India is one of the most populous and fastest-growing countries in the world, but also one of the most polluted. According to a study in The Lancet, air pollution caused nearly 1.6 million deaths in India in 2019 alone. The country's capital, New Delhi, is regularly shrouded in smog, with vehicle emissions, industrial activities, agricultural burning and dust storms contributing to the poor air quality.
Air pollution not only affects human health, but also the environment and the climate. It damages crops, forests, water resources and wildlife. It also contributes to global warming by emitting greenhouse gases and aerosols that alter the radiation balance of the Earth. Air pollution can also affect the monsoon patterns and rainfall distribution in India, which are vital for agriculture and water security.
A recent study published in Nature revealed that India witnessed the worst levels of human-induced air pollution during 2018-2021, a period that spanned the three phases of the COVID-19 pandemic (pre, during and post). The study used machine learning and satellite data to monitor the levels of various air pollutants and chemical components in the atmosphere. It found that the development of transportation, industrial power plants, green space dynamics and unplanned urbanisation led to a surge in air pollution across the country.
The study also identified the hotspots of air pollution in India, such as Delhi, Kolkata, Mumbai, Pune and Chennai. These cities recorded huge fluctuations in terms of air quality index (AQI), nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3), sulphur dioxide (SO2) and methane (CH4). The study noted that these pollutants are associated with various health problems, such as asthma, respiratory disease, lung cancer and skin diseases.
The authors of the study suggested that India needs to adopt a comprehensive approach to monitor and control air pollution at different scales. They recommended using satellite data along with ground-based measurements and models to assess the spatial and temporal variations of air pollution. They also advocated for implementing effective policies and regulations to reduce emissions from various sources and sectors.
India has launched the National Clean Air Programme (NCAP) in 2019 with the aim of reducing particulate matter (PM) pollution by 20-30% by 2024. However, a study by researchers from Indian Institute of Technology Delhi flagged gaps in India's air pollution monitoring system and suggested a new model to improve it. The study found that India has only 250 continuous ambient air quality monitoring stations (CAAQMS) covering 100 cities, which is inadequate to capture the diversity and complexity of air pollution in the country.
The study proposed a new model based on population density, land use patterns, emission sources and meteorology to identify optimal locations for CAAQMS in India. The model suggested that India needs at least 4,000 CAAQMS to cover all its cities and towns. The study also recommended increasing the frequency and accuracy of data collection and dissemination, as well as enhancing public awareness and participation in air quality management.
Air pollution is a serious threat to India's ecology and well-being. It requires urgent action from all stakeholders, including the government, industry, civil society and citizens. By adopting a holistic and scientific approach to monitor and control air pollution, India can protect its environment and its people from its devastating impacts.
One of the most visible effects of pollution is the degradation of air quality. Air pollution causes smog, acid rain, and greenhouse gas emissions that contribute to global warming and climate change. Air pollution also affects the visibility and the quality of sunlight, which in turn affects the photosynthesis and growth of plants. Moreover, air pollution can reduce the rainfall and increase the temperature, leading to droughts and water scarcity. For example, in 2019, Delhi experienced a severe air pollution crisis that reduced the visibility to less than 50 meters and forced schools and offices to close. Another example is the impact of air pollution on the Taj Mahal, one of the seven wonders of the world. The white marble monument has been turning yellow due to the exposure to sulfur dioxide and other pollutants.
Another major impact of pollution is the contamination of water resources. Water pollution occurs when harmful substances such as chemicals, metals, plastics, sewage, and agricultural runoff enter the water bodies such as rivers, lakes, and oceans. Water pollution can cause eutrophication, which is the excessive growth of algae and other microorganisms that deplete the oxygen and kill the aquatic life. Water pollution can also affect the quality and availability of drinking water, as well as the irrigation and hydroelectric power generation. For example, in 2018, a study found that 21 major cities in India would run out of groundwater by 2020 due to overexploitation and contamination. Another example is the plight of the Ganges river, which is considered sacred by millions of Hindus. The river is polluted by industrial effluents, sewage, religious offerings, and human and animal corpses.
A third significant impact of pollution is the loss of biodiversity. Biodiversity refers to the variety and richness of life forms on Earth. India is one of the 17 megadiverse countries in the world, hosting about 8% of the global biodiversity. However, pollution threatens to destroy this natural heritage by altering the habitats and food chains of various species. Pollution can also cause diseases, mutations, and extinctions of wildlife. Some examples of endangered species in India due to pollution are the Bengal tiger, which has lost more than 90% of its habitat due to deforestation and poaching; the Asiatic lion, which is threatened by habitat fragmentation and human-animal conflict; the Indian elephant, which suffers from habitat loss and degradation due to mining and agriculture; and the Ganges river dolphin, which is endangered by water pollution and fishing nets.
So what can we do to protect India's ecology from pollution? There are several measures that can be taken at different levels to reduce and prevent pollution. At the individual level, we can adopt eco-friendly practices such as using public transport or bicycles instead of cars, recycling and reusing materials instead of throwing them away, conserving water and energy at home and work, and planting trees and gardens. At the community level, we can participate in environmental awareness campaigns and activities such as clean-up drives, waste segregation, composting, rainwater harvesting, and solar power generation. At the national level, we can support and demand policies and regulations that limit and monitor the emissions and effluents from industries, vehicles, farms, and households. We can also promote and invest in green technologies and innovations that minimize waste and maximize efficiency.
In conclusion, pollution is a grave threat to India's ecology that requires urgent action from all stakeholders. By understanding the causes and effects of pollution, we can take steps to reduce our environmental footprint and preserve our natural resources for ourselves and future generations.