Renowned for its pristine air, Shimla, the ‘Queen of Hills,’ is witnessing a significant decline in air quality. Reports from the Himachal Pradesh Pollution Control Board (HPPCB) and the Central Pollution Control Board (CPCB) indicate a steady rise in the city’s Air Quality Index (AQI) over the years. While the average AQI was 35 in 2011-2012, it climbed to 52 by 2024. The increase in pollutants can be attributed to rapid urbanization, the growing number of vehicles, and forest fires.

In 2011-2012, the levels of sulfur dioxide and nitrogen dioxide in Shimla’s air were 2 µg/m³ and 8.1 µg/m³, respectively. The level of respirable suspended particulate matter (PM) was recorded at 40 µg/m³. However, in 2024, the figures show a concerning rise, with sulfur dioxide at 2.1 µg/m³ and nitrogen dioxide at 10.4 µg/m³. The average AQI for 2024 stood at 52, while PM10 levels increased to 51 µg/m³, and PM2.5 reached 18 µg/m³.

Despite Shimla’s air still being classified as ‘good,’ the continuous decline in quality is worrisome. Rising pollution levels pose a growing risk of respiratory diseases such as asthma and bronchitis, especially among children and the elderly.

Interestingly, the average AQI saw slight improvement in 2022-2023, dropping to 47 from 53 recorded in 2020-2021 and 2021-2022. However, discrepancies between HPPCB data and private monitoring agencies remain significant. For instance, on January 15, 2024, HPPCB recorded an AQI of 77, while a private agency reported it as 155.

The absence of annual reports from HPPCB since 2022-2023 has further fueled concerns about the transparency and monitoring of Shimla’s air quality.