32 Alert Network may be used to identify any intrusion of unexpected quantities | of radioactivity in the environment and is not intended to be used to estimate ‘human exposure. There are other routine monitoring activities besides this nationwide network that provide information for specific. areas and specific radionuclides. The Radiation Alert Network is adequate for the purpose intended. Gross beta activity in air, as indicated by air filter samples collected at ground level, indicate to monitoring and surveillance personnel, whether there should be increased sampling of milk, water and vegetation in that area. The specific quantities and kinds of radionuclides found in the samples may then be used to estimate population exposure. The current radiation surveillance and monitoring networks in the U. S. provide quite adequate data upon which scientists may evaluate the extent of contamination of the environment and the potential exposure to man. For your information, a summary of the various Radiation Surveillance Networks ae is enclosed which identifies the major radiation monitoring programs in the United States. In addition to these programs there are numerous research studies or programs which provide a vast amount of additioal information ‘and data relating to radioactivity levels in the environment. Question DA If a man absorbs a curie of radioactive substance, will it kill him? Answer SA The biological effects of a curie of radioactive substance taken into the body will depend upon many factors and may be expected to differ from