EMF Evidence Library
Research library/Brain & nervous system/RF-020
RF-020Original text reviewed

Blinded rat histology with significant findings at two of three exposure levels

Salford et al. · 2003 · Environmental Health Perspectives

The reported finding

After one 2-h exposure and approximately 50 days' recovery, the blinded semiquantitative dark-neuron score differed across four groups (Kruskal-Wallis p<0.002). Individual comparisons with sham: 0.002 W/kg p<0.2; 0.02 W/kg p=0.01; 0.2 W/kg p=0.03. The lowest group was not significant. Changes occurred particularly in cortex, hippocampus and basal ganglia.

Reading it carefully

Small mixed-sex, broad-age sample and subjective ordinal endpoint. Histology is a reported pathological endpoint, but permanent functional injury, apoptosis and human disease were not established. Direct replication did not confirm the outcome (Masuda 2009). Rat whole-body SAR cannot certify human local-SAR compliance.

Inside the study

Exposure conditions
GSM telephone fed into TEM cells, no voice modulation; nominal 915-MHz programme. Average whole-body SAR 0.002, 0.02, or 0.2 W/kg for 2 h; corresponding peak power densities 0.24, 2.4, 24 W/m². Brain SAR distribution simulated by FDTD, varying <6 dB. Room/cell air temperature controlled.
Design & controls
32 male and female Fischer 344 rats aged 12-26 weeks, 8/group including sham; awake, movable within chamber. Perfusion fixation; cresyl-violet staining and albumin immunohistochemistry. Neuropathologist blinded; dark-neuron score 0/1/2 (none/occasional, moderate, abundant).
Related research & shared cohorts
Same Lund programme as RF-027, RF-028, RF-029 and CTX-005. CTX-006 is a specific independent replication attempt, not a general safety review.
The protection question raised
Is the delayed dark-neuron signal reproducible and specific to injury rather than tissue handling or scoring? Its small sample, nonsignificant lowest dose and nonconfirming replication prevent a harmful human exposure threshold.
Source verification
Original three-page journal PDF read, including embedded correction; Scite supplied abstract only
Where to find the result
pp. 881-882 Materials and Methods; p.882 Results, Figure 3 and caption; p.883 Correction
Editorial notices
Embedded Correction on p.883 replaces Figure 1 from earlier immediately-sacrificed animals with present-study specimens (sham and 2 mW/kg). No separate notice DOI identified. Scite metadata did not surface this correction. No retraction/concern found in targeted search.
Funding
Swedish Council for Work Life Research grant (p.881).
Conflicts of interest
Authors declare no conflict of interest (p.881).

Reviews to read alongside

Related syntheses and proposals in the separate review collection. These are topical reading links, not additional independent experiments.

Original publication

Salford LG, Brun AE, Eberhardt JL, Malmgren L, Persson BRR. Nerve cell damage in mammalian brain after exposure to microwaves from GSM mobile phones. Environ Health Perspect. 2003;111(7):881-883. doi:10.1289/ehp.6039.

Plain-text record