Fig. 4
Outcome parameters and NO2-levels and PM2.5-levels over time. A) Incidence and mortality and NO2-levels and PM2.5-levels over time in March – May 2020. Pollution variables for a given date are given as average of the previous 48 h. The dashed colored lines are WHO-recommended thresholds annual average levels of NO2 and PM2.5. The pink line indicates the period for which data is available in the DIVI-register. B) Patient-days on ICU and on mechanical ventilation and NO2-levels and PM2.5-levels over time in April – May 2020. The dashed colored lines are WHO-recommended thresholds for annual average levels of NO2 and PM2.5