CANCER INCIDENCE NEAR RADIO AND TELEVISION TRANSMITTERS IN GREAT-BRITAIN .1. SUTTON COLDFIELD TRANSMITTER

A small area study of cancer incidence in 1974-1986 was carried out to investigate an unconfirmed report of a ''cluster'' of leukemias and l ymphomas near the Sutton Coldfield television (TV) and frequency modul ation (FM) radio transmitter in the West Midlands, England. The study used a national database of postcoded cancer registrations, and popula tion and socioeconomic data from the 1981 census. Selected cancers wer e hematopoietic and lymphatic, brain, skin, eye, male breast, female b reast, lung, colorectal, stomach, prostate, and bladder. Expected numb ers of cancers in small areas were calculated by indirect standardizat ion, with stratification for a small area socioeconomic index. The stu dy area was defined as a 10 km radius circle around the transmitter, w ithin which 10 bands of increasing distance from the transmitter were defined as a basis for testing for a decline in risk with distance, an d an inner area was arbitrarily defined for descriptive purposes as a 2 km radius circle. The risk of adult leukemia within 2 km was 1.83 (9 5% confidence interval 1.22-2.74), and there was a significant decline in risk with distance from the transmitter (p = 0.001). These finding s appeared to be consistent over the periods 1974-1980 and 1981-1986, and were probably largely independent of the initially reported cluste r, which appeared to concern mainly a later period. In the context of variability of leukemia risk across census wards in the West Midlands as a whole, the Sutton Coldfield findings were unusual. A significant decline in risk with distance was also found for skin cancer, possibly related to residual socioeconomic confounding, and for bladder cancer . Study of other radio and TV transmitters in Great Britain is require d to put the present results in wider context. No causal implications can be made from a single cluster investigation of this kind.