Cancer incidence and mortality and proximity to TV towers.

OBJECTIVE

To determine whether there is an increased cancer incidence and mortality in populations exposed to radiofrequency radiations from TV towers.

DESIGN

An ecological study comparing cancer incidence and mortality, 1972-1990, in nine municipalities, three of which surround the TV towers and six of which are further away from the towers. (TV radiofrequency radiation decreases with the square of the distance from the source.) Cancer incidence and mortality data were obtained from the then Commonwealth Department of Human Services and Health. Data on frequency, power, and period of broadcasting for the three TV towers were obtained from the Commonwealth Department of Communications and the Arts. The calculated power density of the radiofrequency radiation in the exposed area ranged from 8.0 microW/cm2 near the towers to 0.2 microW/cm2 at a radius of 4km and 0.02 microW/cm2 at 12 km.

SETTING

Northern Sydney, where three TV towers have been broadcasting since 1956.

OUTCOME MEASURES

Rate ratios for leukaemia and brain tumour incidence and mortality, comparing the inner with the outer areas.

RESULTS

For all ages, the rate ratio for total leukaemia incidence was 1.24 (95% confidence interval [CI], 1.09-1.40). Among children, the rate ratio for leukaemia incidence was 1.58 (95% CI, 1.07-2.34) and for mortality it was 2.32 (95% CI, 1.35-4.01). The rate ratio for childhood lymphatic leukaemia (the most common type) was 1.55 (95% CI, 1.00-2.41) for incidence and 2.74 (95% CI, 1.42-5.27) for mortality. Brain cancer incidence and mortality were not increased.

CONCLUSION

We found an association between increased childhood leukaemia incidence and mortality and proximity to TV towers.