From Pandemic to Other Emergencies: A New Index Reflects Reduction of Air-Pollution Due to Changes in Mobility Pattern

During February-March of 2020 the majority of the world experienced an accelerating pandemic outbreak, driving the authorities to employ social distancing measures (lockdown) in order to slow the SARS-CoV2 spreading. While the pandemic restriction measures were implemented for health reasons, environmental implications became evident, as the social distancing restrictions escalated. A new quantitative index was developed as a ratio assigned to represent the severity of restriction measures on population mobility with respect to non-pandemic “business as usual” in the two greater-cities of Milan (Italy) and Tel-Aviv (Israel). Our index which we named as COVID19 Restrictions Index (C.R.I), was found to be following fairly well the trends and intensity of the apparent transportation-related NOx changes due to authorities’ measures. Although the C.R.I  was developed based on the pandemic “first wave”, a further evaluation of the C.R.I. conducted with data from a later moderated pandemic-measures period (late 2020) and with post-lockdowns data (2021), confirmed the consistency of the C.R.I. as an indicator for air-pollution changes related to public mobility indicators.

The new index is unique by its independence of population or monitoring databases. Therefore, it may be used to represent the potential impacts of restriction measures implemented upon populated areas, either for environmental assessments or planning, or for epidemiological models, air-pollution models or multi-factor analysis, in a broad scenario and not only for pandemic situation (an occurrence of a natural disaster, for example).

 

 

 

 

 

Haikin et al 2025 Environ. Res. Commun. https://doi.org/10.1088/2515-7620/ae0875