How changes in human activities during the lockdown impacted air quality parameters: A review.

Area of Science:

• Environmental Science
• Public Health
• Atmospheric Chemistry

Background:

• The COVID-19 pandemic necessitated global lockdowns, drastically altering industrial, logistical, and daily human activities.
• These unprecedented restrictions had significant, yet largely unquantified, consequences for environmental quality, particularly air quality.

Purpose of the Study:

• To critically review and synthesize recent scientific literature on the impact of COVID-19 lockdowns on human activities and air quality.
• To evaluate changes in air pollutant concentrations during the initial lockdown periods of 2020 compared to historical data.

Main Methods:

• Systematic review and critical evaluation of existing scientific publications.
• Analysis of reported air quality data, focusing on key pollutants before and during lockdown periods.

Main Results:

• Significant reductions observed in concentrations of particulate matter (PM), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO) during the 2020 lockdown.
• A notable increase in tropospheric ozone (O3) levels was recorded, contrasting with the decrease in other pollutants.
• The findings highlight a clear correlation between reduced human activity and improved air quality metrics, with exceptions like ozone.

Conclusions:

• The COVID-19 lockdown provided critical data demonstrating the direct link between emission reductions and air quality improvements.
• These insights are crucial for informing future environmental policies and strategies for sustainable industrial, logistics, and mobility sectors.
• The study underscores the potential for strategic interventions to enhance environmental sustainability in key economic sectors.