Elemental Composition and Sources of Fine Particulate Matter (PM_2.5) in Delhi, India

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Air Quality Monitoring

Background:

• Fine particulate matter (PM2.5) poses significant health risks.
• Understanding elemental composition is crucial for identifying pollution sources.
• Delhi experiences severe air pollution, necessitating detailed source apportionment studies.

Purpose of the Study:

• To analyze the elemental composition of PM2.5 in Delhi.
• To investigate seasonal changes in elemental concentrations.
• To identify the primary sources of PM2.5 pollution in Delhi.

Main Methods:

• Elemental analysis of PM2.5 using Wavelength Dispersive X-ray Fluorescence Spectrometer.
• Data collection over a five-year period (January 2017 - December 2021).
• Statistical analysis, including Principal Component Analysis (PCA), for source identification.

Main Results:

• Nineteen elements were identified in PM2.5, with Sulfur (S), Chlorine (Cl), Potassium (K), Calcium (Ca), and Iron (Fe) showing higher concentrations in the post-monsoon season.
• The measured elements constituted approximately 10% of the total PM2.5 mass.
• PCA identified five main sources: crustal/soil/road dust, combustion (biomass burning + fossil fuel combustion), vehicular emissions, industrial emissions, and a mixed source.

Conclusions:

• Elemental composition of PM2.5 in Delhi exhibits distinct seasonal patterns.
• Multiple emission sources contribute to PM2.5 pollution in Delhi.
• Effective air quality management strategies require addressing identified sources like dust, combustion, and vehicular emissions.