United Kingdom G/R.2 THE HAZARDS TO MAN OF NUCLEAR AND ALLIED RADIATIONS General report covers both somatic and genetic hazards associated with radiation, present and foreseeable levels of exposure, and an assessmentof the hazards in terms of associated actual and permissible levels. G/R.20 THE RADIOLOGICAL DOSE TO PERSONSIN THE UNITED KINGDOM DUE TO DEBRIS FROM NUCLEAR TEST EXPLOSIONS PRIOR TO JANUARY 1956 Summarizes measurementsoftotal beta activity and Sr® content of fallout at ground stations, in rain water and in the air over the United Kingdom during 1952-1955. Includes calculations of time-integrated gamma ray doses. G/R.30 RADIOSTRONTIUM FALLOUT IN BIOLOGICAL MATERIALSIN BRITAIN Describes methods for determination of Sr®™ in soils and material of the biological cycle; gives results of measurement effected in England up to Spring 1956. G/R.51 THE GENETICALLY SIGNIFICANT RADIATION DOSE FROM THE DIAGNOSTIC USE OF X-RAYS IN ENGLAND AND WALES-—A PRELIMINARY SURVEY Contains an analysis of number of X-ray diagnostic examinations performed per annum in England and Wales, and a subdivision obtained from five selected hospitals into types of examinations, and into age and sex of the patients examined. In addition, an assessment is made of the minimum dose received by the gonads in each type of examination, and the probability of reproduction as a function of age. The results show that it is unlikely that the genetically significant radiation dose received by the population of England and Wales from X-ray diagnosis amountsto less than 22% of that received from natural sources andit may well be several times greater than this figure. Most of this radiation is received in a few types of examinations, undergone by relatively few patients, and by foetal gonads in examinations during pregnancy. G/R.60 GENETIC RESEARCH IN THE UNITED KINGDOM Relevant programmes of genetic research in the United Kingdom and their investigators concerned are listed under the headings. (i) fundamental research upon mechanisms (ii) population structure (iii) quantitative data on human mutation G/R.60 (Add.1) G/R.100 SUGGESTIONS FOR RESEARCH IN RADIATION GENETICS General considerations are reviewed and a list of suggested programmes of research in the fields of (i) to (iii) is appended. THE DETERMINATION OF LONG-LIVED FALLOUT IN RAIN WATER Describes radiochemical procedures for the determination of Sr®, Sr®, Cs'37, and Ceactivities in the rain water. G/R.103 MODIFICATION OF IMMUNOLOGICAL PHENOMENA AND PATHOGENIC ACTION OF INFECTIOUS AGENTS AFTER IRRADIATION OF THE HOST Evidence is given that whole body irradiation before the repeated injection of antigen both diminishes the peak-concentration of antibody and delays in time the appearance of the peak. The lowest efficient dose was 25 r. The tolerance of heterogeneous skin grafts or bone marrow cells has been also shown after irradiation; the duration of inhibition of immune response is proportional to dose received. , G/R.104 SOME DATA, ESTIMATES, AND REFLECTIONS ON CONGENITAL AND HEREDITARY ANOMALIES IN THE POPULATION OF NORTHERN IRELAND Presents an extremely detailed and thorough medicogenetic survey of the population of Northern Ireland using data accumulated over a number of years, 195 abt