Table 3

Monitored concentrations of NO₂ in Teesside (ppb)

Monitor. location (see table1)		Zone^3-150		Area		Type of monitoring
						National survey^3-151annual mean		Study survey 4 sample mean 1993		Continuous monitoring
						National survey^3-151annual mean				Monthly mean of hourly means 1993–4		Min–max highest hourly means 1993–4		Annual mean
						1986	1991			Monthly mean of hourly means 1993–4		Min–max highest hourly means 1993–4		1993	1994
	N/A	St Hilda's	22	24
	N/A	Billingham		26
	N/A	Stockton Centre	17	26
17	C	Ragworth Centre	17	20
1	A	Dormanstown			21
2	A	Grangetown			18	7–19	32–75	12	12
4	A	South Bank			19
6,8,10^3-152	B	East Middlesbrough			18	7–21	29–71	11	13
18	C	Blue Hall			20
19	C	Hardwick			18

↵3-150 Zone: A=near; B=intermediate; C=far.
↵3-151 National diffusion tube survey at six locations,26diffusion survey carried out specifically for this study at 22 sites, covering 2-weekly sampling on four occasions.
↵3-152 East Middlesbrough mean of locations in Brambles Farm, Netherfields, and Berwick Hill.