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.　©　2025