Table 3.

Descriptive statistics for environmental pollutants, meteorological parameters and vehicular mobility. Results are summarized for the total, the two studied periods separately (1st Wave and summer) with significant difference reported by p-value of Wilcoxon or t-paired test, and geographic position (North and Centre-South) with significant differences reported by p-value of Mann-Whitney or t-test (depending on data distribution).

Potential determinants	n	Arithmetic Mean ± S.D.	Median [IQR]	Min-Max	p-value 1stW vs S	p-value N vs C–S
Environmental pollutants
PM2.5 (μg/m3)
Total	96	12.1 ± 5.3	11.9 [6.3]	3.2–32.9	<0.001	0.053
1st Wave	48	14.0 ± 6.1	13.1 [9.0]	3.2–32.9		0.001
Summer	48	10.1 ± 3.6	9.2 [5.2]	3.4–21.0		0.544
North	36	13.4 ± 5.3	12.9 [9.5]	4.9–25.7
Centre-South	60	11.3 ± 5.3	11.0 [5.3]	3.2–32.9
PM2.5-10(μg/m3)
Total	110	7.7 ± 4.2	7.1 [4.6]	1.3–27.3	0.378	0.559
1st Wave	56	7.6 ± 4.8	6.8 [5.0]	1.3–27.3		0.268
Summer	54	7.8 ± 3.5	7.4 [4.1]	1.4–16.1		0.716
North	43	7.8 ± 3.7	6.9 [5.1]	1.3–20.5
Centre-South	67	7.7 ± 4.5	7.1 [3.4]	1.4–27.3
NO2(μg/m3)
Total	112	24.5 ± 13.2	21.8 [17.8]	3.0–60.9	0.004	0.819
1st Wave	56	28.2 ± 14.3	27.3 [20.6]	6.3–60.9		0.597
Summer	56	20.7 ± 11.0	17.4 [13.9]	3.0–55.4		0.330
North	44	23.6 ± 11.2	21.9 [14.7]	7.7–57.0
Centre-South	68	25.1 ± 14.5	21.2 [20.0]	3.0–60.9
O3(μg/m3)
Total	108	75.1 ± 24.7	79.9 [33.2]	24.9–128.1	<0.001	0.030
1st Wave	55	65.2 ± 22.7	71.7 [45.1]	24.9–104.3		0.002
Summer	53	85.4 ± 22.4	89.0 [30.2]	29.6–128.1		0.563
North	42	67.7 ± 26.5	72.7 [49.8]	24.9–112.9
Centre-South	66	79.8 ± 22.4	83.5 [29.3]	29.6–128.1
SO2(μg/m3)
Total	84	3.2 ± 2.5	2.8 [2.7]	0.3–16.1	0.549	0.548
1st Wave	43	3.5 ± 3.0	3.0 [3.3]	0.7–16.1		0.559
Summer	41	2.9 ± 2.0	2.7 [2.4]	0.3–8.6		0.831
North	33	3.5 ± 3.0	3.0 [2.9]	0.9–16.1
Centre-South	51	3.0 ± 2.2	2.7 [2.7]	0.3–10.4
Meteorological parameters
T (°C)
Total	114	17.2 ± 7.8	16.1 [14.9]	2.6–29.4	<0.001	0.014
1st Wave	57	9.9 ± 2.4	10.3 [2.9]	2.6–14.0		<0.001
Summer	57	24.6 ± 2.9	25.1 [4.4]	18.2–29.4		0.055
North	46	15.8 ± 8.3	15.0 [15.8]	2.6–28.7
Centre-South	68	18.2 ± 7.4	16.1 [14.5]	6.0–29.4
rH (%)
Total	114	65.1 ± 9.8	65.1 [13.9]	41.2–90.9	0.267	0.021
1st Wave	57	66.6 ± 9.4	65.0 [14.0]	46.0–90.9		0.276
Summer	57	63.7 ± 10.1	65.1 [14.6]	41.2–81.5		0.018
North	46	68.0 ± 9.8	69.4 [15.9]	49.4–90.9
Centre-South	68	63.2 ± 9.4	64.0 [10.8]	41.2–80.9
WS (m/s)
Total	114	2.2 ± 1.1	2.1 [1.3]	0.4–5.5	0.132	<0.001
1st Wave	57	2.1 ± 1.1	1.8 [1.4]	0.4–5.5		0.055
Summer	57	2.4 ± 1.1	2.1 [1.5]	0.5–5.2		<0.001
North	46	1.7 ± 0.8	1.7 [1.0]	0.4–4.2
Centre-South	68	2.6 ± 1.1	2.5 [1.4]	0.9–5.5
IR (MJ/m2)
Total	114	14.6 ± 41.0	14.7 [61.0]	39.7–21.8	<0.001	<0.001
1st Wave	57	11.5 ± 29.1	11.8 [38.0]	39.7–17.5		<0.001
Summer	57	17.7 ± 25.1	17.7 [37.5]	11.6–21.8		<0.001
North	46	12.6 ± 41.2	13.0 [73.1]	39.7–20.1
Centre-South	68	16.0 ± 34.8	16.5 [57.2]	98.3–21.8
Vehicular mobility vs baseline (%)
Total	114	−2.9 ± 41	−7.2 [42.1]	−75.0–141.0	<0.001	0.054
1st Wave	57	−30.6 ± 21.2	−23.7 [38.4]	−75.0-(-1.0)		0.929
Summer	57	24.8 ± 37.0	17.6 [32.5]	−51.6–141.0		<0.001
North	46	−11.6 ± 34.3	−12.3 [29.0]	−75.0–141.0
Centre-South	68	3.0 ± 44.2	−3.4 [54.1]	−68.1–128.7