The impact of COVID-19 lockdowns on ethnic disparities in NO₂ exposure in England: A policy perspective on environmental injustice

Abstract

NO₂ pollution in England has steadily improved in recent decades; however, disparities in exposure among ethnic groups have persisted and, in some cases, worsened. While much of the literature provides observational evidence of environmental injustice in England, few studies have examined the temporal evolution of these disparities or the role of policy in shaping them. This study leverages the COVID-19 lockdowns as a natural experiment to examine changes in ethnic disparities in NO₂ exposure and quantify the differential impacts of lockdown policies. Using satellite-based NO₂ measurements aggregated at the local authority district level, we discovered shrinking ethnic gaps in NO₂ exposure from 2019 to 2021. Notably, while White populations consistently experienced lower NO₂ exposure (at least 5 µg/m³ lower) compared to Asian and Black groups, larger reductions in NO₂ were observed in districts with higher proportions of non-White residents (e.g., 7.29 µg/m³ reduction for Asian population in 2020). Regression results show the effect of lockdown policies on ethnic disparities in NO₂ reduction remained significant after controlling for mobility, income, urbanity and road density. This study highlights the equity implications of air quality policies and underscores the need for targeted interventions to alleviate the disproportionate NO₂ exposure burden on ethnic minorities in England.