Ground-breaking Research on Particulate Matter in Northern India

Ground-breaking Research on Particulate Matter in Northern India


A researcher from the Indian Institute of Technology (IIT) Jodhpur has published pioneering research in the journal Nature Communications, providing new insights into the sources and composition of particulate matter (PM) in Northern India and its adverse effects on human health.

  • The study emphasizes the critical need to address inefficient local combustion processes, such as biomass and fossil fuel burning, including traffic emissions, to effectively reduce health risks associated with PM exposure in Northern India.

GS-03 (Conservation)

Key Questions for Policymakers:

The research identifies three essential questions that policymakers must consider to develop effective air pollution mitigation policies:

  • Source Identification: Clear identification of fine PM (PM2.5) sources and their absolute contributions, with a distinct separation of local and regional origins.
  • Emission Distinction: Comprehensive differentiation between PM directly emitted and those formed through atmospheric processes.
  • Health Impact Correlation: Assessment of PM harmfulness by correlating its oxidative potential with local and regional sources in the study area.

Research Findings:

The study was conducted at five sites across the Indo-Gangetic Plain, including locations both inside and outside Delhi. Key findings include:

  • Uniform PM Concentration: High PM concentrations were observed throughout the region, though the chemical composition varied significantly due to dominant local emission sources and formation processes.
  • Within Delhi: PM pollution is predominantly caused by ammonium chloride and organic aerosols from traffic exhaust, residential heating, and oxidation products of fossil fuel emissions formed in the atmosphere.
  • Outside Delhi: The primary contributors are ammonium sulphate and ammonium nitrate, along with secondary organic aerosols from biomass burning vapours.
  • Common Contributors: Across all locations, organic aerosols from the incomplete combustion of biomass and fossil fuels, including traffic emissions, were identified as major contributors to PM oxidative potential.


  • This study underscores the importance of targeting local sources of pollution, particularly inefficient combustion processes, to mitigate PM-related health risks in Northern India.
  • By addressing these key areas, policymakers can create more effective strategies to improve air quality and protect public health.

Particle Pollution:

  • Particle pollution are also known as particulate matter (PM).
  • It consists of tiny solid or liquid particles suspended in the air that includes: Dust, Dirt, Soot, Smoke, Liquid droplets, Sources of Particle Pollution.
  • Particle pollution arises from two main types of sources:
    • Primary Sources: These emit particles directly into the air.
    • Secondary Sources: These release gases that can form particles. Power plants and coal fires are typical examples.
  • Some sources can be either primary or secondary, such as factories, vehicles, and construction sites. Emissions from these sources include smoke from fires and pollutants released by power plants, industrial facilities, and vehicles.

Types of Particulate Matter

  • PM10: These are inhalable particles with diameters of 10 micrometers or smaller. They are relatively larger and visible as fine dust or smoke. Sources include dust from construction sites, pollen, and vehicle and industrial emissions.
  • PM2.5: These fine inhalable particles have diameters of 2.5 micrometers or smaller and are not visible to the naked eye. They often result from combustion processes like burning fossil fuels, vehicle emissions, and cooking. Due to their small size, PM2.5 particles can penetrate deep into the lungs and enter the bloodstream, posing significant health risks.

Health Impacts of Particulate Pollution:

  • Respiratory Problems: Inhaling PM can cause or worsen asthma, bronchitis, and other respiratory infections.
  • Cardiovascular Effects: PM pollution is linked to increased risks of heart attacks, strokes, and other cardiovascular diseases. Fine particles can enter the bloodstream and contribute to plaque buildup in the arteries.
  • Reduced Lung Function: Long-term exposure to PM can impair lung function, making breathing more difficult.
  • Allergies and Irritation: Particulate matter can trigger allergies and irritate the eyes, nose, and throat, leading to coughing, sneezing, and watery eyes.
  • Premature Death: High levels of PM pollution are associated with increased mortality rates, especially among individuals with pre-existing health conditions and the elderly.
  • Cancer Risk: Certain types of PM, such as diesel exhaust particles and some heavy metals, are carcinogenic and increase the risk of lung cancer.
  • Developmental Issues: Pregnant women exposed to high PM levels may face complications like preterm birth, low birth weight, and developmental issues in their children.
  • Impaired Lung Growth in Children: Children exposed to PM pollution may experience reduced lung growth and development, leading to long-term respiratory problems.
  • Aggravation of Existing Conditions: Individuals with pre-existing respiratory and cardiovascular conditions are particularly vulnerable, with PM pollution exacerbating their symptoms and increasing the severity of their conditions.