LEAD POISONING

Abstract

Examination of the records of patients with lead poisoning admitted to the Children's Hospital of Philadelphia revealed a seasonal incidence in the onset of encephalopathic symptoms. Figure 1 shows the monthly distribution of onset of symptoms of the patients with frank lead encephalopathy admitted to this hospital. In constructing this figure only patients with frank encephalopathic symptoms of rather acute onset were counted; patients with latent or subclinical plumbism, usually discovered accidentally, who exhibited no obvious encephalopathic symptoms were not included. It is apparent from figure 1 that almost all of the cases occur during the late spring and summer months. Shelling and Hopper¹ commented on the same seasonal incidence of the cases studied in the Harriet Lane Home. We assumed that there was a real relation, probably causal, between the summer season and the increased severity of lead poisoning and planned experiments to examine the seasonal factors which