Occupational and Environmental Health: Recognizing and Preventing Disease and Injury - Multiple Choice Questions - Learn & Prevent

Nonionizing radiation refers to a type of energy on the electromagnetic spectrum that does not have enough energy to ionize atoms or molecules. This means it cannot cause direct damage to DNA or cell structures. However, it can still have an effect on body tissues by causing thermal effects, meaning it can heat up tissues. Out of the options given, microwaves are the most closely associated with thermal effects due to their ability to effectively heat up water molecules in tissues. Radio waves and infrared radiation can also cause thermal effects, but they are lower on the electromagnetic spectrum and have less energy compared to microwaves. Extremely low frequency (ELF) fields do not have enough energy to cause thermal effects, making them the least associated with thermal effects on body tissues.