Air Pollution In India: Understanding The Crisis

India is one of the world's most polluted countries, with 21 of the world's 30 most polluted cities. The country's rapid economic growth has been accompanied by a range of environmental challenges, including air pollution. India's air quality issues are multi-sectoral and multi-jurisdictional, with emissions from vehicles, industry, thermal power plants, construction, and the burning of wood and dirty fuels for cooking and heating all contributing to poor air quality. The capital, New Delhi, is the world's most polluted capital city, with air pollution levels nearly ten times higher than World Health Organization guidelines. The city's geography, with surrounding mountains trapping pollutants, exacerbates the problem. India's air pollution has severe health and economic impacts, causing approximately 2 million deaths annually and resulting in economic losses of up to $36.8 billion in 2019. While the country has launched initiatives like the National Clean Air Program to reduce particulate matter pollution, air quality remains a critical issue requiring effective strategies and enforcement across various sectors.

Industrial and vehicular emissions

India is the fourth-largest emitter of greenhouse gases, contributing 7.08% of global emissions. It has the third-worst air quality in the world, and 13 of its North Indian cities are among the 15 most polluted cities globally. Transportation is a significant contributor to this problem. The transport sector accounts for a quarter of India's total emissions, with road transport accounting for three-quarters of that amount. Vehicular emissions are a major cause of air pollution in urban areas, contributing 20-30% of particulate matter (PM) 2.5 at the breathing level of air quality.

Vehicles contribute about 290 gigagrams (Gg) of PM2.5 annually, and 8% of India's total greenhouse gas emissions come from the transport sector. In Delhi, this figure exceeds 30%. Indian cities like New Delhi, Bangalore, Mumbai, and Kolkata have some of the highest sources of NOx in the country, which is linked to vehicular pollution. An excess of NOx leads to ground-level ozone, which is associated with respiratory diseases and asthma. Particulate matter (PM) includes solid and liquid pollutants such as dust, soot, and smoke, which are easily inhaled. The transport sector contributes to a third of India's PM pollution and 20-35% of PM 2.5 pollution in urban areas.

Traffic congestion in Indian cities and towns is severe, leading to lower average trip speeds. This results in higher emissions, as vehicles burn fuel inefficiently at low speeds. For example, when average speeds are between 5 and 20 kilometres per hour, pollutant emissions can be up to eight times higher than at speeds between 55 and 70 kilometres per hour. Traffic gridlock in cities like Delhi causes a build-up of local pollution, especially under stagnant conditions.

Fuel adulteration is also a significant issue in India. To save money, some taxi and auto-rickshaw drivers blend cheaper hydrocarbons with highly taxed hydrocarbons like gasoline and diesel. This practice increases tailpipe emissions of harmful pollutants, including hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOx), and particulate matter (PM). Adulterants like kerosene also result in higher levels of HC, CO, and PM emissions, even in catalyst-equipped cars. Additionally, the higher sulfur content of kerosene is a concern.

The Indian government has taken steps to address vehicular emissions. The Bharat Stage (BS) emission standards regulate air pollutants from internal combustion engine and spark-ignition engine equipment, including motor vehicles. From April 2020, vehicle manufacturers were mandated to produce, sell, and register only BS-VI (BS6) vehicles. The government also proposed a gradual rollout of ethanol-blended fuel, with a target of achieving an E10 fuel supply by April 2022 and a phased rollout of E20 from April 2023 to April 2025. Additionally, the government is developing Real Driving Emissions (RDE) procedures, which are expected to come into force in 2023. These procedures will account for various conditions, including altitudes, temperatures, vehicle payloads, and road types, to better reflect real-world driving emissions.

Construction dust and debris

The mixing of concrete, for instance, is estimated to contribute to 10% of coarse pollutants in Delhi's air. Other construction activities, such as excavation, demolition, earth filling, material transportation, and vehicle movement on unpaved roads, also generate high levels of dust emissions. Poor building standards and outdated practices further exacerbate the problem.

The impact of construction dust is evident in the air quality of Indian cities. In Mumbai, construction dust accounts for 71% of particulate matter, while in Delhi, dust kicked up by cars on roads contributes between a third and 56% of the city's most harmful pollutants. During winter in northern India, severe spikes in air pollution occur due to a mix of local and transboundary pollutants combined with meteorological conditions.

To address this issue, the Indian government has implemented various measures. The Commission for Air Quality Management (CAQM) has introduced the Graded Response Action Plan (GRAP) in Delhi NCR to regulate pollution levels. This plan targets high-polluting sectors, including construction, and imposes restrictions on their activities during periods of high pollution. The government may enforce the use of anti-smog guns, water sprinklers, and dust suppression measures at construction sites. In severe cases, blanket bans on construction activities may be imposed. Additionally, the government launched a web portal for construction project proponents to self-monitor and report compliance with dust control guidelines, allowing for easier enforcement and the imposition of fines for violations.

Furthermore, strategic planning is essential to mitigate the negative impacts of construction bans. Effective dust mitigation measures must be incorporated into project schedules from the outset. This includes the use of water sprinklers, anti-smog guns, dust suppressants, covering materials, and installing barriers. Implementing these measures can result in a significant reduction in PM concentration levels, as seen in the Council on Energy, Environment and Water's (CEEW) pilot study in Gurugram.

Dependence on thermal power

India's dependence on thermal power is a significant contributor to its air pollution crisis. Thermal power plants emit harmful pollutants such as PM2.5, sulphur dioxide, nitrates, and heavy metals, which have severe impacts on human health and the environment. Coal-fired power plants account for around 47% of India's electricity generation capacity, and coal-based power is predicted to increase in the coming years, indicating a continued reliance on this energy source.

The emissions from thermal power plants are not adequately addressed in India's clean air programmes, with less than 1% of funds directed towards controlling these emissions. While compliance norms for emissions from thermal power plants were introduced in 2015, the deadlines for installing the necessary technology to reduce emissions, such as FGD (flue-gas desulfurization), have been repeatedly extended. The lack of enforcement and understanding of the importance of FGD technologies among stakeholders has led to a lax approach to compliance.

The Central Pollution Control Board (CPCB) has acknowledged that the 2015 emission standards, if implemented, could have significantly reduced NOX, SOX, PM, and mercury emissions from thermal power plants. However, the focus has often been on greenhouse gas emissions rather than these specific pollutants. The CPCB has also faced challenges due to a lack of data and tracking of certain emissions, particularly SOX and NOX, in the past.

The health risks associated with exposure to pollutants from thermal power plants are significant. Studies have shown that prolonged exposure to heavy metals released from these plants can lead to neurological and renal disorders, endocrine disruption, cancer, hypertension, and cardiovascular issues. The total premature mortality attributable to pollution from coal power plants is expected to increase annually, with a projected growth of 2-3 times by 2030.

In addition to the health impacts, thermal power plants also contribute to environmental degradation. Fly ash, a byproduct of coal combustion, is often not appropriately managed, leading to soil, surface water, and groundwater pollution. Despite utilization in some sectors, such as cement manufacturing and road embankments, the improper disposal of fly ash in landfills remains a major concern.

Addressing India's dependence on thermal power and the resulting air pollution requires a multifaceted approach. This includes enforcing stricter emission regulations, adopting cleaner energy sources, improving the management and utilization of coal combustion byproducts, and transitioning to advanced technologies for reducing emissions.

Waste burning

Open waste burning is expected to become the largest source of these pollutants by 2035. The burning of garden waste is a common occurrence across many Indian cities, with up to 4% of municipal solid waste (MSW) burned in the open daily. This not only contributes to air pollution but also points to inefficiencies within the waste management system.

India is the world's largest consumer of fuelwood, agricultural waste, and biomass for energy purposes. The use of traditional fuels, such as fuelwood, crop residue, and dung cakes, dominates domestic energy use in rural India, accounting for about 90% of total energy consumption. In urban areas, traditional fuel use constitutes about 24%. India burns ten times more fuelwood annually than the United States, and the less efficient Indian stoves produce more smoke and air pollutants per kilogram.

To address waste burning, India has implemented initiatives such as the National Clean Air Programme (NCAP), which aims for a 20-30% reduction in PM2.5 and PM10 concentrations by 2024. Additionally, decentralized waste management systems at the community and ward levels can reduce the likelihood of dumping and burning, lower transport costs, and create job opportunities for informal workers. Promoting cleaner alternatives, such as LPG, for cooking and heating can also help reduce waste burning and improve indoor air quality.

Fuelwood and biomass burning

The burning of fuelwood and biomass releases carbon-containing gases that are highly reactive and contribute to the formation of particulate matter, such as PM2.5. PM2.5 emissions from biomass burning are tens to hundreds of times higher per kilogram than those from coal power plants or diesel automobiles. This is due to the inefficient combustion of fuelwood and biomass in traditional cookstoves, which are present in over 100 million Indian households. The emissions from these cookstoves are released directly into the air without the benefit of pollution control devices, leading to high levels of indoor and outdoor air pollution.

The health impacts of fuelwood and biomass burning are significant. Studies have linked indoor air pollution from biomass combustion to respiratory health issues, with particular risks for women who cook with these fuels and young children. The World Health Organization (WHO) estimates that 300,000 to 400,000 people die annually in India from indoor air pollution and carbon monoxide poisoning due to biomass burning. Additionally, biomass burning contributes to the formation of the Asian brown cloud, which delays the start of the monsoon season and impacts the region's climate.

To address the air pollution caused by fuelwood and biomass burning, India needs to transition to cleaner energy sources for cooking and heating. Shifting households to LPG, biogas, or electricity for these purposes would eliminate 48% of India's PM2.5 emissions and prevent hundreds of thousands of premature deaths. While this transition presents a significant challenge, focused policy interventions and rigorous monitoring can help achieve this goal and improve air quality in India.

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