Direct and indirect effects of exposure to 900 MHz GSM RF EMF on CHO cell line: Evidence of bystander effect by non-ionizing radiation

Authors: Jooyan N, Goliaei B, Bigdeli B, Faraji-Dana R, Zamani A, Entezami M, Mortazavi SMJ

Year: 2019 Apr 1

Category: Environmental Research

Journal: Environ Res

DOI: 10.1016/j.envres.2019.03.063

URL: https://www.ncbi.nlm.nih.gov/pubmed/31036329

Abstract

Abstract

Introduction

The increasing global concerns regarding the adverse health impacts of exposure to radiofrequency radiation (RFR), especially from devices like mobile phones, have escalated scientific investigations into their biological effects. Unlike direct effects, non-targeted effects (NTEs) such as the bystander effect (BE) do not require direct exposure to manifest and are notably critical under low-energy radiations. While the NTEs of ionizing radiation are well-established, studies on non-ionizing radiation responses like BE are limited, emphasizing the significance of this research.

Materials and Methods

  • Chinese hamster ovary cells were exposed to 900 MHz GSM RFR with a specific absorption rate (SAR) of 2 W/kg for durations of 4, 12, and 24 hours using a specially designed cavity to ensure uniform field distribution and minimize unwanted RF exposure.
  • The study assessed various cellular responses including cell membrane permeability, redox activity, metabolic and mitotic cell death, DNA damage, and particularly, the induction of the bystander effect through medium transfer procedures.
  • Intra and extra cellular levels of reactive oxygen species (ROS) were measured to understand the molecular mechanisms behind RFR-induced BE.

Results

No significant changes were observed in the majority of the direct exposure metrics except after 24 hours of RFR exposure, which notably impacted clonogenic ability and caused a significant increase in olive moment in both directly exposed cells and bystander cells (through conditioned culture medium). This exposure duration also significantly elevated both intra and extra cellular ROS levels.

Conclusion

The study conclusively identified the induction of the bystander effect in cells treated with conditioned culture medium, marking it as a pioneering discovery in the field of non-ionizing radiation research. It also highlighted the crucial role of ROS in mediating both the direct and indirect effects of RFR, proposing ROS as a potential molecular agent in these effects. The findings underline the potential health risks associated with RF exposure, emphasizing the need for further research and safety considerations.

electromagnetic fields radiofrequency radiation bystander effect non-ionizing radiation ROS health risks cellular effects
← Back to Stats