Electromagnetic spectrum (EMS) is the range of frequencies of electromagnetic radiation (EMR). In general, EMR can be classified into ionizing or nonionizing radiation (NIR), based on their energy possessed to knock electrons off atoms that it interacts with. Ionizing radiation holds a great number of energy to knock off electrons and ionize the matter, whereas NIR does not possess enough energy to ionize atoms or molecules. Ionizing radiation can be further divided into five types, namely, alpha-particles, beta-particles, gamma-ray, X-rays, and neutron particles. NIRs are part of EMS encompass the wavelength (> 100 nm), low photon energy (< 12.4 eV) portion of the EMS from 1 Hz to 3 x 10(15) Hz. NIR is divided into four regions, namely, static electric and magnetic field, extremely low-frequency filed, radiofrequency, and microwave radiation and optical radiation. NIR can be from both natural (e.g., sunlight) and man-made sources (e.g., wireless communications devices). EMR exposures can be divided into three categories, which is high-level, medium-level, and low-level exposure. High-level radiation exposure can cause damage to the body, and the affected cells cannot repair fast enough with a dose that may quickly kill the exposed person. EMR is hazardous to all living organisms because its effects are latent, painless, and cumulative. The current review is to summarize the effect of EMR exposures on physical and mental health.
