Until the beginning of the 20th century, the levels of electromagnetic fields and radition to which people could be exposed were very low. Modern industrial development, and in particular technological advances associated with the growth of electrical power generation and transmission systems, have resulted in increasing levels of exposure of people to a complex mix of artificially elevated electromagnetic fields that span a wide frequency range. In recent years concern has increased about possible health effects that might result from exposure to non-ionizing radition (NIR) and particularly about cancer. This report provides information on the sources of NIR, summarizes guidelines and standards for limiting exposure and makes recommendations for research.