18 Apr

Recent Air Pollution Issues

< General Studies Home Page

Content

• Delhi’s Air Pollution Problem
• Stubble Burning – Class Discussion
• Fire Crackers
• Green Crackers
• Smelting Industry and Pollution
• Odour Pollution
• Various Air Quality Measuring Initiatives in India

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1) DELHI’S AIR POLLUTION PROBLEM

• Introduction
  • Delhi’s air quality dips drastically every year with the arrival of harvest season during October- November. Though, government generally blames the stubble burning in the neighboring states as the key cause, but the air pollution in Delhi is a complex phenomenon that is dependent on a variety of factors.
• Key Factors include:
  1. Input Pollutants
     • Dust is the biggest cause of pollution during Dry cold weather leads to dust being easily available in the entire region.
     • Vehicular Pollution is the second biggest cause of pollution in
       • According to a study by IIT Kanpur, around 20% of 5 in winters comes from vehicular pollution.
     • Stubble burning
       • At the time of Rabi harvesting around 25% of PM content in Delhi is due to stubble burning.
     • Industries, thermal power plants, burning of waste during winters
     • Diwali Pollution
  2. Meteorological Factors
     • Wind Direction: With the departure of Monsoon, the wind direction in Delhi changes from easterlies to westerlies.
     • Dip In Temperature brings the inversion height to lower levels. The concentration of pollutants in the air increases when his happens.
       • Note: Inversion Height is the layer beyond which pollutants cannot disperse into the upper layer of the
  3. Low Wind speed in winters: High wind speeds are effective in dispersing pollutants, but with arrival of winters, the average wind speed decreases.
• Other factors
  • When compared to other metropolitan (i.e. Kolkata, Mumbai and Chennai) – Delhi is surrounded by high density region on all the sides. The other three cities are located near the coast, thus leaving the breathing space for the cities.
• Steps taken in Delhi in the past to fight Air Pollution:
  • In 1996, the Supreme Court took a note of the extremely poor air quality of Delhi and ordered the closure and relocation of over 1,300 highly polluting industries from Delhi’s residential areas beyond the NCR in a phased manner. Multiple brick kilns were also directed to be relocated outside the city limit.
  • In 1998, the Supreme Court ordered the MoEF&CC to establish an authority for Delhi, which led to the creation of Environment Pollution Control Authority (EPCA) in 1998.
  • Supreme Court subsequently ordered conversion of the whole fleet of DTC buses, taxis and autos to CNG.
  • During this time centre also took several steps:
    • It revamped its Air Quality Monitoring Program and established a network of monitoring stations, under the National Air Quality Program.
  • In 2009, National Ambient Air Quality Standards were revised to include the 12 categories of pollutants including PM 2.5 – a noxious pollutant which can penetrate deep into the lungs and even enter the blood stream.
• Steps taken in recent years to deal with pollution in Delhi
  • The Commission for Air Quality Management in National Capital Region and Adjoining Areas
    • Formed in Oct 2020 through an ordinance to strengthen the air pollution control system in NCR and adjoining region
    • Replaces the EPCA
  • Ban on Coal and other unapproved fuels from 1st Jan 2023
  • Introduction of BS-VI norms for Vehicles
  • Graded Response Action Plan (GRAP)
  • Push for Electric Vehicles – Delhi’s Electric Vehicle Policy, 2019 subsidizes buying of electric vehicle and encourage people to move to electrical
  • Various steps for controlling stubble burning
  • Prohibition on polluting crackers and promotion of green crackers
  • Odd-Even rule for vehicles as emergency measures
  • Construction of Eastern and Western Peripheral Expressways
    • To provided fast alternative routes to vehicles not destined for Delhi.

2) STUBBLE BURNING – CLASS DISCUSSION

A) PUSA DECOMPOSER

• a technology developed by IARI to manage paddy stubble in fields. It can rapidly degrade paddy straws in the field and convert them into compost, which then doesn’t pose any issues for sowing of wheat crops, as per IARI scientists.
  • It contains seven strains of fungi, which is to be mixed with water, 150 gms of jaggery and 50 gms of besan, to prepare a 25-litre solution that can be sprayed on 1 hectare of field.
  • Results: Farmers of north Delhi found in 2020 that PUSA decomposer took about 20-22 days for stubble to decompose. This has helped in increasing soil fertility (less fertilizer use) and reduced the need of extensive ploughing to mix stubble with soil.

 3) FIRE CRACKERS

• Introduction
  • Firecrackers are among the most poisonous air pollutants. The chemical footprint left by them have a devastating impact on human health and especially affects children.
  • CPCB in a study in Delhi in 2016 found that the levels of Aluminium, Barium, Potassium, Sulphur, Iron and Strotium rose sharply in Diwali night, from low to extremely high.
• Science behind Firecrackers
  • Firecrackers use fuel and oxidizers to produce a combustion reaction, and the resulting explosion spreads the material in a superheated form. The metal salts in the explosive mix get ‘excited’ and emit light. Metals in the mix, which have varying arrangement of electrons in shells outside their nucleus, produce different wavelength of light in this reaction, generating spectacular colors.
    • For e.g. Barium compounds produce green light, Strontium and lithium salts produce red colors.
• But firecrackers are big health hazards.
  • Chemicals such as barium nitrate and cadmium compounds cause respiratory irritation and gastrointestinal problems.
  • Aluminium sulphide is known to cause Alzheimer’s.
  • Lithium and copper compounds cause hormonal imbalance and so on.
• In order to tackle the air and noise pollution during the festival season, the Supreme Court in a judgment (Arjun Gopal & others Vs Union of India & others), in Oct 2018 have mandated a series of steps to reduce the pollution from firecrackers. The key highlights of the Supreme Court Judgment includes:
  1. Improving the quality of crackers to reduce Air pollution.
     1. Use of reduced emission firecrackers (improved crackers)
        • Avoiding use of ash as filler material -> Reduce particulate matter by 15-20%.
        • Use of charcoal meeting the PESO specifications.
     2. Use of Reduced emission firecrackers (green crackers)
        • To reduce emission of PM, NOx, and SO2 due to in-situ water generation as dust
     3. Firecrackers only with permitted chemicals to be allowed -> PESO shall test and check for the presence of banned chemicals like lithium/arsenic/antimony/lead & mercury.
     4. Banning of Barium salts in Firecrackers
        1. Barium emits poisonous gas causing respiratory problems and may have health complications due to long-term exposure.
        2. Why Barium so common in firecrackers emits green light, low cost, readily available.
     5. Enough facilities should be created to ensure use of quality raw material in gun/flash powder as per the Petroleum and Explosives Safety Organization (PESO) specifications. This will address the issue of high content of unburnt/partially combusted material.
     6. PESO to ensure firecrackers satisfy decibel levels
  2. Time Limit
     • Firecrackers are only allowed from 8-10 pm in Diwali and 55 pm – 12.30 pm in Christmas and New year.
  3. Blanket ban on online sale
  4. Ban on series cracker (‘laris’).
  5. Stations house officer will be held liable for contempt of court in case of violation of any judgment.

4) GREEN CRACKERS

• What are Green Crackers?
  • Green Crackers are firecrackers produced using less harmful raw materials and additives to reduce emissions.
    • CSIR-NEERI has defined Green crackers as those which will reduce emission by 30% and can limit sound to 125 decibels (at a distance of 5 meters).
    • Since the Supreme Court had banned barium nitrate, the green chemicals contain Potassium nitrate and zeolite in green crackers instead.
    • They newly developed crackers also include Safe Water Releaser, Safe Minimal Aluminum Cracker and Safe Thermite Crackers.
      • The additives in Safe Water Releaser give out water, air and dust suppressants.
      • The Safe Minimal Aluminium minimizes the use of aluminium, potassium nitrate and sulfur.
      • The Safe Thermite Cracker is based on a combination of metals, including aluminium, and metal oxides like iron oxides to produce heat.
    • The packaging of these crackers contains a QR code and a green logo that states that they have been certified by CSIR and NEERI.
• Supreme Court in Nov 2019 has said that it wants every consignment of the material used in manufacturing green fire crackers to be tested for quality control.
  • Quality control mechanism should be set up in each manufacturing unit of green fire crackers within 15 days and such units be monitored by officials from the Petroleum and Explosive Safety Organization (PESO).
• Are Green Crackers completely Green?
  • No
  • They produce 30% less PM2.5 and 50% less SO2 emissions. But they still produce PM2.5 and SO2.

 5) SMELTING INDUSTRY AND POLLUTION

• Smelting is a metallurgical process that involves heating raw ore or metal in order to extract or refine a desired metal.
  • The process involves use of high temperatures and chemicals to break down the ore, allowing the desired metal to be separated from the other materials in the ore or metal.
  • Generally, the raw material is usually heated to a high temperature in a furnace, along with a reducing agent such as coke or charcoal, which helps to reduce the metal oxide in the ore or metal to a pure metal.
• Smelting is used in the extraction of metals like iron, copper, lead and zinc as well as in the production of alloys such as steel.
• Smelting is also a major source of Pollution:
  • It releases large amounts of pollutants such as sulfur dioxide and heavy metals into the air, water, and soil. The industry also causes noise pollution.

 6) ODOUR POLLUTION

• Introduction
  • World Health Organization recognizes Odour (unpleasant smell) as a pollution and says it affects the quality of life and social well-being of individuals. The unpleasantness is created by presence of compounds such as Ammonia, Hydrogen Sulphide, butyric acid, ethyl and methyl mercaptan and dimethyl Sulphide.
  • Impact: It may lead to vomiting, headaches, nausea, stress, anxiety, frustration, restriction in outdoor activities, children unable to sleep and discomfort for elderly and others.
• Main Sources of Odour Pollution
  • MSW dumpyards, oil refineries, fish markets, slaughterhouses, distilleries, pharmaceuticals, biomedical and hazardous waste disposal sites and pesticide plants.
• Steps Taken
  1. Central Pollution Control Board (CPCB) issues detailed guidelines for proper Monitoring and Management of Odour at Urban Municipal Solid Waste Landfills (Sep 2017)
     • The guidelines were based on the ‘scientific pilot study‘ of East Delhi’s Ghazipur landfill
     • Buffer zones: Green Belt around land fill sites and suggested selection of appropriate plant species for vegetation cover to assist in reducing odour.
     • Trapping LFG gases: MSW landfill sites should be designed to tap landfill gases (LFG) efficiently to mitigate fugitive odorous emissions.
     • Legislative norms on baseline data: The guidelines also suggested for initiating legislative norms for creating baseline data on odour.
     • Need for gradual shift for installation of Continuous Odour Measurement Systems (Sensor based) similar to Continuous Air Quality Monitoring Stations (CAAQMS).
       • This is needed as manual measurement is time consuming
     • Various Considerations before choosing landfill sites
       • Present population and projected growth for the next 20 years
       • Whether the selected site is free from the impact of other odorous sources and the topography of the site (slope, proximity to water sources like river and natural springs)
       • Selection should be integrated with the urban development plan of the city so that even expansions of the city in next two or three decades are not encompassing the selected MSW site

 2. VARIOUS AIR QUALITY MEASURING INITIATIVES IN INDIA

 1) NATIONAL AIR QUALITY MONITORING PROGRAMMES (NAMP)

• CPCB is executing a nation-wide program of ambient air quality monitoring known as National Air Quality Monitoring Program (NAMP).
• Objective of NAMP is:
  1. To Determine status and trends of ambient air quality
  2. To Ascertain whether the prescribed air quality standards are violated
  3. To obtain the knowledge and understanding necessary for developing preventive and corrective measures
  4. To understand the natural cleansing process undergoing in the environment through pollution, dilution, dispersion, wind-based movement, dry deposition, etc.

• ­Pollutants covered:
  1. Under NAMP, four air pollutants , Sulphur dioxide (SO2), Oxides of Nitrogen (NO2), Respirable Suspended Particulate Matter (RSPM/ PM10), and Fine Particulate Matter (PM 2.5) have been identified for regular monitoring at all the locations.
  2. The monitoring of meteorological parameters such as wind and wind direction, relative humidity (RH) and temperature were also integrated with the monitoring of air quality.

2) NAAQS (NATIONAL AMBIENT AIR QUALITY STANDARDS) BY CPCB

• Ambient Air Quality refers to the condition or quality of air surrounding us in the
• NAAQS are the standards for ambient air quality set up by CPCB and are applicable
  • The CPCB has been conferred this power by the Air (Prevention and Control of Pollution) Act, 1981.
• The current standards were set up in 2009 and were an improvement over previous It covers 12 pollutants:
  • CO, SO2, NOx, PM10, PM2.5, Ozone, NH3, lead, Arsenic, Benzene, Benzopyrene, Nickel.

3) AIR QUALITY INDEX (AQI)

• Air Quality Index is a number used by government agencies to communicate to the public how polluted the air quality is or how polluted it is forecasted to become.
• In India, National Air Quality Index, was launched in Sep 2014 as part of Swachh Bharat Abhiyan by MoEF&CC.
• The CPCB, the nodal agency for air pollution data in India, has developed a color coded air-quality index to mark hazardous levels for the public benefit.
• There are six AQI categories, namely Good, Satisfactory, Moderately polluted, Poor, Very Poor, and servere.
• It considers 8 pollutants (PM10, PM5, NO2, SO2, CO, O3, NH3, and Pb.)
• Initially it was launched in 10 cities and today it covers 24 cities in 10 states.