Table 1.

Data from Canada, Italy, England and mainland United States, with population in million and COVID-19 cases in thousand (up to 16th Oct, 2020). Covariate summary is shown by its 0.25 and 0.75 quantiles, with units $\mathrm{\mu }{\text{gm}}^{-3}$ for PM_2.5, ppb for NO${}_2$, % for unemployment rate and visible minorities, cases per 100,000 for lung cancer mortality. In addition, in Italy the index of material and social vulnerability was used in place of the unemployment.

	Canada	Italy	England	United States
Population	36.3	60.2	55.5	314.4
Areal units	93	107	149	3108
Total cases	194	373	560	7784
PM2.5	(5.37, 7.38)	(11.15, 16.12)	(7.59, 9.60)	(4.40, 6.90)
NO${}_2$	(2.52, 7.25)	(4.65, 9.69)	(8.00, 15.28)	(2.68, 4.58)
Unemployment	(6.70, 10.00)	(98.07, 99.74)	(1.40, 2.60)	(3.10, 4.80)
Visible minorities	(1.60, 6.70)	(4.18, 8.22)	(4.00, 25.50)	(4.47, 19.87)
Lung cancer	(62.65, 79.33)	(47.95, 61.15)	(85.10, 125.80)	(40.70, 57.50)