Effects of wind and electric fields on ²¹⁸ Po deposition from the atmosphere

ISSN： 1362-3095

Source： International Journal of Radiation Biology, Vol.75, Iss.12, 1999-12, pp. : 1533-1539

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

Purpose: To estimate, under atmospheric conditions, ²¹⁸ Po deposition on a sphere representing the human head and compare with the effects of the maximum electric field to be found under a transmission line. Method: The effect of the wind in the absence of electric fields was calculated using the Reynolds Analogy between heat and mass transfer. The effect of the electric field was shown to be large compared with that of turbulence. A 'capture radius' due to the field was then estimated and charged ²¹⁸ Po particles blown into this region were assumed to be captured. Results: The deposition ratio was proportional to gamma V ^0.4 E ^0.67, where gamma = charged fraction of ²¹⁸ Po, V = velocity and E ₀ = surface electric field. With the charged fraction ranging from 0.9% to 3.2%, a surface field on 280kVm ^-1 and a wind speed of 3ms ^-1 , the deposition ratio ranged from 3.4 to 9.3. The surface field is several orders of magnitude higher than the average personal exposures that have been measured in epidemiological studies and the effect does not appear to be of epidemiological significance. At low velocities, the predictions of this model are in agreement with the measurements of Henshaw et al. Conclusions: ²¹⁸ Po deposition by environmental AC fields cannot be advanced as an explanation for the reported associations between childhood leukaemia and electrical installations.