One of the major radiation-related scientific peer-reviewed journals, the Radiation Research, has just published a review article dealing with the role of calcium in mediation of non-thermal effects of EMF exposures: ‘Radiofrequency Fields and Calcium Movements Into and Out of Cells’ by Andrew Wood and Ken Karipidis.
Two of the references used by the authors comes from Martin L. Pall, well known to anti 5G-activists and presented in number of posts on BRHP.
Often conflict of interests (CoI) is an issue. Here, two curiosities can be seen… or not seen.
First, in the Acknowledgements section the authors specify that partial funding for this review came from the New Zealand Ministry of Health. It is a curious thing as both authors are Australians. Second curious thing is the lack of mention that while Karipidis works at ARPANSA, he is also a member of the Main Commission of ICNIRP, and this is a potential CoI to consider and to make it known. Why to leave it out? Should be no reason.
However, no matter whether ICNIRP link is mentioned or not, both authors are experts in the area of biological and health effects of RF-EMF and their review is good science.
In the abstract of the review article Wood and Karipidis state [emphasis added DL]:
The recent rollout of 5G telecommunications systems has spawned a renewed call to re-examine the possibility of so-called “non-thermal” harmful effects of radiofrequency (RF) radiation. The possibility of calcium being affected by low-level RF has been the subject of research for nearly 50 years and there have been recent suggestions that voltage-gated calcium channels (VGCCs) are “extraordinarily sensitive” to ambient RF fields. This article examines the feasibility of particularly modulated RF coupling to gating mechanisms in VGCCs and also reviews studies from the literature from the last 50 years for consistency of outcome. We conclude that the currents induced by fields at the ICNIRP guideline limits are many orders of magnitude below those needed to affect gating, and there would need to be a biological mechanism for detection and rectification of the extremely-low-frequency (ELF) modulations, which has not been demonstrated. Overall, experimental studies have not validated that RF affects Ca2+ transport into or out of cells.
The first part of the review presents detailed description of the calcium channels, including VGCC, in cells and their role in regulation of cell functions.
The second part of the review firstly presents theoretical considerations for:
- Coupling of RF to cells:
- The actual voltage drop across an individual membrane is thus of the order of 100 nV, given that the membrane thickness is approximately 10[–8] m. This is several orders of magnitude below the 25 mV (dc) mentioned previously for channel activation and this voltage is also alternating. With respect to alternating currents, the charge displacement required to activate the channel would only occur at frequencies up to a few kHz, which is several orders of magnitude below the frequencies considered here.
- Demodulation of extremely low frequency (ELF) modulation from RF carrier:
- While it is true that certain ion channels show rectification properties, this is in relationship to currents in the ELF range. It is unclear whether these properties would affect RF currents in the GHz range. There have been a number of attempts at demonstrating rectification properties at frequencies relevant to telecommunications, but these have failed.
The calculations are followed by a review of 30 research studies dealing with the calcium signalling listed in Table 1.
Then, the authors dealt with the question:
- Are external EMFs sufficient to activate VGCC?
- “Molecular dynamics simulations of ion channels in lipid bilayers have confirmed that there is no basis for the claim that Ca++ channels are in some way extremely sensitive to external fields. Recently reported simulations of Ca++ in particular (Feng et al.) have shown that reducing the potential by 40mV leads to the expected conformational changes allowing Ca++ permeation. E-fields across the actual membrane of the order of 120–650 MV/m (as 10 ns pulses) are required (Marracino et al.) to open channels (in this case, aquaporin channels, but Ca++ channels would behave similarly).”
- Are VGCC unique?
- No… “claims that VGCCs in some way represent an amplification of forces by several orders of magnitude (Pall) appear not to be borne out by evidence.”
The authors concluded, among others:
- “…Despite nearly 50 years of research into possible effects of RF on cellular calcium levels, results continue to be mixed and a mechanism for action, if the effect is real, elusive. Those experiments reporting changes in cell Ca++ are roughly equally divided between those that can be interpreted as a loss to cytoplasmic Ca++ and those as an increase. The greatest proportion (40%) report no changes at all. Furthermore, the majority of the studies with higher quality score did not report an effect. Those experiments targeting VGCC by direct measurement of cell Ca++ currents do not show significant RF effects. Since GHz
RF fields alternate too quickly for there to be alterations in ion flow, it is unclear how dc gating currents could be affected, with no evidence for demodulation occurring in biological membranes. The change in field across the membrane required to transition a gate from the ‘‘closed’’ to ‘‘open’’ condition is of the order of several MV/m, which is considerably higher than the modest fields induced across membranes by external EMF at the respective ELF or RF reference levels [20 kV/m and 87 V/m, respectively (3, 71)]. There appears to be no basis for the claim that VGCCs are extraordinarily sensitive to environmental RF-EMF…”
Summa summarum, Wood and Karipidis indicate that the current knowledge, and calculations presented by them, do not support the notion that VGCC would be involved in RF-exposure-induced calcium signalling and the potentially related non-thermal effects.
Finally, Wood and Karipidis stress the need for better quality in the future studies:
- “…As methods for estimating subcellular [Ca++], pH and temperature improve, it may be prudent to revisit the ‘‘calcium effect’’, particularly patch-clamping experiments targeting VGCCs, to endeavor to uncover reasons for disparity in outcomes. Future experiments should give even greater attention to aspects of improving ‘‘quality’’, specifically, the use of blinding, positive controls and dosimetry estimations, including modeling. It is extremely important to eliminate artefact, in particular, the possibility of localized heating…”
Also, I doubt it will happen, but Martin L. Pall is welcome to respond in Guest Blog to opinions of Lai, Vriens, Wood and Karipidis… (I e-mailed Martin L. Pall and asked if he has any interest to respond with a guest blog post)