Air Pollution Measurement Methods In India Explained

Air pollution is a critical issue in India, with 21 of the world's 30 most polluted cities located in the country as of 2019. It is a pressing public health threat, causing approximately 2 million premature deaths annually. India has implemented various initiatives to tackle this issue, such as the National Clean Air Programme (NCAP), which aims to reduce particulate pollution. The country also has real-time air quality monitoring systems, like the India Air Quality Index (AQI), and companies like Prana Air offer pollution monitoring solutions. However, accessing air pollution data from government sources can be challenging, and India's central pollution control board has found that most cities continue to violate air quality standards.

Air Quality Index (AQI)

Air pollution is a critical issue in India, and the country has been taking various measures to combat and monitor it. One of the key tools for measuring air pollution in India is the Air Quality Index (AQI). The AQI is a comprehensive indicator that provides valuable information about the quality of the air we breathe.

The AQI is designed to give a quick and easy-to-understand overview of the air quality at a particular time and place. It takes into account various pollutants, including particulate matter (PM2.5 and PM10), carbon monoxide, ozone, nitrogen dioxide, and sulphur dioxide. By considering the concentration of these pollutants in the air, the AQI provides a numerical value that represents the level of pollution and its potential health risks.

In India, the AQI is monitored by various organisations, including government agencies and private companies. For instance, the Central Pollution Control Board, India's main environmental agency, SAFAR, regularly monitors and reports on the country's air quality. Additionally, companies like Prana Air offer pollution monitoring solutions for various sectors, including real estate, retail, airports, construction, and healthcare.

The AQI is typically categorised into different levels, each indicating a specific range of values and the associated health implications. For instance, an AQI value below 50 is generally considered good, indicating satisfactory air quality. Values between 51 and 100 are moderate, while values between 101 and 150 are unhealthy for sensitive groups, such as people with respiratory conditions. Higher values, such as 151-200, 201-300, and above 300, indicate progressively worse air quality, posing health risks for the entire population.

In recent years, India has made significant efforts to improve its air quality and reduce pollution levels. The National Clean Air Programme (NCAP), launched in 2019, aims to reduce particulate pollution by targeting industrial and vehicular emissions, construction dust, and the use of thermal power. Additionally, local governments have implemented measures such as tighter vehicle emission norms, higher penalties for burning rubbish, and improved control of road dust. These initiatives reflect India's commitment to addressing the pressing issue of air pollution and improving the health and well-being of its citizens.

Meteorological parameters

India has been suffering from some of the worst air pollution in the world. In 2019, the Indian government declared a "war against pollution" and launched its National Clean Air Programme (NCAP), aiming to reduce particulate pollution. The Central Pollution Control Board (CPCB), along with the State Pollution Control Boards (SPCBs), runs the most extensive monitoring network in the country under the National Air Quality Monitoring Program (NAMP). As of 2019, NAMP operates over 750 manual monitoring stations that publicly archive annual average concentrations of PM10, PM2.5, SO2, and NO2. CPCB also archives publicly available, real-time data every 15 minutes from over 220 stations across India, measuring an extensive list of criteria and non-criteria air pollutants and meteorological variables.

The impact of meteorological parameters on air pollution is complex and dynamic. For instance, while higher wind speeds generally aid in dispersion, specific wind patterns or local topography might create air pockets or inversions that trap pollutants near the surface. Additionally, atmospheric stability, influenced by temperature gradients and pressure systems, affects the vertical mixing of pollutants. In stable atmospheric conditions, pollutants can become trapped in a layer of air, leading to the formation of smog or haze. Conversely, unstable conditions promote vertical mixing, dispersing pollutants upwards and reducing their ground-level concentrations.

The inclusion of meteorological parameters in air pollution measurements is essential for several reasons. Firstly, it aids in interpreting air pollution data by accounting for natural variations in pollutant dispersion. Secondly, it helps identify critical periods for pollution control, such as stable atmospheric conditions that warrant more stringent emission reduction measures. Lastly, meteorological data enables the development of air quality forecasts and warnings, allowing authorities to proactively implement measures to mitigate potential pollution episodes and protect public health.

National Clean Air Programme (NCAP)

In 2019, India declared a "war against pollution" and launched its National Clean Air Programme (NCAP), aiming to reduce particulate pollution. This programme was launched in response to air pollution becoming the largest environmental risk to health in the country, causing around 7 million deaths annually, according to the World Health Organization (WHO). Both ambient (outdoor) and household (indoor) air pollution are harmful to health, with major contributors being industry, transportation, coal power plants, and household solid fuel usage.

NCAP's original goal was to reduce particulate pollution by 20-30% nationally relative to 2017 levels by 2024. The focus was on 102 cities that were not meeting India's national annual PM5 standard, termed "non-attainment cities." However, in 2022, the Indian government revised its target, setting no national goal but increasing its ambition at the city level. The new goal aims for a 40% reduction relative to 2017 levels for an expanded group of 131 non-attainment cities by 2025-2026.

If the revised target is met, the annual average PM2.5 exposure in these cities would be 21.9 µg/m3 lower than the 2017 levels. This would have a significant impact on the life expectancy of Indians living in these cities, adding an estimated 2.1 years to their lives. To facilitate the achievement of these targets, India has developed a National Multisectoral Action Plan. This plan includes policies and programmes to address both ambient and household air pollution comprehensively.

One such programme is the Pradhan Mantri Ujjwala Yojna, which aims to improve access to clean energy options like LPG at the household level for marginalised sections of society. Additionally, policies supporting cleaner transport, energy-efficient housing, power generation, and better municipal waste management can effectively reduce key sources of ambient air pollution. While India has taken significant steps to address air pollution through NCAP, accessing air quality data from government sources can be challenging, requiring pre-processing before it is ready for analysis. Making these datasets more accessible and timely would enable Indian citizens with diverse skill sets to actively participate in tackling this critical public health issue.

Health impacts

Air pollution is a pressing public health threat in India, causing a high burden of death and disease. In 2019, 1.67 million deaths were attributed to air pollution in the country, accounting for 17.8% of total deaths. The economic losses due to premature deaths and morbidity from air pollution were US$28.8 billion and $8 billion, respectively, in the same year.

The health impacts of air pollution in India are significant and far-reaching. Both short-term and long-term exposure to air pollution have been linked to increased disease burden, mortality, and reduced life expectancy. The most harmful pollutant, PM 2.5, is a fine particulate matter with a diameter of less than 2.5 microns. It can cause deadly illnesses such as lung cancer, stroke, and heart disease. Other pollutants include particulate matter, carbon monoxide, ozone, nitrogen dioxide, and sulfur dioxide. These pollutants come from various sources, including industry, transportation, coal power plants, and household solid fuel usage.

The impact of air pollution is disproportionately felt by poorer people in India. Those working in construction, factories, and unhygienic environments are more vulnerable to the health effects of poor air quality. They may also be nutritionally and immunologically compromised, further exacerbating the impact of air pollution on their health. Long morbidity due to air pollution impacts their earnings, as they lose productivity at work and incur healthcare expenses.

Recognizing the severity of the issue, India's Parliament approved a law in August 2021 to establish the Commission of Air Quality Management in the National Capital Region and adjoining areas. This step demonstrates the government's commitment to addressing the public health crisis caused by hazardous levels of air pollution. Additionally, India has taken several measures to tackle air pollution, including the National Clean Air Programme (NCAP), which aims to reduce particulate pollution. The government has also implemented programs like the Pradhan Mantri Ujjwala Yojna to improve access to clean energy options for marginalized sections of society. These initiatives reflect India's efforts to mitigate the health impacts of air pollution and improve the quality of life for its citizens.

Pollution sources

India is one of the most polluted countries in the world. In 2019, India declared a "war against pollution" and launched its National Clean Air Programme (NCAP), aiming to reduce particulate pollution.

The main sources of air pollution in India include:

Residential Sector

Burning solid fuels like firewood, fuelwood, agricultural waste, dung cakes, and biomass in homes for cooking, heating, and other purposes is the leading source of ambient particulate pollution in India. Household air pollution contributes to higher levels of total PM2.5 exposure than coal burning, open burning, and transportation. In rural areas, much of the pollution stems from biomass burning for cooking and keeping warm. Traditional fuel dominates domestic energy use in these areas, accounting for about 90% of the total.

Power Sector

Power emissions are the second-largest contributor to air pollution in India. The burning of coal for power generation releases SO2 and NOx emissions. India's massive industrialization has impacted its air pollution levels, with unregulated small-scale industries burning biomass, plastic, and crude oil, releasing various toxic pollutants.

Industrial Sector

Industrial emissions account for about 51% of total air pollution in India. Industrial pollution includes emissions from vehicles and construction dust and debris. India's low per capita emissions of greenhouse gases contrast with the country's high overall emissions as the third-largest producer of greenhouse gases globally.

Transportation Sector

Vehicle emissions are a significant contributor to air pollution in India, accounting for 27% of total pollution.

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