To study the potential responses of skin cells to millimeter wave exposure.
Four independent replicates per condition were used.
| Exposure | Parameters |
|---|---|
|
Exposure 1:
60.4 GHz
Modulation type:
CW
Exposure duration:
continuous for 1, 6, 24 h
|
|
| Frequency | 60.4 GHz |
|---|---|
| Type | |
| Charakteristic | |
| Exposure duration | continuous for 1, 6, 24 h |
| Modulation type | CW |
|---|
| Exposure source | |
|---|---|
| Distance between exposed object and exposure source | 27 cm |
| Setup | 8.5 cm x 12.7 cm culture plate (six wells) with 0.01 mm cell monolayers in each well placed in an incubator and irradiated from the bottom by a pyramidal horn antenna; horn antenna with an aperture of 22.2 mm x 16.7 mm and 17 dB gain |
| Sham exposure | A sham exposure was conducted. |
| Measurand | Value | Type | Method | Mass | Remarks |
|---|---|---|---|---|---|
| power | 425 mW | - | - | - | antenna output power |
| SAR | 39 W/kg | minimum | calculated | - | within the outer wells |
| SAR | 49.3 W/kg | maximum | calculated | - | within the inner wells |
| SAR | 42.4 W/kg | spatial average | calculated | - | averaged over all six wells |
| power density | 1.7 mW/cm² | - | - | - | in the outer wells |
| power density | 2.1 mW/cm² | - | - | - | in the inner wells |
| power density | 2.3 mW/cm² | peak value | - | - | - |
| power density | 1.8 mW/cm² | spatial average | - | - | averaged over all six wells |
No significant difference in gene expression was observed when gene expression values were subjected to a stringent statistical analysis (via t-test with a statistical correction). However, when a single t-test (less stringent) was applied, 130 transcripts were found to be potentially modulated after exposure. To further quantitatively analyze these preselected transcripts, real-time RT-PCR was performed on 24 genes with the best combination of high "fold change" and low P-value. Five of them were confirmed as differentially expressed after 6 h of exposure: CRIP2 (a zinc-binding protein involved in signaling, haematopoiesis, and cell proliferation), PLXND1 (a transmembrane receptor involved in development), PTX3 (a protein involved in innate immunity and inflammatory response), SERPINF1 (a secreted endopeptidase inhibitor that has anti-angiogenic and anti-proliferation functions), and TRPV2 (a calcium channel involved in sensory perception).
Compared to other microarray analyses studying the effect of pollutants or drug treatments, the number of responsive genes in the present study is extremely modest. Moreover, the gene expression modification is transient (mostly after 6 h of exposure) and with a limited amplitude (generally with a fold change close to 2). One can only wonder about the consequence on human health, of such subtle changes at cellular level. Thus, the authors conclude that millimeter waves (CW, 60.4 GHz, 1.8 mW/cm²) do not have any dramatic impact on primary cultures of human keratinocytes. However, they cannot exclude that millimeter waves could affect gene expression in vivo because skin is a complex tissue composed of different kinds of cells with various sensitivities.
This website uses cookies to provide you the best browsing experience. By continuing to use this website you accept our use of cookies.
