Continuous recording of intrapulmonary "compressed air" as a sensitive noninvasive method of measuring bronchial obstruction in guinea pigs.

The method presented is based on whole-body plethysmography. The apparatus consisted of two chambers (a = respiratory, b = body chamber) separated by a tight water-filled rubber cuff which was fixed around the head of the animal. Experiments were performed under constant gas conditions: temperature 30 degrees C, 100% relative humidity, the volumes of the two chamber being identical.

[A comparative morphological and enzyme-histochemical study of experimental pneumoconiosis and experimental allergic-hyperergic pulmonary granuloma (author's transl)].

Six endotracheal applications of 15 milligrams of cadmium sulfide (CdS) given to rats at weekly intervals induce pneumoconiosis with massive adhesions. The same quantities of lead sulfide (PbS) given under the same conditions have much less effect, causing only the formation of fairly small fibrous nodules. The tissue reactions to CdS and PbS were studied morphologically (light and electron microscope) and enzyme-histochemically.

[To the behaviour of cadmium and lead in children with a different cadmium or lead burden].

An epidemiological study of 413 randomly chosen children in age of 2--14 years living in an industrial town is presented. According to their place of residence they were either burdened with cadmium from a forge or with lead from the traffic. The different burden was refelcted not only in the blood lead level but also in blood cadmium level respectively.

[The relationships between blood lead, erythrocyte count, blood hemoglobin concentration and age in children (author's transl)].

With increasing age of the children and increasing hemoglobin, hematocrit and serum protein levels, the lead concentrations of the blood in the children dropped. By contrast, high lead concentrations in blood correlate with low MCV and high erythrocyte values. The possible causes are discussed.

[Relationships between immissions of plumb and zinc and the levels of plumb, zinc and cadmium in blood, urine and hair in children (author's transl)].

In children from an industrial area with a high degree of lead, zinc and cadmium pollution, the lead levels in blood and hair increased with increasing lead fall-out, and the cadmium concentration in the urine increased with increasing zinc fall-out. Children from the center of town presented significantly higher lead values in the blood and hair samples and, significantly lower urine lead concentration than those children investigated, living in the peripheral districts of the industrial town. The lead content of blood and hair samples corresponded to the various lead immission levels encountered.

[The influencing factors of selection of collective upon the assessment in epidemiological studies in the example of blood lead levels in children (author's transl)].

In a study of blood lead levels in 1719 children from 2 industrial areas, both with high but differing lead pollution, it is shown how the selection of the collective can influence the results of an epidemiological study. A representative statement on the lead exposure for all children living in a circumscribed area, is not possible if the children are selected according to previous diseases or, for that matter, according to medical criteria of any kind. Also, a selection only upon voluntary basis stemming from parental decision, does not bring correct results.