Particulate Matter 1 (PM1)
Context:
Recent reports highlight a critical gap in India's air quality monitoring, revealing that PM1 levels in Delhi are likely 20% higher than currently estimated.
Despite posing significantly higher health risks than PM2.5, PM1 remains largely unmonitored and unregulated in India
About PM1:
PM1 refers to “particulate matter with an aerodynamic diameter of less than 1 micrometer.”
These are classified as ultra-fine particles making them significantly smaller and more potent than the commonly tracked PM2.5 and PM10.
PM1 is not included in regulatory frameworks by the Central Pollution Control Board (CPCB) or at the state level.
Characteristics:
Due to their negligible mass but high surface area, they remain suspended in the atmosphere for longer periods and can travel greater distances
This facilitates the transport of toxic chemicals.
Sources:
PM1 primarily originates from high-temperature combustion processes (anthropogenic sources) such as:
combustion of fossil fuels,
vehicular exhaust
industrial emissions.
Recondensed organic vapors and metals
They also play a major role in New Particle Formation (NPF) events, where gaseous pollutants convert into particulate matter under specific atmospheric conditions.
Health Risks:
Deep Penetration:
Unlike larger particles, PM1 can bypass the body's natural defences, penetrating deep into the alveolar regions of the lungs and crossing into the bloodstream.
Chemical Composition:
PM1 particles often carry hazardous chemicals and heavy metals such as lead, cadmium, chromium, and nickel, which are strongly linked to heart disease, cancer, and other health conditions
Systemic Impact:
Once in the blood, they can translocate to vital organs, including the brain and heart.
Studies have linked PM1 exposure to cardiovascular diseases, hypertension in children, neurological disorders, and adverse birth outcomes like Preterm Birth (PTB) and Low Birth Weight (LBW).
Status in India:
Currently, PM1 is not listed as a criteria pollutant under the National Ambient Air Quality Standards (NAAQS).
This means there are no safety standards or dedicated monitoring stations for it.