Infant leukaemia after in utero exposure to radiation from Chernobyl.

There has been no documented increase in childhood leukaemia following the Chernobyl accident. However, different forms of childhood leukaemia may not be equally susceptible to radiation carcinogenesis. Infant leukaemia is a distinct form associated with a specific genetic abnormality. Outside the former Soviet Union, contamination resulting from the Chernobyl accident has been highest in Greece and Austria and high also in the Scandinavian countries. All childhood leukaemia cases diagnosed throughout Greece since 1 January 1980 have been recorded. Here we report that infants exposed in utero to ionizing radiation from the Chernobyl accident had 2.6 times the incidence of leukaemia compared to unexposed children (95% confidence interval, 1.4 to 5.1; P approximately 0.003), and those born to mothers residing in regions with high radioactive fallout were at higher risk of developing infant leukaemia. No significant difference in leukaemia incidence was found among children aged 12 to 47 months. Preconceptional irradiation had no demonstrable effect on leukaemia risk at any of the studied age groups.

Blood lipids in Greek adolescents and their relation to diet, obesity, and socioeconomic factors.

A study of blood lipid levels in adolescent students in rural and urban areas of Greece was undertaken. Blood samples were drawn from 307 adolescents aged 12 to 18 years attending two rural and two urban high schools of different socioeconomic level (urban/lower, urban/higher). Obesity among adolescents had statistically significant detrimental effects on the lipids profile, being associated with higher total and low-density-lipoprotein (LDL) cholesterol and lower high-density-lipoprotein (HDL) cholesterol levels. Adolescents living in urban areas had substantially and significantly higher levels of total and LDL cholesterol, but among urban residents, higher socioeconomic status was associated with lower levels of total and LDL cholesterol. There was no clear evidence that total, LDL, and HDL cholesterol levels were substantially affected by qualitative aspects of diet as evaluated through a food frequency questionnaire. The results of this study indicate that the traditional Mediterranean pattern of living and eating in the rural areas of Greece is associated with a favorable lipid profile in adolescents, which may explain the very low incidence of coronary heart disease (CHD) in these areas. In urban areas lipid profiles are satisfactory in children of high socioeconomic status but unfavorable in children of low- to middle-class families, which are known to be at higher risk for CHD.

Birth weight and handedness in boys and girls.

The association between selected demographic variables and birth weight on the one hand and a composite hand preference score based on seven hand tasks (each performed twice) on the other was investigated in a sample of 1387 male and female schoolchildren aged 5 to 10 years old. In multiple regression models left-handedness was significantly more common among boys and among children of better educated mothers and tended to decrease with age. No association was found with respect to urban or rural residence or birth order. Increased birth weight was associated with right-handedness in boys but with left-handedness in girls, and the birth weight by sex interaction term was statistically significant (p = 0.037). The demographic associations in the present study are compatible with those reported previously. The different associations of birth weight with hand preference in boys and girls indicate that the prenatal hormonal factors that affect brain lateralization and handedness are qualitatively or quantitatively different in the two sexes and may be differentially associated with birth weight.

Survival from childhood leukemia depending on socioeconomic status in Athens.

One hundred and twenty children first diagnosed as having acute leukemia between 1988 and 1992 in Athens, Greece, were followed until May 15, 1993. The socioeconomic status of the children's families was assessed by means of paternal occupation, paternal schooling, maternal schooling, ownership of a car, ability to choose a private medical facility and freedom in the choice of the attending physician. The analysis was done by proportional-hazards modelling, controlling for age and gender. All six socioeconomic indicators, alternatively evaluated, showed that fatality rates were higher in the lower socioeconomic groups, although nominal statistical significance was reached for only one of them. With respect to family ownership of a private car, the fatality rate ratio between children of families who own a car and children of families who do not was 0.29 with a 95% confidence interval of 0.13-0.62 (p = 0.002). These results suggest that in Greece, socially disadvantaged children have a less favorable survival from childhood leukemia.

Age of exposure to infections and risk of childhood leukaemia.

PIP: Between January and August 1992 in Greece, researchers conducted telephone interviews with parents of children with leukemia (136 cases, most in Attica [Athens and its environs] and the others on the island of Crete) and with parents of children not afflicted with leukemia (187 controls) to determine whether childhood leukemia may be a result of a subclinical infection at an earlier age. They controlled for place of residence when they conducted the multiple logistic regression analyses. They used attendance at a day care facility as a proxy for earlier infection because children come in close contact with each other at day cares, thereby exposing them to many infectious agents. Children who attended a day care had a lower relative risk of developing leukemia than those who did not attend day care (.67), but attendance did not have a significant protective effect. It did appear to have a significant protective effect for children who attended day care during infancy (for at least 3 months during the first 2 years of life), however, (relative risk = .28; p = .03). Significance remained even when the researchers considered different operational definitions of early attendance. Exposure to magnetic fields appeared to have a protective effect also against the development of childhood leukemia, but this effect did not reach significance (p = .07). The relative risk for 100 m from an electricity substation was 0.35. There was a slight, but insignificant increase in the relative risk for children living close to power lines, however (1.19 for 5 m; p = .63). Significant risk factors included young age at diagnosis and mothers with less than high school education.^ieng