Lockdowns & Reduced Air Pollution

Why in news?

Lockdowns around the world, enforced to slow down the spread of Covid-19, have also visibly reduced air pollution.

How was the result of reduced pollution quantified?

• Quantification - A new study in ‘Lancet Planetary Health’ has quantified the number of lives saved in China due to reduced pollution.
• It has estimated that 12,125 deaths were prevented during China’s ban on traffic mobility between February 10 and March 14, 2020.
• This is higher than the lives lost to the pandemic - 4,633 as of May 4.
• Applicability - These findings cannot be directly applied to other countries due to the differences in severity of and responses to COVID-19, air pollution levels and population characteristics.
• But the reduction of air pollution levels have been detected in other countries such as South Korea, India, Italy, Germany, Spain, and the US after their own lockdowns.
• This could have likely brought health benefits in those countries, too.
• However, this way of having clean air through massive quarantine and travel restrictions is not sustainable and likely to be only temporary.

What are the calculations?

• The study was conducted in 367 Chinese cities from January 1, 2016 to March 14, 2020.
• The estimates are based on changes in daily concentrations of two air pollutants (nitrogen dioxide and PM2.5).
• The changes in air quality in 2020 (during quarantine versus before quarantine) were calculated.
• These changes were compared these findings with corresponding changes in the same periods (lunar calendar) for 2016 to 2019.
• Accounting for these earlier years helped factor in the already declining pollution levels in China on account of the country’s clean air policy.
• The study calculated the deaths prevented due to reduced levels of these two pollutants.

What are the findings?

• Due to quarantine, nitrogen dioxide dropped by 22.8 micrograms/cubic metre (Wuhan) and 12.9 micrograms/cubic metre (China).
• PM2.5 dropped by 1.4 micrograms/cubic metre (Wuhan) and 18.9 micrograms /cubic metre (China).
• The improved air quality during the quarantine period prevented,
  1. 8,911 nitrogen dioxide-related deaths (65% from cardiovascular diseases and COPD) and
  2. 3,214 PM2.5-related deaths (73% from cardiovascular diseases and COPD).

What is the takeaway?

• As aggressively as we are fighting Covid19, we must reduce air pollution and address climate change.
• However, this should be done in a more sustainable and healthier way.
• This can prevent the health burdens of air pollution and climate change without having the devastating consequences of a pandemic.
• We need to build a more sustainable and climate-friendly society.
• This will require strong political will, enhanced international cooperation, and unprecedented societal mobilization.

Source: The Indian Express