India's Environment: Post-Covid-19 Pollution Levels

The COVID-19 pandemic has had a significant impact on the environment, with air pollution decreasing in many parts of the world. India, which is home to some of the world's most polluted cities, has seen a noticeable reduction in smog and air pollution due to the lockdown restrictions. With people staying at home, factories closed, and a decrease in air traffic and road traffic, air pollution levels have dropped significantly. According to studies, the concentration of particulate matter (PM) 10 decreased by around a third to a fourth of pre-pandemic levels in India. While the environmental impact of the pandemic is temporary, the short-term effects on air quality in India have been striking.

Air quality improved during the COVID-19 lockdown

India has long struggled with air pollution, with six out of ten of the world's most polluted cities in 2020. The COVID-19 lockdown, which restricted the operation of various sectors in the country, had a significant impact on improving air quality across major Indian cities.

The lockdown encompassed 1.3 billion people, with traffic virtually non-existent, factories closed, and construction halted. This led to a noticeable reduction in smog and air pollution. The Centre for Pollution Control (CPCB) discovered that the number of cars on the road decreased, contributing to a 51% reduction in nitrogen oxide (NOx) levels and a 32% decrease in carbon dioxide (CO2) levels.

According to the Central Pollution Control Board's database, air quality monitoring station statistics showed an overall improvement in air quality across major Indian cities. The air quality data, collected from 30-12-2019 to 28-04-2020, utilized 231 automatic air quality monitoring stations in a major Indian metropolis. The data revealed improvements in air quality parameters such as PM 2.5, PM 10, CO, NO2, SO2, O3, and AQI during and before the COVID-19 lockdown periods.

Furthermore, industrial activities, including stone extraction and crushing for construction, slowed down or stopped during the lockdown. Surface air measurements confirmed a significant drop in air pollution levels. One study found that the concentration of particulate matter (PM) 10 decreased by around a third to a fourth of pre-pandemic levels.

While the COVID-19 lockdown improved air quality in India, experts believe these gains are temporary. As socio-economic activities resume post-lockdown, air pollution levels are expected to rebound. Nevertheless, the short-term effects of the lockdown on air quality were striking, providing a glimpse of the potential benefits of reduced emissions and improved air quality.

Industrial activities slowed or stopped

India has long struggled with high levels of pollution. In February 2020, India was home to six out of ten of the world's most polluted cities. However, the COVID-19 lockdown restrictions slowed or halted many industrial activities in the country.

The Indian government ordered a 21-day lockdown starting on 25 March 2020, encompassing 1.3 billion people. This lockdown kept people at home, closed factories, and halted construction, leading to a noticeable reduction in smog and air pollution.

The Center for Pollution Control (CPCB) released a report on the air quality effects of the lockdown, discovering that the decrease in the number of cars on the road contributed to a significant drop in nitrogen oxide levels (51%) and carbon dioxide levels (32%) between 22 and 23 March 2020.

Satellite images and data from NASA's Landsat 8 also showed a reduction in environmental pollution during the lockdown period. One study found that the concentration of an air pollutant called particulate matter (PM) 10 decreased by around a third to a fourth of pre-pandemic levels in India.

While the environment may have experienced a temporary respite during the pandemic, experts believe that pollution levels will rebound once restrictions are lifted.

Fewer cars on the road

India has long struggled with high levels of pollution. In February 2020, India was home to six of the world's ten most polluted cities. However, the COVID-19 lockdown restrictions imposed on the country's 1.3 billion people have resulted in a notable decrease in pollution.

One of the key factors contributing to the reduction in pollution is the decrease in road traffic. With people staying at home, there are fewer cars and buses on the roads. This has led to a significant drop in nitrogen oxide levels. According to the Center for Pollution Control (CPCB), there was a decrease of up to 51% in nitrogen oxide levels (NOx) and a 32% decrease in carbon dioxide (CO2) levels during the lockdown. The reduction in vehicles on the roads has also contributed to the overall improvement in air quality across major Indian cities.

The impact of reduced traffic on pollution levels is not limited to India. In Los Angeles, for example, nitrogen levels dropped significantly, and rush-hour traffic virtually disappeared during the lockdown. This led to a noticeable improvement in the city's air quality and a clearer skyline. Similar effects were observed in other parts of the world, such as the Philippines' capital city, where fine particulate matter—the world's deadliest air pollutant—dropped by 180% during the quarantine period.

While the short-term effects of the lockdown on pollution levels are striking, experts believe that these improvements may not last once the restrictions are lifted. However, the lockdown has provided a glimpse of the potential for improved air quality and a healthier environment if emissions are reduced. It highlights the importance of long-term goals and sustainable process improvements to achieve high air quality standards and mitigate the impact of pollution on public health.

Factories closed

India has long struggled with air pollution, with six out of ten of the world's most polluted cities in 2020. The COVID-19 lockdown in India encompassed 1.3 billion people, creating the world's largest lockdown. With so many people at home, industrial activities, including factories and construction projects, slowed or came to a complete stop. This led to a noticeable reduction in smog and air pollution.

The Central Pollution Control Board's database of air quality monitoring station statistics showed an overall improvement in air quality across major Indian cities. The concentration of an air pollutant called particulate matter (PM) 10 decreased by around a third to a fourth of pre-pandemic levels. There was also a significant improvement in air quality levels when compared to the same time period in the previous year.

The decrease in the number of cars on the road contributed to a decrease of up to 51% in nitrogen oxide (NOx) levels and a 32% decrease in carbon dioxide (CO2) levels. Industrial operations also contributed to this decrease in nitrogen oxide output.

While the environment may be recovering during the pandemic, experts don't expect this to last. However, the short-term effects are significant, and it provides an opportunity to focus on reducing emissions at the source and achieving long-term improvements in air quality.

Experts don't expect the changes to last

India has some of the worst air pollution in the world, resulting in a disproportionately high level of mortality and disease. The country's first COVID-19 lockdown, which began on 25 March 2020, saw a reduction in major urban sources of air pollution, such as traffic, industry, and construction. Observational data shows air pollution in India decreased drastically in the first COVID-19 lockdown, when emissions from vehicles naturally declined. However, York University researchers say that these numbers only tell part of the story.

While the lockdown in India reduced urban sources of air pollution, it also gave researchers an opportunity to study the contribution of local sources of air pollutants during normal meteorological conditions. York University postdoctoral researcher Leigh Crilley, who led the Faculty of Science research, stated that to accurately quantify the impact of the COVID-19 lockdown on air pollutant levels, meteorology and atmospheric chemistry need to be considered in addition to emissions. Crilley and her team found that the decline in local emissions had less influence on the decrease in air pollutants than first thought.

The researchers discovered that some air pollutants didn't drop nearly as much as initially thought, and, surprisingly, ozone levels increased even as other pollutants decreased. The air looked much cleaner, allowing more sunshine to get through and creating conditions for ozone (O3) to increase by up to 30%. The paper, titled "Importance of meteorology and chemistry in determining air pollutant levels during COVID-19 lockdown in Indian cities", was published in the journal Environmental Science: Processes & Impacts.

The lockdown also impacted water quality in India. Due to the shutdown of anthropogenic activities, improvements in coastal water quality were observed along the west coast of India and in the Hooghly estuarine region in the northern Bay of Bengal. The Ganga also experienced significant improvements in water quality, with DO levels increasing and BOD and nitrate concentrations decreasing. However, these improvements are expected to be temporary, as levels of pollution will likely rebound once restrictions are lifted.

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