Yet another study claiming DNA damage but is it any progress or yet another unconvincing observation

Recently, research study published by the research team led by Igor Belyaev has attracted somewhat enthusiastic attention of anti-5G activists.

The article in question is:

Effects of different mobile phone UMTS signals on DNA, apoptosis and oxidative stress in human lymphocytes. By Gulati S, Kosik P, Durdik M, Skorvaga M, Jakl L, Markova E, Belyaev I., published in Environ Pollut. 2020, doi: 10.1016/j.envpol.2020.115632. Epub 2020 Sep 11. PMID: 33254645

Abstract:

“Different scientific reports suggested link between exposure to radiofrequency radiation (RF) from mobile communications and induction of reactive oxygen species (ROS) and DNA damage while other studies have not found such a link. However, the available studies are not directly comparable because they were performed at different parameters of exposure, including carrier frequency of RF signal, which was shown to be a critical for appearance of the RF effects. For the first time, we comparatively analyzed genotoxic effects of UMTS signals at different frequency channels used by 3G mobile phones (1923, 1947.47, and 1977 MHz). Genotoxicity was examined in human lymphocytes exposed to RF for 1 h and 3 h using complimentary endpoints such as induction of ROS by imaging flow cytometry, DNA damage by alkaline comet assay, mutations in TP53 gene by RSM assay, preleukemic fusion genes (PFG) by RT-qPCR, and apoptosis by flow cytometry. No effects of RF exposure on ROS, apoptosis, PFG, and mutations in TP53 gene were revealed regardless the UMTS frequency while inhibition of a bulk RNA expression was found. On the other hand, we found relatively small but statistically significant induction of DNA damage in dependence on UMTS frequency channel with maximal effect at 1977.0 MHz. Our data support a notion that each specific signal used in mobile communication should be tested in specially designed experiments to rule out that prolonged exposure to RF from mobile communication would induce genotoxic effects and affect the health of human population.”

The authors have examined effect of three frequencies of RF on several biological end points in human lymphocytes obtained from the umbilical cord blood.

The authors pointed towards two, in their opinion, significant findings:

  1. Most of the examined end points were not affected by 1h or 3h RF exposures
  2. RF exposures caused “small but statistically significant induction of DNA damage” by one of the tested RF frequencies

Using these observations the authors concluded that:

“…Our data support a notion that each specific signal used in mobile communication should be tested in specially designed experiments to rule out that prolonged exposure to RF from mobile communication would induce genotoxic effects and affect the health of human population.…”

Following the “noise” on social media it was possible to notice somewhat excited reception of the results of this study. However, is the excitement justified or should we wait for more definite data?

First, a bucket of cold water.

The authors examined several biological end points:

  • ROS by imaging flow cytometry,
  • mutations in TP53 gene by RSM assay,
  • preleukemic fusion genes (PFG) by RT-qPCR, and
  • apoptosis by flow cytometry

and neither of them responded to RF exposures:

“…No effects of RF exposure on ROS, apoptosis, PFG, and mutations in TP53 gene were revealed regardless the UMTS frequency…”

However, the authors observed that RF exposure caused damage to DNA, as determined by the comet assay and it was the sole basis of the overall conclusion of the study.

A closer look at the comet assay results shows that the authors likely overstated the result of their study and that the conclusion might be, for now, misleading and requiring better confirmation.

Here is the description of the DNA results in its entirety so that the readers, if not trusting my opinion, may judge it for themselves:

3.1. DNA damage

UCB cells from three different probands were exposed to UMTS RF at different frequencies (1923, 1947.47, or 1977 MHz) for 1 h and 3 h. Upon RF exposure, DNA damage was analyzed by alkaline comet assay. The representative photomicrographs of cells with damaged DNA are shown in Fig. 1A & B. Blood lymphocytes are known to be very sensitive to apoptosis, for instance induced by regular freeze and thaw process. Apoptotic cells were differentiated from viable cells according to the appropriate guidelines (Fig. 1C) and were not analyzed for DNA damage by the comet assay. TBHP treated cells [… it was positive control…] have shown statistically significant increase in the TM compared to the untreated cells (ANOVA, p < 0.001). The TMs measured in cells after RF exposure are shown in Table 1. Analysis of data by multifactorial ANOVA has shown statistically significant dependence of the tail moment on RF exposure (p = 0.04). However, no dependence on exposure duration was revealed providing possibility for pooling the data for 1 and 3 h. The RF effect was also observed as a higher tail moment in the samples exposed at the 1977 MHz frequency if the data from 1-h and 3-h exposures were pooled (p = 0.04). Further analysis of the 1977 MHz effects split according to the duration of exposure did not show higher TM in the exposed samples. Analysis of pooled or split data at other frequencies, 1923 or 1947.47 GHz, did not show statistically significant effect of RF exposure on DNA damage. Summarizing the results, we observed relatively low but statistically significant effect of RF exposure on DNA damage in lymphocytes indicating dependence of this effect on the frequency of the UMTS signal.

To me, the results appear to be not entirely convincing.

Table 1 shows that exposures for 1h and 3h, for three different RF frequencies, as compared with sham, were not statistically significant.Authors state the following, but not show how they got the result, except to referring to multifactorial ANOVA:

“…Analysis of data by multifactorial ANOVA has shown statistically significant dependence of the tail moment on RF exposure (p = 0.04)…”

The authors claim that the pooling data from 1h and 3h suggested statistical significance for a single RF frequency but it might be disputable whether 1h and 3h samples can be analyzed together, only because their comparison does not show statistical difference in DNA damage. However, these samples were processed differently since they were exposed for different periods of time.

In the end, out of the quite thorough examination of several biological end points, only a single one, has shown a small effect of RF exposure that was not exposure-time dependent.

I think that the final conclusion is very much overstated.

“…we observed relatively low but statistically significant effect of RF exposure on DNA damage in lymphocytes indicating dependence of this effect on the frequency of the UMTS signal.”

 This result might be considered as an indicator of something as well as just a statistical anomaly.

To accept the claim of the effect, of a single frequency on DNA in time-independent manner, the authors should have confirmed it with at least one another technique, detecting DNA-damage. As for now the observation is solely a weak indication of a possibility of an effect, but far from any convincing evidence or proof.

Finally, the fate of the damaged DNA is completely unknown and any claims of danger to health are premature. We do not know whether the damaged DNA would be repaired or whether the cells with damaged DNA would self-destruct by apoptosis or whether the damaged DNA would be passed on to next generation of cells. As long as we do not know this, we do not know whether the DNA damage is harmful or not. We also should remember that DNA damage is so far shown in some animal studies and in vitro studies but we do not know if the DNA damage occurs in living people and whether this damage is of such magnitude that it could affect human health.

We do not know a lot…

3 thoughts on “Yet another study claiming DNA damage but is it any progress or yet another unconvincing observation

  1. Pingback: Efter løgneskandalen: Kan mobilstråling så ødelægge vores gener? Videnskaben er kompliceret – Tabt Tråd

  2. Wilhelm, absolutely, it is correct and timely question because it asks how good is the study that in conclusions claims much more than data permits. Dariusz

  3. Hi Darius, I am positively surprized that you call Gulati et al. (2020) “just another paper describing RF-EMF exposure associated DNA-damage and ask “Where is the progress?” I agree, DNA damage seen only once and never again could be a statistical anomaly, but with the number of reports since Henry Lai’s work in 1995, the question “Where is the progress” is more than justified.

    In 2005 and 2008, Alexander Lerchl accused the REFLEX – research team in Vienna of data fabbrication and scientific fraud. They had described RF-EMF exposure associated DNA damage in human cells. Today we can say that these accusation were launched by a lie-story-distributor, nothing more, so let’s go back to science again and investigate possible mechanisms etc.

    These accusations did not destroy the scientists knowledge on “RF-EMF eposure related DNA damage”. Appearantly, it destroyed the stakeholders dedication to progress the science with research. Where are the big systematic research programmes one would need to answer your question: “Where is the progress?”
    In short: Do you consider it fair, – in times of very poor (or no) funding – to load your “big question” over a single publication investigating DNA damage and possible related endpoints?

    best Wilhelm Mosgoeller

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