[On the epidemiology of recurrent and chronic bronchopulmonary diseases-an examination of about 18000 children. 1. Planning and organization of the investigation (author's transl)].

The planning and organization of an epidemiological investigation is reported to find out the frequency of chronic nonspecific lung diseases (CNSLD) in childhood as a whole and in special groups of age. By investigating regions with different air pollution we tried to study the influence of air pollution on the frequency of childhood lung diseases. Therefore, we examined nearly 5000 children in the city of Halle and in the districts of Quedlinburg, Merseburg and Bitterfeld. The children belonged to the age-groups 5.-6., 8.-9., 11.-12. and 14.-15. years of life in nearly the same number. The investigations were performed by different groups of investigators. However, by equal terms of reference and uniform evaluation of the results by two of us the results of the four districts are comparable with each other.