Table 2.

Spearman correlations between ward-level reductions in NO_x and ward-level socio-demographic variables

Variable	Description	Δ Inc	IMD	Δ 65 years +	% NW	% Bl	% As	% Ch
Δ NOx	Reductions in average NOx from 2001–2002 to 2003–2004 in μg/m3	−0.21*	0.27*	0.13*	0.03	0.14*	−0.10	−0.02
Δ Inc	Change in proportion of residents living in income deprivation between 2001 and 2005		−0.21*	−0.16*	−0.34*	−0.21*	−0.42*	0.23*
IMD	Index of Multiple Deprivation in 2001 (higher values for more deprived wards)			0.26*	0.61*	0.78*	0.18*	0.13*
Δ 65 years +	Change in population aged 65 years or older between 2001–2002 and 2003–2004				0.02	0.16*	−0.07	−0.02
% NW	% Non-white residents					0.79*	0.73*	0.30*
% Bl	% Black residents						0.29*	0.18*
% As	% Asian residents							0.25*
% Ch	% Chinese residents

^*p<0.01.