This sub-series includes items from the Los Alamos National Laboratory; various government agencies, including US Senate Committees; the Departments of Environmental Protection Agency, Energy and the Department of Health, Education and Welfare; the US Navy. Subjects cover a wide range of matters including weapons proliferation, the use and regulation of nuclear energy and the monitoring of radiation. Folder 1: Los Alamos National Laboratory. Inter-office memorandum from JR Oppenheimer to Rotblat dated 5 May 1944 informing Rotblat of his appointment to the Coordinating Council, typescript, not signed; two photocopies of letter from Oppenheimer to Dr Enrico Fermi of the Metallurgical Laboratory, University of Chicago about radioactively poisoned foods, with reference to Edward Teller's opinion; covering letter about material about accelerator transmutation of waste, not included, 20 March 1992. Folder 2 Various Government Agencies: Leaflet about USA Government Fulbright travel grants; US Embassy, London: invitation to exhibition of data communications equipment and systems; US Senate Committees on: Government Operations, covering letter forwarding papers 'Peaceful Nuclear Exports and Weapons Proliferation' and Armed Services, pre-hearing policy questions and opening statement of Secretary of Energy Designate Federico Peña, photocopies from Peña to Committee; Office of Senator Edward M Kennedy, press release statement on prevention of nuclear testing; US Atomic Energy Commission, request for copy of paper presented at Pugwash Conference, Proceedings of the 20th Pugwash Conference; US Nuclear Regulatory Commission, Risk Assessment Review Group and Reactor Saftey Study (WASH-1400); US Mission to NATO, conference on dismantlement and destruction of chemical and nuclear weapons. Folder 3: Department of Commerce. Request for papers; National Bureau of Standards returning copy of Chadwick's MSc thesis on the use of ionisation chambers for measurement of high-intensity pulse beams of electrons and x-ray; National Institute of Standards and Technology (NIST) from John H Hubbell about the International Radiation Physics Society and activities of the NIST, with copies of articles and papers enclosed, annotated by Hubbell. Folder 4: Environmental Protection Agency and Department of Energy. Papers on medical use of ionising radiation and requests for reprints and sending of abstracts; request for Rotblat to review draft environmental statement about US Nuclear Power Export Activities, copy of summary sheet enclosed; information on hourly readings for radiation releases from tests in the late 1960s. Folder 5: Department of Health, Education and Welfare. Information about genetic damage in standard experiments on plants and micro-organisms; National Center for Radiological Health, National Institutes for Health, Public Health Service: administrative arrangements for Rotblat as a Public Health Service fellow, organisation and position changes in the service; press release about Aspirin-Myocardial Infarction Study; correspondence with the Director of the National Cancer Institute about radiation risk estimates based on Hiroshima and Nagasaki Survivors, including the Director's comments. Folder 6: US Navy. Embassy of the USA, Office of Naval Research, Branch Office, London, later Department of the Navy: forwarding of publication US Atomic Energy Commission Annotated Bibliography on Fall-Out Resulting from Nuclear Explosions, included; information about "hypocaloric feeding and radiation tolerance"; covering letters about requests for and forwarding of publications, not included; Office of the Naval Attaché, building of 156 inch synchro-cyclotron at Liverpool, request by Rotblat for copy of technical report on the design of cyclotron magnets; US Naval Hospital, samples and experiments on tissue dosge and thorotrast; US Naval Radiological Defense Laboratory, preparation of paper on environmental factors in aging, life span shortening and carcinogenesis.