Particulate matter UPSC Notes

Particulate matter is the minute solid particles or liquid droplets in the air such as dust, mist, fumes, smoke and smog. Present in vehicle emissions, smoke particles from fires, dust, and ash from industries.

These Particles can be classified into two categories:

1. Viable: For example, minute living organisms’ bacteria, fungi, moulds, algae etc. Humans are allergic to some fungi found in the air.
2. Non–Viable: Classified according to their nature and size:

• Smoke particles: Consist of solid or mixture of solid & liquid particles formed during combustion of organic matter. For example, Fly ash.
• Dust: fine solids (over 1mm in dia), produced during crushing, grinding & attribution of solid materials. For example, Sand from sandblasting, sawdust from woodwork, pulverized coal, cement & fly ash, and dust storms.
• Mist: By Particles of liquid spray in the air and by condensation of vapour. For example, Sulphuric acid mist, herbicides & insecticides that miss their targets & travel through the air.
• Fumes: Obtained by condensation of vapour during sublimation, distillation, boiling and several other chemical reactions (gas to solid).

Sources of Particulate matter:

On the basis of its source, particulate matter can be of two types:

1. Fugitive Particulate Matter Emissions are Air pollutants originating from spatially distributed sources and a wide array of activities (non-point sources)
2. Specific discharge points such as exhausts and stacks (such as chimneys, pipes, vents, or ducts).

Non-Point Sources:

Non-point sources of particulate matter (PM) refer to diffuse pollution sources that are not concentrated in one location, i.e. such pollution originates from all areas. We have several examples of such pollution:

1. Road Dust and Soil Dust: Dust from unpaved roads, construction sites, and agricultural fields contributes significantly to airborne particulate matter. Wind, vehicle movement, and human activity stir up soil particles, which are then released into the atmosphere.
2. Vehicular Pollution: Emissions from vehicles, including cars, trucks, and buses, release fine particles into the air. Exhaust fumes contain soot and other pollutants, which contribute to respiratory problems and poor air quality, especially in urban areas.
3. Biomass Burning: The burning of fuel wood, crop residues, and biomass (such as stubble burning) releases large amounts of particulate matter. During such a process small particles of ash or dust get violently suspended along with the rising air.

Point sources

Those pollution sources are concentrated at a point. For example:

1. Burning of Municipal solid waste.
2. Pollution from Construction and demolition sites
3. Industry and DG sets.
4. Mining Areas
5. Volcanic eruptions
6. Forest fires

Effects of Particulate pollutants:

The Effect of particulate matter depends on its size.

PM10

PM10 are particles with a diameter of 10 micrometres or less. These are small enough to pass through the throat and nose and enter the lungs. Once inhaled, these particles can affect the heart and lungs and cause serious health effects.

In fact, any particle Greater than 5 microns is likely to lodge in the nasal passage. Anything that is passed through the nasal passage, gets into our lungs and is more dangerous.

Note that PM10 includes PM2.5

PM2.5

PM2.5 are particles with a diameter of 2.5 micrometres or less. These particles are so small they can get deep into the lungs and into the bloodstream. There is sufficient evidence that exposure to PM2.5 over long periods (years) can cause adverse health effects.

PM 2.5 includes pollutants like sulphate, nitrate and black carbon, which pose the greatest health risk.

Sources of PM2.5 “include:

• Internal combustion engines,
• power generation,
• industrial and agricultural processes,
• construction, and
• residential wood and coal burning.
• The most common natural sources of PM2.5 are dust storms, sandstorms, and wildfires.

Health Risks of Particulate matter

As urban air quality declines, the risk of stroke, heart disease, lung cancer, and chronic and acute respiratory diseases, including asthma, increases for the people who live in them.

• Respiratory Diseases: PM causes lung inflammation, worsens asthma, and increases chronic obstructive pulmonary disease (COPD) risk, leading to breathing difficulties.
• Cardiovascular Problems: Fine PM enters the bloodstream, triggering heart attacks, strokes, hypertension, and worsening pre-existing heart conditions, increasing mortality risk.
• Reduced Lung Function: Long-term exposure damages lung tissues, reduces oxygen exchange, and impairs lung growth in children, causing lifelong respiratory issues.
• Cancer Risk: PM contains carcinogens like benzene and heavy metals, increasing the risk of lung cancer and other respiratory malignancies over time.
• Immune System Weakening: Chronic PM exposure disrupts immune responses, making individuals more susceptible to infections, allergies, and autoimmune disorders like rheumatoid arthritis.

Delhi Smog

Each year in the months of November and December the air quality in the Northern Plains of India deteriorates severely. This is often attributed to the burning of Agricultural biomass and the burning of crackers during the festival of Diwali. This leads to the formation of Classical Smog in Delhi each year. We have discussed the Classical and Photochemical smog in a previous chapter already.

In Delhi, vehicular emissions, biomass burning, industrial pollution, and stagnant cold air trapping pollutants make it more severe. High particulate matter (PM2.5, PM10) causes severe health issues, reduced visibility, and respiratory diseases.

An IIT Kanpur report (2016) on this problem has summarised the problem as follows and presented the following solutions:

Sources of Winter Smog	Solutions
1.       Municipal Solid Waste (MSW) Burning: Open waste burning in Delhi’s large landfills releases toxic fumes and particulate matter.	Stop MSW burning by improving collection and disposal (landfill and waste-to-energy plants).
2.       Secondary Particles (Power Plants): Sulphur and nitrogen oxides contribute to smog formation.	De-SOx-ing and De-NOx-ing at Power Plants within 300 km of Delhi.
3.       Agriculural Biomass Burning: Stubble burning releases thick smoke and greenhouse gases.	Prevent crop residue burning, promote energy production, biogas generation, composting, and biochar.
4.       Secondary Organic Aerosols: Petrol vapors and industrial solvents react to form smog.	Install vapour recovery systems at petrol pumps to control evaporative emissions.
5.       Hotels/Restaurants: Burning coal releases pollutants worsening air quality.	Stop the use of coal in cities.
6.       Road Dust and Soil Dust: Resuspended dust from roads worsens air quality.	Vacuum sweeping of major roads, Carpeting of shoulders, Mechanical sweeping with water wash, Planting shrubs and grass covers.
7.       Vehicles: Emissions from fuel combustion and exhaust cause air pollution.	Implementation of BS-VI fuel standards. Promote electric/hybrid vehicles, retrofit diesel particulate filters, and regular vehicle inspections.
8.       Domestic Cooking: The use of biomass fuels emits harmful smoke and particulates.	Provide LPG to all households.
9.       Construction and Demolition: Dust and debris from construction sites pollute the air.	Cover construction areas with fine screens, cover raw materials, and use water spray and windbreakers.
10.   Concrete Batching: Cement dust and fine particles increase air pollution.	Install bag filters at silos, use enclosures, hoods, curtains, and conveyor belts.
11.   Industry and Diesel Generator (DG) Sets: Factories and diesel generators emit sulphur dioxide and particulates.	Reduce sulphur content in industrial fuel, minimize DG set usage, and ensure uninterrupted power supply.
12.   Fly Ash: Residue from coal plants disperses fine particulate pollutants.	Use windbreakers, water spraying, and reclamation methods.

Graded Response Action Plan (GRAP)

It was notified in January 2017 based on SC order, for prevention, control and abatement of air pollution in Delhi and NCR.

• The Environmental Pollution (Prevention and Control) Authority (EPCA) enforces GRAP, which was formed under the Environment Protection Act, 1986.
• It identifies graded measures and implementing agencies for response to four AQI categories, namely, Moderate to Poor, Very Poor, Severe and Severe + or Emergency.

Actions taken at different stages of GRAP

• Stage I – ‘Poor’ Air Quality (AQI ranging between 201-300): Enforce NGT / Hon’ble SC’s order on over-aged diesel/petrol vehicles.
• Stage II – ‘Very Poor’ (AQI 301-400): Rigorous actions to combat air pollution at identified hotspots in the region.
• Stage III – ‘Severe’ (AQI 401-450): Impose strict restrictions on BS III petrol and BS IV diesel four-wheelers in certain areas and may suspend physical classes in schools for primary grade children up to Class 5.
• Stage IV – ‘Severe Plus’ (AQI greater than 450): When the AQI exceeds 450, four-wheelers registered outside Delhi, except for electric vehicles, CNG vehicles, and BS-VI diesel vehicles, will not be allowed to enter the city.

When the air quality worsened further, often schemes like Odd-Even were imposed by the state government, in which the odd vehicle number was to ply only on odd dates and vice versa.

Solutions to Particulate Matter:

Solving Road Dust:

1. Stringent implementation of C&D Rules, 2016, and Dust Mitigation notification, 2018.
2. Wall-to-wall paving of roads is to be mandated.
3. Stringent control of dust from construction activities using enclosures, fogging machines, and barriers.
4. Greening and landscaping of all the major arterial roads and national highways after identification of major polluting stretches.
5. Maintenance and repair of roads on priority.
6. Sewage treatment plant-treated water sprinkling system along the roads and at intersecting road junctions and spraying of water twice a day before peak traffic hours.

Technological Solutions for Air

• Air purifiers: High-efficiency particulate Arrestance (HEPA) filters are capable of trapping particles as small as 0.3 microns when judged by the USA’s government standards. The higher the CADR or ‘Clean Air Delivery Rate’ number, the more effective the air purifier is for a given size of room.
• WAYU (Wind Augmentation Purifying Unit): developed by CSIR – NEERI (National Environmental Engineering Research Institute) as a part of the Technology Development Project being funded by DST.
  • Two principals involved:
    • Wind generation for dilution of air pollutants &
    • Active Pollutants Removal: It has filters for Particulate Matter removal and activated carbon (charcoal) and UV lamps for poisonous gas removal such as VOCs and Carbon Monoxide.
  • It has the capacity to purify the air in an area of 500 meters square.

Better Fuel

• Biochar: Charcoal is used as a soil amendment. Made from biomass via pyrolysis.
• Use of BS-VI fuel- Delhi became the first city run on BS-VI fuels. We will read about BS-6 fuels in the later chapters in detail.
• Electric buses and metro are an easy solution as they can effectively use technologies like regenerative braking, to reduce energy usage. They do not emit greenhouse gases and are lighter in weight.
• Delhi is scheduled to run hydrogen-CNG (H-CNG) fuelled buses to curb emissions. H-CNG is a blend of hydrogen and CNG, the ideal hydrogen concentration being 18%. Compared to conventional CNG, the use of H-CNG can reduce the emission of carbon monoxide by up to 70%, besides enabling up to 5% savings in fuel.

Green Crackers:

Green Crakers are developed by CSIR led by the Nagpur-based National Environmental Engineering Research Institute (NEERI) developed green firecrackers. These are named as:

1. Safe Water Releaser (SWAS): has the unique property of releasing water vapour, thereby acting as a suppressant and diluent for gaseous emissions.
2. Safe Thermite Cracker (STAR) &
3. Safe Minimal Aluminium (SAFAL) with a 30% reduction in particulate matter on average using Potassium Nitrate (KNO3) as oxidant. Some of the ‘green crackers’ have also replaced barium nitrate as an oxidiser for combustion. Barium nitrate hurts health when inhaled, irritating the nose, throat and lungs.

They also do not contain other banned chemicals such as lithium, arsenic and lead.

A green logo & Quick Response (QR) coding system has been developed for the differentiation of green crackers from conventional crackers.

Any kind of firecrackers are regulated by the Petroleum and Explosives Safety Organisation (PESO). It’s an autonomous status under DPIIT under M/o Commerce and Industry.

Commission for Air Quality Management (CAQM)

Under the provisions of the recently passed Commission for Air Quality Management in NCR and Adjoining Areas Act, 2021 the government has formed the Commission for Air Quality Management (CAQM).

1. This Law dissolves the 22-year-old Environmental Pollution (Prevention and Control) Authority that has so far addressed air pollution in Delhi. In its place, the Centre has constituted a “permanent” body.
2. Aim: Better coordination, research, identification, and resolution of problems related to air quality in the NCR (National Capital Region) and adjoining areas.
3. Meaning of Adjoining Areas: It include areas in the states of Haryana, Punjab, Rajasthan, and UP where any source of pollution may harm air quality in the NCR.

Functions of CAQM

1. Co-ordinating actions taken under the Ordinance by concerned state governments (Delhi, Haryana, Punjab, Rajasthan, and Uttar Pradesh),
2. Planning and executing plans to prevent and control air pollution in the region,
3. Providing a framework for the identification of air pollutants,
4. Conducting research and development through networking with technical institutions,
5. Training and creating a special workforce to deal with issues related to air pollution, and
6. Preparing various action plans such as increasing plantation and addressing stubble burning.

Powers of the Commission:

1. Restricting activities influencing air quality,
2. Investigating & conducting research related to environmental pollution impacting air quality, Powers exercised through sub-committees (probably – details not clear).
3. Preparing codes and guidelines to prevent and control air pollution, and
4. Issuing directions that will be binding on the concerned person or authority.
5. Main Power: It will be the sole authority with jurisdiction over matters defined in the Act (such as air quality management).  In case of any conflict, its orders or directions will prevail over the orders of the state governments, the CPCB, state PCBs, and state-level statutory bodies.

Penalties:

Any non-compliance or violation of the provisions of the Ordinance or orders and directions of the Commission is punishable with imprisonment of up to five years or a fine of up to one crore rupees or both.  All appeals against the Commission’s orders will be heard by the National Green Tribunal.

Composition of CAQM:

The committee would have 6 permanent members:

• Chairperson: with a tenure of 3 years or till the age of 70 years, whichever is earlier. He would be selected by a committee headed by M/o EFCC as the Chairperson, and having representation from the Ministry of Commerce, Ministry of Road Transport and the Ministry of Science and Tech.
• Two Joint Secretaries from the central government,
• Three persons with knowledge & expertise related to air pollution as independent technical members,

Apart from 6 permanent members, few other members too:

1. Three members from NGOs.
2. The Commission will also include ex-officio members: From the central government and concerned state governments, and technical members from CPCB, ISRO, and NITI
3. Additionally, the Commission may appoint representatives of certain ministries as associate members.

Sub-Committees:

The Commission is required to form at least three sub-committees, such as: Sub-committee on monitoring and identification, a Sub-committee on safeguarding and enforcement, and a Sub-committee on research and development.

These sub-committees are headed by A member of the Commission and will have technical members.

Advantages of CAQM over Environment Protection Authority

The earlier mechanism had several limitations which the CAQM seeks to overcome:

1. Eliminating conflict between states with central direction: Air pollution is a national problem. A state government cannot direct another state government, but this commission can.
2. Permanent Body: This was necessary to allow continuous study, monitoring, vigil and direction as air pollution is a dynamic problem
3. Comprehensive provisions: The commission has power over both rural and urban areas as well as all the states of North India.
4. Monitoring has been a challenge: The government has created many organizations and indices such as:
   1. AQI (Air Quality Index) by the Ministry of Environment,
   2. Comprehensive Environmental Pollution Index (CEPI) by the CPCB,
   3. SAFAR Index by M/o Earth Sciences, and
   4. IndAIR or Indian Air Quality Interactive Repository by CSIR.

The new mechanism would form a uniform standard for all areas based on these data.

5. Greater powers: It has greater powers than the now-abolished Environmental Pollution (Prevention and Control) Authority.
6. Relieving States from Conflict of Interest: States are unable to act against the industries and farmers in their areas due to political reasons. An Independent body would however be free to do so.

The Commission will be the sole authority with jurisdiction over matters defined in the Law (such as air quality management).  In case of any conflict, the orders or directions of the Commission will prevail over the orders of the respective state governments, the Central Pollution Control Board (CPCB), state PCBs, and state-level statutory bodies.

Challenges:

However, there are certain apprehensions about the working of CAQM.

1. Too much penalty: Farmers groups have opposed the bill as they feel that sometimes burning the stubble is the only survival choice that they have, in which scenario up to 1 Crore fine or 5 years of jail is too much.
2. Not all stakeholders are taken into confidence: It has been drafted with little discussion with multiple stakeholders such as industry, small businesses, and farmers. Also, it has been passed in the Parliament without discussion.
3. Enforcement on the ground can be a challenge: A major weakness, environmentalists and experts have said in tackling air pollution in Delhi-NCR, has been the inability of agencies such as the CPCB to consistently enforce rules on the ground.
4. Effectiveness is doubtful: The Environmental Pollution (Prevention and Control) Authority (EPCA) had almost similar powers but failed miserably in cleaning the air even after being in force for more than 20 years.
5. Not effective against latent factors: such as vehicles, roadside dust, and continuous burning of solid waste in landfill sites. These require initiatives from the government.