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Post-Diwali burning of fire-crackers, Indian cities are facing severe deterioration in air quality. Delhi recorded its worst air quality of the year on the morning after Diwali as the pollution level entered ‘severe-plus emergency’ category. The overall Air Quality Index (AQI) was estimated at 805.

Delhi is neither an exception nor the Diwali night; as winter sets in the northern Indian states are engulfed under thick haze causing huge disruptions in normal life and in the communication system. Trains and flights are either cancelled or run late causing huge economic loss.

This is disturbing, especially, after the news that air quality across the world is improving. Earth’s protective ozone layer that protects us from the sun’s harmful radiation is healing from damage caused by aerosol sprays and coolants, a new United Nations report said.

According to the UN study, ‘Scientific Assessment of Ozone Depletion: 2018’, the upper ozone layer above the Northern Hemisphere should be completely repaired by the 2030s and the gaping Antarctic ozone hole should disappear by the 2060s.

The UN report claims that this is due to internationally agreed actions carried out under the Montreal Protocol that came into being some 30 years ago in response to the revelation that chlorofluorocarbons (CFCs) and other ozone-depleting elements were tearing a hole in the ozone layer and allowing dangerous ultraviolet radiation to flood through.

Air pollution in Indian cities turns severe to severe-plus emergency category

These are good news. For, as many as nine in 10 people on earth breathe highly polluted air, and more than 80% of urban inhabitants endure outdoor pollution that exceeds health standard according to WHO’s World Global Ambient Air Quality Database.

But even among countries suffering from air pollution, India stands out as one that is consistently witnessing degradation in air quality. With daily averages already in the “very unhealthy” range, 2018 seems set to continue with the same pattern.

Air pollution is a growing risk factor for ill health in India, contributing significantly to the country’s burden of disease. As per the Global Burden of Disease comparative risk assessment for 2015, air pollution exposure contributes to approximately 1.8 million premature deaths and 49 million disability adjusted life-years lost, ranking it among the top risk factors for ill health in India. Home to 10 of the top 20 cities with the highest annual average levels of PM2.5 as per the WHO Urban Ambient Air Quality Database (2016), and with several studies showing a worsening trend over time, it is argued that rapid urbanisation and industrial development have adversely affected urban air quality due to vehicular and industrial emissions.

While the environment, health and development are frequently pitted in adversarial roles in the discourse on economic growth, published evidence find that they are very much in consonance. A study published by the World Bank in 2016 revealed that air pollution cost in India is approximately 8% of its GDP or $560 billion in 2013, as a result of lost productivity due to premature mortality and morbidity.

In order to combat air pollution it is required to identify the pollutants, its source of emission, and investigate the effects of living and the environment. The Central Pollution Control Board has been entrusted to do this. Central Pollution Control Board initiated National Ambient Air Quality Monitoring (NAAQM) programme in the year 1984 with seven stations. The programme was renamed as National Air Quality Monitoring Programme later and the number of stations under operation has been further raised to 503 distributed in 209 cities, 26 states and five Union Territories.

Some of the steps taken by the central and the state governments to control air pollution include formulation of environmental regulations, setting up of monitoring network for assessment of ambient air quality, promotion of cleaner production processes and decision taken to leap-frog directly from BS-IV to BS-VI fuel standards by April 1, 2020. Others include amendments to various waste management rules and revision of existing environmental standards and formulation of new standards for prevention and control of pollution from industries.

In fact as the figures show data collected by Continuous Ambient Air Quality Monitoring Stations indicate that the annual average PM2.5 concentration has come down to 125 micrograms per cubic metre in 2017 compared to  134 micrograms per cubic metre in 2016.

Water pollution worsens due to unplanned urbanisation

India suffers from water pollution too. The largest source of water pollution in India is untreated sewage. Other sources of pollution include agricultural run-off and unregulated small scale industry. Most rivers, lakes and surface water in India are polluted.

Sewage discharged from cities, towns and some villages is the predominant cause of water pollution in India. A study in 2007 found that the major cities of India produce 38,354 million litres per day (MLD) of sewage, but the urban sewage treatment capacity is only 11,786 MLD. A large number of Indian rivers are severely polluted as a result of discharge of domestic sewage. A decade later the situation must have deteriorated further as urbanisation has spread rapidly across the country without corresponding develop-ment in basic civic amenities.

Rivers in India are heavily polluted and have suffered from pollution from multiple sources. In 2017, the government said that 275 of India’s 445 river stretches are polluted. Water from these river stretches were reported to be unfit for consumption and were heavily laden with bacteria and pollutants like zinc and lead. As per Water.org, an international organisation working in the water sector, India’s rivers carry 5% of the world’s waters but an astounding 35% of global sediments.

Cleaning up of India’s rivers, especially the Ganga, has been taken up seriously under the Namami Ganga programme, which has a budget outlay of Rs. 20,000 crore. Cleaning up the river of pollutants and checking sewage disposal in the river are the primary aims of the project.

Excessive use of chemical fertilisers, biocides raise soil pollution

Soil pollution is another environmental hazard that has been growing unchecked in India. The main factors of soil pollution are the high state of soil erosion, excessive use of chemical fertilisers, biocides (pesticides, insecticides and herbicides), polluted liquids and solids from urban and industrial areas, forest fires, water-logging and related capillary processes, leaching, drought, etc.

The accelerated use of chemical fertilisers and biocides in agriculture is the major cause of soil pollution. They are used to increase the yields and to save the crops from insects, pests and unwanted plant growth. It should be particularly noted that biocides first kill germs and unwanted plants and then degrade the quality of soil.

Soil pollution naturally contributes to air pollution by releasing volatile compounds into the atmosphere - so the more toxic compounds soil contains, the greater the air pollution it creates - and can lead to water pollution if toxic chemicals leach into groundwater or if contaminated runoff or sewage, which can contain dangerous heavy metals, reaches streams, lakes or oceans. When applied repeatedly or in large amounts, these heavy metals can accumulate in soils to the point that it is unable to support plant life.

Moreover, soil pollution allows great quantities of nitrogen to escape through ammonia volatilization and denitrification and the decomposition of organic materials in soil can release sulfur dioxide and other sulfur compounds, causing acid rain. Furthermore acidic soils created by the disposition of acidic compounds such as sulfur dioxide brought about by the burning of fossil fuels produce an acidic environment that harms micro-organisms, which improve the soil structure by breaking down organic material and aiding in water flow. Soil pollution may alter plant metabolism and reduce crop yields and cause trees and plants that may absorb soil contaminants and pass them up the food chain.

The growing pollution level in India is a cause of concern, but it is a serious problem across the world. If some environmental pollution is a result of natural causes, most of it is caused by human activities and thus, to control pollution level the world must stop or reduce activities which cause pollution and at the same time, take measures to lessen the level of pollution, which is already there.