Air quality changes in Delhi due to open waste burning: an accidental fire in Bhalswa landfill

Open waste burning is a significant contributor to air pollution in urban cities. The contribution includes sources from local and centralized waste burning. This paper focuses on the air quality changes in the surrounding regions of the Bhalswa landfill in the north-west part of Delhi, India, where a fire broke out accidentally in the landfill from 20 April 2022 to 8 May 2022. Bhalswa landfill is one among the three major landfills in Delhi, and during the waste burning, PM2.5 shows a maximum average concentration of about 107.32 and 338 mu g/m(3) for PM10. The average PM2.5 concentration increment was around 45-55%, and for PM10, it was 40-50% during the fire. Apart from particulate matter, fumes generated during open waste burning emit gaseous and toxic substances. Dispersion of pollutants was less during low (< 3 m/s) and calm winds (< 1 m/s) and more during high winds (> 3 m/s). The correlation value (R-2) of gaseous pollutants with PM2.5 was significant and exhibited a moderate correlation (R-2 around 0.5-0.6). It is high time for residents, government authorities and various other stack holders to be aware and implement policies and adopt technologies for segregation and processing. Identifying potential reuse of waste in energy and volume reduction forms should be encouraged to avoid further accidents/incidents related to open waste burning. The study's outcomes indicate the potential changes that occurred in regional air quality during the open waste burning in a short period.