Table 1.

Differences between the average concentration level of the sub-period 2014–2018 and the treatment period 2019. Differences are expressed in $\mathsf{\mu }$g/m${}^3$.

Station Name	Nitrogen Oxides		Nitrogen Dioxide
	${\mathit{d}}_{\mathit{AVG}}$	${\mathit{d}}_{\mathit{MED}}$	${\mathit{d}}_{\mathit{AVG}}$	${\mathit{d}}_{\mathit{MED}}$
Milano city stations
Città Studi	0.94	−0.43	−2.63	−4.26
Liguria	−25.59	−26.91	−19.49	−20.71
Marche	−17.29	−22.00	−11.53	−13.37
Senato	−14.99	−13.84	−10.46	−9.73
Verziere	−2.66	−5.00	−4.35	−5.78
Other urban centres in Lombardy
Bergamo	−11.56	−8.90	−5.11	−4.07
Brescia	−4.61	−6.39	−3.46	−4.12
Cremona	3.47	1.10	1.53	0.85
Lodi	−5.99	−7.62	-1.85	−2.57
Pavia	−14.75	−17.77	−7.75	−9.28
Saronno	−7.96	−7.84	−8.66	−8.87
Treviglio	0.06	−3.71	2.25	0.39