Emission estimates and air quality simulation on Lombardy during lockdown

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Air Quality Management

Background:

• The COVID-19 pandemic necessitated unprecedented public health measures, including lockdowns, which significantly altered human activities.
• Understanding the environmental impact of these lockdowns on air quality is crucial for future policy-making and public health strategies.

Purpose of the Study:

• To quantify daily variations in major air pollutant emissions during the anti-COVID-19 lockdown in Lombardy (February-May 2020).
• To assess the impact of these emission changes on air quality concentrations using advanced modeling techniques.

Main Methods:

• Developed a methodology for emission estimates in Lombardy, later extended to the Po-basin and Italy.
• Combined air emission inventory data with temporal and spatial variation indicators for daily emission calculations.
• Utilized the FARM chemical and transport model to simulate air quality impacts and secondary particulate matter formation.

Main Results:

• Significant reductions in nitrogen dioxide (NO2) concentrations were observed.
• Variations in particulate matter (PM10) averages were slight.
• An increase in domestic heating emissions partially offset reductions from decreased road traffic.
• Simulations indicated a potential increase in tropospheric ozone levels.

Conclusions:

• The study demonstrates a clear link between lockdown measures, emission changes, and subsequent air quality variations.
• The methodology developed provides a framework for assessing the impact of large-scale societal changes on air pollution.
• Findings highlight the complex interplay of different emission sources and their non-linear effects on atmospheric chemistry.