An ecological study was conducted in Italy to investigate the mortality risk for leukemia among adults and the incidence of childhood leukemia in the population near the Vatican Radio station.
Vatican Radio station was installed in 1957 comprising 3 rotating and 28 fixed antennas with transmission powers ranging from 5 to 600 kW and different frequency ranges including 9 transmitters for short waves with frequencies of 4,005 - 21,850 kHz and 3 transmitters for medium waves with frequencies of 527 - 1,611 kHz.
The study area was divided in five bands with increasing distance from radio station.
|Group 1||distance to transmitter: 0 - 2 km|
|Group 2||distance to transmitter: 2 - 4 km|
|Group 3||distance to transmitter: 4 - 6 km|
|Group 4||distance to transmitter: 6 - 8 km|
|Group 5||distance to transmitter: 8 - 10 km|
including 9723 children
A total of 40 deaths of leukemia (21 men and 19 women) were observed within the distance of 10 km from the Radio Vatican station. No significant excess of mortality was found in the different bands with the exception of male adult mortality within 2 km to the radio station.
A total of 8 cases of childhood leukemia was observed in the 10 km area, all within 6 km from the radio station. The risk for childhood leukemia was higher than expected in the area up to 6 km (SIR 2.2, CI 1.0-1.4).
Although this study adds evidence of an excess of leukemia in a population living in the vicinity of high-power transmitters, no causal implications can be drawn.
The study has limitation due to the small number of cases and the lack of exposure data.