[Influence of school environmental factors and learning on pupils' health].

This study is a part of a comprehensive research conducted at 10 schools of different education types (general educational school, specialized gymnasiums, language schools, colleges, lyceums) that are situated in Sofia. A relationship between the factors that characterize school and the training environment, and the health status of pupils was established by using currently available statistical methods. The findings show that the discrepancy between the school and training environment and the sanitary requirements and standards affect both the general and school age-specific morbidity rates in pupils.

Nutrition and respiratory health in children in six Central and Eastern European countries.

Background: The results of studies on the effect of nutrition on respiratory diseases are inconsistent. The role of nutrition in children's respiratory health was therefore analysed within the cross sectional Central European Study on Air Pollution and Respiratory Health (CESAR).

Method: A total of 20 271 children aged 7-11 were surveyed in six European countries.

Methodological approaches to the analysis of hierarchical studies of air pollution and respiratory health--examples from the CESAR study. Central European Study on Air pollution and Respiratory Health.

Objectives: Many studies of air pollution and health are carried out over several geographical areas, and sometimes over several countries. This paper explores three approaches to analysis in such studies: a non hierarchical model, a two-stage analysis, and multilevel modelling. Illustrations are given using a preliminary subset of data from the CESAR study.