Table 3.

Correlations of BB symptom scores with average monthly environment variables (UK-wide, March–Sept incl.).

Environment measure (UK)	BB symptom (urban)	Correlation	p (2-tailed)
${\text{SO}}_2$ mean	Eyes	−0.7163	$\le$.001
${\text{NO}}_x$ mean	Eyes	−0.6446	$\le$.001
${\text{SO}}_2$ mean	Nose	−0.6248	$\le$.001
${\text{NO}}_2$ mean	Eyes	−0.6009	$\le$.001
${\text{NO}}_x$ max	Eyes	−0.6005	$\le$.001
${\text{NO}}_x$ mean	Breathing	−0.596	$\le$.001
${\text{NO}}_2$ max	Eyes	−0.573	$\le$.001
${\text{NO}}_x$ mean	Nose	−0.5728	$\le$.001
${\text{NO}}_2$ mean	Breathing	−0.5658	$\le$.001
${\text{SO}}_2$ mean	Breathing	−0.5627	$\le$.001
${\text{NO}}_x$ mean	Max_score	−0.56	$\le$.001
${\text{NO}}_x$ max	Nose	-0.5468	$\le$.001
${\text{NO}}_x$ max	Max_score	-0.5428	0.0011
${\text{NO}}_x$ max	Taken_medication	-0.5326	0.0014
${\text{NO}}_2$ max	Breathing	−0.5116	0.0023
${\text{NO}}_x$ max	Breathing	−0.5024	0.0029
${\text{NO}}_2$ mean	Max_score	−0.4904	0.0038
${\text{NO}}_2$ mean	Nose	−0.4902	0.0038
${\text{NO}}_x$ mean	Taken_medication	−0.4882	0.0039
${\text{SO}}_2$ max	Eyes	−0.484	0.0043
${\text{NO}}_2$ max	Max_score	−0.4693	0.0059
${\text{NO}}_2$ max	Nose	−0.4652	0.0064
${\text{SO}}_2$ mean	Max_score	−0.4538	0.008
Grass (Poaceae)	Max_score	0.4379	0.0108
${\text{O}}_3$ max	Taken_medication	0.4268	0.0133
${\text{O}}_3$ max	Nose	0.395	0.0229
Rel. hum. mean	Taken_medication	−0.384	0.0274
${\text{SO}}_2$ max	Breathing	−0.3816	0.0285
Rel. hum. mean	Nose	−0.3792	0.0295
Grass (Poaceae)	Eyes	0.3751	0.0315
${\text{O}}_3$ mean	Taken_medication	0.3729	0.0326
Temperature max	Breathing	0.3629	0.0379
${\text{O}}_3$ mean	Nose	0.362	0.0385
${\text{NO}}_2$ mean	Taken_medication	−0.3571	0.0413
Hazel (Corylus spp.)	Breathing	−0.3562	0.0419
${\text{NO}}_2$ max	Taken_medication	−0.3558	0.0422
Rel. hum. mean	Max_score	−0.3548	0.0427

Environment measure (UK)	BB symptom (rural)	Correlation	p (2-tailed)
Grass (Poaceae)	Eyes	0.3852	0.0269
Grass (Poaceae)	Nose	0.3834	0.0276
${\text{SO}}_2$ mean	Taken_medication	0.3663	0.036
Grass (Poaceae)	Max_score	0.3497	0.046

Only significant correlations (indicated by p values $\le$ 0.05) are included here.