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AQC Analysis Identifies Substantial Reductions in Roadside Pollutant Concentrations as a Result of COVID-19 Social and Travel Restrictions


AQC has updated its analysis of the impacts of COVID-19 social and travel restrictions on air quality, demonstrating a substantial reduction in NOx and NO2 concentrations, with concentrations at Marylebone Road reducing by as much as 30% for NOx and 20% for NO2.

There is widespread reporting of reductions in NOx and NO2 concentrations as a result of the COVID-19 pandemic. However, much of the published evidence for this has focused on comparing concentrations measured during two separate periods of time without consideration of confounding factors such as meteorology.

Air Quality Consultants Ltd has sought to isolate some of the variation caused by meteorological and seasonal factors from the measured ambient concentrations, and demonstrate whether there is an underlying trend of changing concentrations as a result of reducing emissions, in a report available here.

The analysis has considered measurements of nitrogen oxides (NOx), nitrogen dioxide (NO2), particulate matter (PM10 and PM2.5) and ozone (O3), taken across the UK, with a separate analysis looking at trends at two specific major urban roadside sites. 

The analysis has demonstrated that changes in concentrations cannot be identified from the raw measurement data alone, but that when the effects of meteorological and seasonal factors are removed, substantial reductions in NOx and NO2 concentrations become apparent. Concentrations at London’s Marylebone Road have reduced by around 30% for NOx and 20% for NO2 in March, most likely as a result of emissions reductions attributable to the social and travel restrictions.

Air Quality Consultants Ltd will continue to update this analysis over the coming weeks and months to better establish whether COVID-19 related social and travel restrictions continue to affect air quality in the UK, and whether NOx and NO2 concentrations reduce further.

© Air Quality Consultants 2021