Table 1.

Distance of address at birth from nearest National Grid line for cases and controls in each diagnostic group, and estimated relative (RR)

	Leukaemia			CNS/brain tumours			Other diagnoses
Distance to line (metres)	Cases	Controls	RR	Cases	Controls	RR	Cases	Controls	RR
0-49	5	3	1.67	3	7	0.44	7	6	1.17
50-99	19	11	1.79	4	6	0.69	15	16	0.91
100-199	40	25	1.64	26	32	0.82	37	45	0.81
200-299	44	39	1.16	38	28	1.35	66	76	0.87
300-399	61	54	1.15	35	30	1.19	79	65	1.21
400-499	78	65	1.23	40	42	0.96	80	97	0.82
500-599	75	56	1.36	54	41	1.33	86	85	1.01
≥600 (reference group)	9378	9447	1.00	6405	6419	1.00	12 406	12 386	1.00
Total	9700	9700		6605	6605		12 776	12 776

CNS=central nervous system.