Electromagnetic fields and DNA damage

Abstract

A major concern of the adverse effects of exposure to non-ionizing electromagnetic field (EMF) is cancer induction. Since the majority of cancers are initiated by damage to a cell's genome, studies have been carried out to investigate the effects of electromagnetic fields on DNA and chromosomal structure. Additionally, DNA damage can lead to changes in cellular functions and cell death. Single cell gel electrophoresis, also known as the ‘comet assay’, has been widely used in EMF research to determine DNA damage, reflected as single-strand breaks, double-strand breaks, and crosslinks. Studies have also been carried out to investigate chromosomal conformational changes and micronucleus formation in cells after exposure to EMF. This review describes the comet assay and its utility to qualitatively and quantitatively assess DNA damage, reviews studies that have investigated DNA strand breaks and other changes in DNA structure, and then discusses important lessons learned from our work in this area. The comet assay for measurement of DNA strand breaks DNA is continuously damaged by endogenous and exogenous factors and then repaired by DNA repair enzymes. Any imbalance in damage and repair and mistakes in repair result in accumulation of DNA damage. Eventually, this will lead to cell death, aging, or cancer. There are several types of DNA lesions. The common ones that can be detected easily are DNA strand breaks and DNA crosslinks. Strand breaks in DNA are produced by endogenous factors, such as free radicals generated by mitochondrial Radiofrequency radiation (RFR) and DNA damage In a series of publications, Lai and Singh [16], [17], [18], [19] reported increases in single- and double-strand DNA breaks, as measured by the comet assay, in brain cells of rats exposed for 2 h to a 2450-MHz RFR at whole body specific absorption rate (SAR) between 0.6 and 1.2 W/kg. The effects were blocked by antioxidants, which suggested involvement of free radicals. At the same time, Sarkar et al. [20] exposed mice to 2450-MHz microwaves at a power density of 1 mW/cm2 for 2 h/day over a period Extremely low frequency electromagnetic fields (ELF EMF) and DNA damage To complete the picture, a few words on the effects of ELF EMF are required, since cell phones also emit these fields and they are another common form of non-ionizing EMF in our environment. Quite a number of studies have indicated that exposure to ELF EMF could lead to DNA damage [54], [55], [56], [57], [58], [59], [60], [61], [62], [63], [64], [65], [66], [67], [68], [69]. In addition, two studies [70], [71] have reported effects of ELF fields on DNA repair mechanisms. Free radicals and Some considerations on the effects of EMF on DNA From this brief literature survey, no consistent pattern of RFR exposure inducing changes in or damage to DNA in cells and organisms emerges. However, one can conclude that under certain conditions of exposure, RFR is genotoxic. Data available are mainly applicable only to radiation exposure that would be typical during cell phone use. Other than the study of Phillips et al. [21], there is no indication that RFR at levels that one can experience in the vicinity of base stations and Lessons learned Whether or not EMF causes biological effects, let alone effects that are detrimental to human health and development, is a contentious issue. The literature in this area abounds with apparently contradictory studies, and as presented in this review, the literature specific to the effects of RFR exposure on DNA damage and repair in various biological systems is no exception. As a consequence of this controversy, there are several key issues that must be addressed—contrary data, weight of Summary Exposure of laboratory animals in vivo and of cultured cells in vitro to various radiofrequency signals has produced changes in DNA damage in some investigations and not in others. That many of the studies on both sides of this issue have been done well is encouraging from a scientific perspective. RFR exposure does indeed appear to affect DNA damage and repair, and the total body of available data contains clues as to conditions producing effects and methodologies to detect them. This view is

AI evidence extraction

Main findings

Studies show mixed results regarding DNA damage from radiofrequency radiation (RFR) and extremely low frequency (ELF) electromagnetic fields. Some investigations report DNA strand breaks and repair effects under certain exposure conditions, while others do not. Overall, RFR exposure typical of cell phone use can be genotoxic under specific conditions, but evidence is inconsistent.

Outcomes measured

• DNA strand breaks
• DNA crosslinks
• chromosomal conformational changes
• micronucleus formation
• DNA repair mechanisms

Limitations

• Contradictory and inconsistent study results
• Variability in exposure conditions and methodologies
• Limited applicability to typical environmental exposures
• Complexity in measuring DNA damage and repair

Suggested hubs

• who-icnirp (0.8)
  Discussion of exposure levels relevant to cell phone use and base stations, relevant to international guidelines.

{
    "study_type": "review",
    "exposure": {
        "band": "RF and ELF",
        "source": "cell phones, base stations, microwaves",
        "frequency_mhz": 2450,
        "sar_wkg": 0.59999999999999997779553950749686919152736663818359375,
        "duration": "various, including 2 hours and repeated exposures"
    },
    "population": "laboratory animals (rats, mice) and cultured cells",
    "sample_size": null,
    "outcomes": [
        "DNA strand breaks",
        "DNA crosslinks",
        "chromosomal conformational changes",
        "micronucleus formation",
        "DNA repair mechanisms"
    ],
    "main_findings": "Studies show mixed results regarding DNA damage from radiofrequency radiation (RFR) and extremely low frequency (ELF) electromagnetic fields. Some investigations report DNA strand breaks and repair effects under certain exposure conditions, while others do not. Overall, RFR exposure typical of cell phone use can be genotoxic under specific conditions, but evidence is inconsistent.",
    "effect_direction": "mixed",
    "limitations": [
        "Contradictory and inconsistent study results",
        "Variability in exposure conditions and methodologies",
        "Limited applicability to typical environmental exposures",
        "Complexity in measuring DNA damage and repair"
    ],
    "evidence_strength": "low",
    "confidence": 0.40000000000000002220446049250313080847263336181640625,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "electromagnetic fields",
        "DNA damage",
        "radiofrequency radiation",
        "extremely low frequency",
        "comet assay",
        "genotoxicity",
        "DNA repair"
    ],
    "suggested_hubs": [
        {
            "slug": "who-icnirp",
            "weight": 0.8000000000000000444089209850062616169452667236328125,
            "reason": "Discussion of exposure levels relevant to cell phone use and base stations, relevant to international guidelines."
        }
    ]
}

Comments

Log in to comment.

No comments yet.