Generation of • OH, O 2 •− , and H 2 O 2 in ultrapure water under 50-Hz ELF–EMF exposure

This study investigates the long-term generation of reactive oxygen species (ROS) in ultrapure water exposed samples (ES) to extremely low-frequency electromagnetic fields (ELF-EMF; 50 Hz, 1 mT) under controlled, external non-thermal conditions. The ROS hydroxyl radicals (•OH), superoxide radicals (O2•−), and hydrogen peroxide (H2O2) were quantified in over 1 year in ES relative to matched non-exposed samples (NES). The net ROS differences (ES minus NES) exhibited accelerating temporal trajectories that were well described empirically by exponential functions. This exponential behavior is interpreted as a descriptive temporal pattern rather than as evidence of a specific kinetic or autocatalytic amplification mechanism. The empirical exponential coefficients decreased in the order •OH > O2•− > H2O2, corresponding to progressively longer characteristic and doubling times for the respective ROS trajectories. These observations are compatible with the possibility that small ELF-EMF-associated perturbations of pre-existing ROS reactions could influence coupled reaction pathways over time, although the underlying mechanism remains unresolved. A mechanistic interpretation based on radical pair spin dynamics and secondary ROS cross-reactions is proposed, while excluding direct high-energy radiolytic pathways as an explanation. The findings are therefore considered within an exploratory, hypothesis-generating framework rather than as evidence of a demonstrated amplification mechanism. Although the observed temporal behavior of the generated ROS raises the possibility that weak ELF-EMF-associated perturbations could influence ROS dynamics in more complex systems, extrapolation to biological systems or human health remains speculative and requires direct experimental investigation. Further studies are required to evaluate the mechanistic basis and biological relevance of this framework.