A recent study highlights a significant correlation between rising temperatures and increased PM2.5 pollution levels in major Indian cities, posing a substantial environmental challenge. Titled "Influence of Temperature on PM2.5 Concentration Over Major Cities in India During April and May", the study examined data from Delhi, Lucknow, Kolkata, Mumbai, and Patna, revealing the impact of temperature on air quality. New Delhi- PM2.5 levels dropped by 28.4% from 93.81µg/m³ in April-May 2022 to 67.19 µg/m³' in the same period in 2023, but rose by 21.3% to 81.53µg/m³' in 2024. Concurrently, the average temperature decreased from 32.15°C in 2022 to 28.72°C in 2023, and then increased by 11% to 31.87°C in 2024.

Kolkata- PM2.5 levels increased by 28% from 26.50 µg/m³' in 2022 to 33.93 µg/m³ in 2023, followed by an 11.3% decrease to 30.10 µg/m³ in 2024. The city's temperature remained stable between 2022 and 2023, with a slight decrease from 30.28°C to 30.27°C, and then rose by 2.5% to 31.04°C in 2024.

Patna- Both PM2.5 levels and average temperature showed fluctuations. PM2.5 levels decreased from 2022 to 2023, followed by a significant rise in 2024. Similarly, temperature trends showed a decrease from 2022 to 2023 and an increase in 2024.

Lucknow-PM2.5 levels decreased by 27.7% from 73.16 µg/m³ in 2022 to 52.87 µg/m³ in 2023, then increased by 17.6% to 62.17 µg/m³ in 2024. Temperature trends mirrored this pattern, suggesting a strong influence of temperature changes on air quality.

Mumbai- The temperature slightly decreased from 29.55°C in 2022 to 29.42°C in 2023, and further to 29.20?C in 2024. PM2.5 levels were 43.17 µg/m³ in 2022, which decreased to 30.84 µg/m³ in 2023, and slightly further to 30.46 µg/m³ in 2024.

The study utilised data from the Central Pollution Control Board (CPCB) for PM2.5 concentrations and temperature data from the ERA5 dataset, covering April and May for the years 2022, 2023, and 2024. The analysis indicated that meteorological parameters significantly influence PM2.5 concentrations. Dr Palak Balyan, Research Lead, Climate Trends, stated, "PM2.5 concentration can be influenced by various factors, including temperature. Extreme temperatures can enhance photochemical reactions, leading to the formation of secondary pollutants, while also affecting atmospheric stability and pollutant dispersion. Understanding the interplay between PM2.5 levels and temperature is crucial for developing effective air quality management and public health protection strategies." Dr Harshal Salve, Additional Professor-Community Medicine, AIIMS New Delhi, commented, "High levels of pollutants such as PM2.5 and PM10 can exacerbate respiratory conditions, trigger asthma attacks, and lead to cardiovascular problems. We already see vulnerable groups, including children and the elderly, exhibiting heightened signs of these during the winter months; its burden during summer further adds to the risk. Policymakers must undertake measures that reduce sources of air pollution throughout the year and not just mask them during the winter months. Climate and health co-benefits of air pollution mitigation must be considered while ideating and implementing policies."

(Source: ET)