Effects of continuous and pulsed 2450‐MHz radiation on spontaneous lymphoblastoid transformation of human lymphocytes in vitro

Abstract

Normal human lymphocytes were isolated from the peripheral blood of healthy donors. One-ml samples containing (10(6)) cells in chromosome medium 1A were exposed for 5 days to conventional heating or to continuous wave (CW) or pulsed wave (PW) 2450-MHz radiation at non-heating (37 degrees C) and various heating levels (temperature increases of 0.5, 1.0, 1.5, and 2 degrees C). The pulsed exposures involved 1-microsecond pulses at pulse repetition frequencies from 100 to 1,000 pulses per second at the same average SAR levels as the CW exposures. Actual average SARs ranged to 12.3 W/kg. Following termination of the incubation period, spontaneous lymphoblastoid transformation was determined with an image analysis system. The results were compared among each of the experimental conditions and with sham-exposed cultures. At non-heating levels, CW exposure did not affect transformation. At heating levels both conventional and CW heating enhanced transformation to the same extent and correlate with the increases in incubation temperature. PW exposure enhanced transformation at non-heating levels. This finding is significant (P less than .002). At heating levels PW exposure enhanced transformation to a greater extent than did conventional or CW heating. This finding is significant at the .02 level. We conclude that PW 2450-MHz radiation acts differently on the process of lymphoblastoid transformation in vitro compared with CW 2450-MHz radiation at the same average SARs.

Basis for optimization of in vitro exposure apparatus for health hazard evaluations of mobile communications

“…Waveguide systems have also been widely used in the past [e.g., Czerska et al, 1992;Joyner et al, 1989]. The¯asks can be oriented in E, k or H polarization.…”

A new in vitro exposure device for the mobile frequency of 900 MHz

“…The SAR level obtained with the wire patch cell reveals its main advantage: in comparison to TEM cells, the system based on wire patch antenna induces SAR levels about 20 times higher [Burkhardt et al,1996]. Another exposure device, the waveguide, has an excellent ef®ciency, but in comparison to the wire patch cell, it is a large device and requires a rather complex loading construction [Joyner et al, 1989;Czerska et al, 1992]. Furthermore, in the RF chamber [Meltz et al, 1988;Gos et al, 1997], which has also a high ef®ciency, the homogeneous absorption can only be achieved with a complex and expensive construction.…”

Services to Operate and Maintain the Microwave Research Facility at Brooks Air Force Base, San Antonio, Texas

“…On the other hand, Czerska et al [1992] provided convincing evidence of a profound stimulatory effect of pulsed 2.45 GHz on the sponntaneous lymphoblastoid transformation of cultured human lymphocytes (Fig. 4).…”

“…The mitotic index of human lymphocytes in culture was used for identifying the presence of spontaneous Lymphoblastoid transformation. Pulse characteristics were 1 jus pulse duration, 1,200 [Czerska et al 1992] as shown in Fig. 4.…”