[Lead poisoning in the school-aged child: results of a screening program using zinc protoporphyrin]

The results of a zinc-protoporphyrin (ZPP) screening in 1983 among first-grade schoolchildren in Hospitalet de Llobregat (Catalonia, Spain) are presented. Tap water in this industrial city comes from the Llobregat river and is extremely hard, with an excessive level of salts. At this time, Spanish gasoline had high levels of lead. The purpose of the study was to evaluate the effect of environmental pollution on subclinical lead poisoning. These were 428 children in the study, 67% of those eligible. Causes for non participation were being absent from school on the screening day or lack of parental consent for participation in the study. Only in two children levels of ZPP above 40 theta g/100 ml were found; both cases had iron deficiency anemia with low blood lead levels. Mean ZPP levels were somewhat higher in the Collblanc district, which suffers higher air pollution from street traffic, and in children living in houses built before 1940. The relevance and implications of these findings are discussed.