23 ranged from 20 to 26 months, with an average of 22.4 months. To determine whether or not some pattern in physique characterized these children with retarded osseous development, several physical measurements (from the 1959 study) on them and on their sibs were compared (Table 13). These anthropometric data suggested twotrends. First, the weight rankings corresponded to chronological age rankings and notto statural rankings. Second, the lack of synchrony in rankings of several measurements was noticeable in those children who were shorter than their younger sibs. This contrasted with the uniform ranking of al] measurements in those whose statural ranking corresponded with the chronological age ranking. It might be speculated from these limited observations that these children were exposedto radiation at a particularly vulnerable age and that the resulting retardation in osseous development led to failure in statural growth. On the other hand, itis not possible to exclude completely the possibility that some process unrelated to radiation damage was responsible for the retardation in skeletal development. ADULT ABNORMALITIES Table 14 is a compilation of the various physical abnormalities noted in the adult group during the 1959 and 1960 surveys. No abnormalities are included for 1960 in the unexposed group because this group was not examined in the 1960 survey. This table does not showanysignificant differ- ences between the abnormalities noted in the ex- malities, and in the older group 41%. Specific findings maybe summarizedasfollows. Electrocardiographic Findings 1. Rhythm. In the younger group of exposed subjects, all had normal rhythm. One abnormality of rhythm was seen in a member of the younger unexposed group.In the older groups, arrhythmia occurred in 3 of 14 exposed individuals andin 4 of 29 unexposed. 2. Conduction Times. Few abnormalities were seen. No individual in either the exposed or the unexposed group had prolonged auriculoventnicular conduction time (P-R interval) above normal. Several subjects had the shorter conduction time of 0.12 sec; this is considered normal. The intra- ventricular conduction time (QRS interval) was prolongedin several subjects. In the younger unexposed group, the ORSinterval was 0.10 to 0.11 sec in one subject, sufficient to be considered right bundle branchblock. In the exposed population the intraventricular conduction time was prolonged to 0.12 sec in only one individual, age 81, who had a marked degree of hypertensive and arteriosclerotic cardiovascular disease and cardiac enlargement. Among 29 individuals in the older unexposed group, two showed intraventricular conduction times of 0.12 sec without the typical QRScomplex of bundle branch block. In all other subjects the intraventricular conduction time ranged from 0.06 to 0.09 sec in the younger groups and 0.08 to 0.09 in the older. 3. Electrical Axis Deviation and Electrical Posi- fion of the Heart. There were fewvariations. The posed and in the unexposed populations. Results of special examinations are discussed below. CARDIOVASCULAR SURVEY Table 15 YOR ARCHIVES Electrocardiographic Abnormalities (Percent Incidence in Younger and Older Age Groups) Exposed The cardiovascular findings may be found in the table of physical abnormalities (Table 14). The incidence of various electrocardiographic ab- normalities is shown in Table 15. The population was divided into a younger group, aged 20 through 49, and an older group, aged > 50. In the exposed population, the younger group of 24 people showed no major abnormalities, but of the 14 older people 29% showed one or more abnormahities. In the unexposed population, amongthe younger group 15% had one or more abnor- Age Abnormality Rhythm A-V I-V RST T wave Unexposed Age 20-49 (24)* 2950 (14) 0 21 12 0 0 0 7 7 21 Age 20-49 (35) 2 2 4 2 11 Age 250 (29) 14 3 7 14 34 *Number examined. me ee ee ee