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BackgroundAir pollution is associated with poor health. Yet, more research is needed to reveal the association of long-term exposure to outdoor air pollution with less studied health outcomes like hospital admissions and general-practitioner (GP) visits and whether this association is stronger for ethnic minorities compared to the rest of population. This study investigates the association between air pollution and all-cause GP visits and hospital admissions by ethnicity in the United-Kingdom (UK).MethodsWe used individual-level longitudinal data from the “UK Household Longitudinal Study” including 46,442 adult individuals who provided 140,466 responses across five years (2015–2019). This data was linked to yearly concentrations of NO2, SO2, and particulate-matter (PM10, PM2.5) outdoor pollution using the Lower Super Output Area (LSOA) of residence for each individual. Multilevel mixed-effects ordered logistic models were used to assess the association between air pollution and all-cause GP visits and hospital admissions.ResultsWe found higher odds of hospital admissions per 1 μg/m3 increase in annual concentrations of NO2 (OR = 1.008; 95%CI = 1.004–1.012), SO2 (OR = 1.048; 95%CI = 1.014–1.083), PM10 (OR = 1.011; 95%CI = 1.003–1.018), and PM2.5 (OR = 1.018; 95%CI = 1.007–1.029) pollutants. Higher odds of GP visits were also observed with increased exposure to NO2 (OR = 1.010; 95%CI = 1.006–1.014) and SO2 (OR = 1.114; 95%CI = 1.077–1.152) pollutants. The observed associations did not differ across ethnic groups, but by country of birth, they were more pronounced in individuals born outside UK than those born in UK.ConclusionThis study supports an association between higher exposure to outdoor air pollution and increased all-cause hospital admissions and GP visits. Further longitudinal studies with longer follow-up time periods may be able to reveal more definite conclusions on the influence of ethnicity on the association between long-term outdoor air pollution and both hospital admissions and GP visits.