Changes in air pollution during COVID-19 lockdown in Spain: A multi-city study

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Public Health

Background:

• The COVID-19 pandemic led to unprecedented global lockdowns.
• Spain implemented a nationwide lockdown from March 15th to April 12th, 2020, due to high mortality rates.

Purpose of the Study:

• To investigate the impact of a short-term COVID-19 lockdown on atmospheric pollutant levels.
• To analyze the influence of meteorological factors on these pollutant levels across 11 Spanish cities.

Main Methods:

• Analysis of atmospheric levels of CO, SO2, PM10, O3, and NO2.
• Comparison of pollutant data from before and during the lockdown period.
• Statistical analysis incorporating meteorological variables like temperature, precipitation, and wind.

Main Results:

• Significant reductions in NO2 levels observed in most cities.
• Decreases in CO, SO2, and PM10 were noted in several urban areas.
• An increase in O3 levels was recorded across the studied cities.

Conclusions:

• The 4-week lockdown effectively reduced several key air pollutants in Spain.
• Meteorological factors play a role in modulating pollutant concentrations.
• The observed increase in O3 warrants further investigation into photochemical reactions during reduced emissions.