of 222 µg/m³ till 5pm, measuring 5.5 times above the national safe limit and 14.8 times higher than the World Health Organization (WHO) standard of 15 µg/m³, according to data from the Central Pollution Control Board (CPCB).
Between November 1 and 12, average PM2.5 levels rose from 136 µg/m³ to 222.18 µg/m³, as per CPCB hourly data analysed by Envirocatalysts, indicating that despite marginal AQI changes, toxic pollutants in the air continued to accumulate.
Considered about one-thirtieth the width of a human hair, PM2.5 consists of dust, black carbon, heavy metals, sulphates, nitrates and smoke, particles capable of penetrating deep into the lungs and bloodstream. Prolonged exposure, experts warn, can trigger heart diseases, strokes, respiratory illnesses, and lung cancer.
According to CPCB’s official scale, PM2.5 concentrations in November have fluctuated between 2.5 and 5.45 times higher than the National Ambient Air Quality Standards (NAAQS) limit of 60 µg/m³. “On November 5, the lowest increase in PM2.5 levels was seen when its concentrations remained 2.57 times more than the safe limit at 103 µg/m³. Since then, its presence continues to remain amplified,” said Dr Arun Kumar, analyst at Envirocatalysts, a private environmental research firm.
The CPCB-maintained data from three key monitoring stations, NISE Gwal Pahari, Teri Gram and Vikas Sadan, shows that mean PM2.5 concentrations declined slightly from 137 µg/m³ on November 2 to 110 µg/m³ on November 8, before surging continuously over the next five days. Levels rose from 116 µg/m³ on Saturday evening to 164 on Monday, 200 on Tuesday, and 222.18 on Wednesday, the highest this month.
The firm’s analysis showed that while Gurugram recorded the sharpest rise in PM2.5 concentrations, nearby cities also remained in the danger zone, including Faridabad (2.1 to 3.2 times the safe limit), Ballabhgarh (1.6 to 3.6 times), and Bhiwani (2.1 to 3.2 times). In contrast, Panipat (2.6 to 8.6 times), Rohtak (3.25 to 6.76 times), and Bahadurgarh (0.37 to 8.21 times) fared worse. “While the pollution control board’s efforts largely remain focused on NCR-centric emissions, there’s an urgent need for stronger policy measures to track and manage transboundary pollution,” said Kumar. “Implementing an airshed-based approach, which recognises that air does not adhere to administrative boundaries, can enable coordinated action across districts.”
Environmental activist Bhavreen Kandhari, a member of My Right To Breathe, said policymakers must prioritise tracking PM2.5 rather than relying only on AQI scores. “While AQI scores give a broad-brush snapshot of air quality, PM2.5 concentrations reveal the real threat to human health. They are directly measurable, consistent across systems, and carry toxic metals and chemicals deep into our lungs and bloodstream,” she said.
Gurugram’s minimum temperature on Wednesday stood at 11.5°C, meanwhile, the maximum was at 27.6°C, according to data from the India Meteorological Department (IMD).