Association between annual mean levels of air pollutants and COVID-19 incidence rate, and estimated number of additional COVID-19 cases due to air pollution, in single-pollutant models
| Air pollutant | Model 1 | Model 2 | ||||
| RR | 95% CI | RR | 95% CI | Cases* | 95% CI | |
| PM2.5 | 1.051 | 1.027 to 1.076 | 1.051 | 1.027 to 1.075 | 294.1 | 152.7 to 435.5 |
| PM10 | 1.040 | 1.021 to 1.060 | 1.040 | 1.020 to 1.060 | 230.9 | 115.6 to 346.1 |
| NO2 | 1.020 | 1.009 to 1.030 | 1.020 | 1.009 to 1.030 | 113.1 | 51.7 to 174.5 |
| NO | 1.041 | 1.014 to 1.068 | 1.040 | 1.013 to 1.068 | 235.5 | 70.6 to 400.4 |
| O3 | 0.980 | 0.970 to 0.990 | 0.980 | 0.970 to 0.990 | −115.0 | −174.0 to −57.0 |
Rate ratios (RRs) per 1 µg/m3 increase in the annual average exposure to each pollutant estimated from Poisson regression models.
Model 1: single pollutants, adjusting for age, sex and living in a residential care home.
Model 2: Model 1 + positive history of stroke, treatment for diabetes, antihypertensive treatment and treatment for obstructive airway diseases.
*Number of cases per 100 000 person-years due to 1 µg/m3 increase in the pollutant above its mean value, estimated at the mean values of the confounders.