Noise and air pollution during Covid-19 lockdown easing around a school site

Area of Science:

• Environmental Science
• Atmospheric Science
• Public Health

Background:

• The Covid-19 pandemic led to global lockdowns, significantly reducing road traffic.
• This reduction in traffic resulted in decreased air pollutant concentrations and noise levels.

Purpose of the Study:

• To analyze noise and air pollution data during Covid-19 lockdowns and subsequent easing of restrictions in the UK.
• To explore correlations between noise and air pollutants, variations among pollutants, and factors influencing temporal changes.

Main Methods:

• Examined hourly and daily average noise levels and air pollutant concentrations.
• Analyzed data across five phases of restriction easing in 2021.
• Investigated correlations between noise, air pollutants (PM1, PM2.5, PM10, NO2, O3), and meteorological factors.

Main Results:

• Strong linear correlations observed between particulate matter sizes (PM1, PM2.5, PM10) (0.70 < r < 0.98).
• Inverse correlation found between nitrogen dioxide (NO2) and ground-level ozone (O3) (-0.68 < r < -0.78).
• Noise levels showed weak correlation with air pollutants but moderate correlation with meteorological factors (wind direction, temperature, humidity).
• A significant increase in noise levels (up to 3 dB, p < 0.01) occurred with initial restriction easing, persisting through subsequent phases.

Conclusions:

• Traffic-related air pollutant concentrations are strongly correlated, influenced by factors like NO2 acting as an O3 precursor.
• Noise levels are more influenced by meteorological conditions than traffic-related air pollutants.
• Easing of Covid-19 restrictions led to a sustained and significant increase in urban noise levels.