Experimental plumbism

Abstract

Experimental chronic lead poisoning was produced by feeding metallic lead in the form of bullets to pigeons. The symptoms are characterized by a prompt loss of body weight and appetite, gradual depression, loss of equilibrium, diarrhea, increased crop peristalsis with regurgitation of contents, wing drop (anatomically corresponding to drop-wrist in man), paralysis of legs, marked emaciation and death at the end of 21 days (mean). At autopsy, the principal lesions observed are marked atrophy of the skeletal musculature everywhere, and sometimes darkening of mucosa of the large intestine and cloaca; unabsorbed lead bullets, if any, being found in the gizzard.

The results on 63 animals to date may be briefly summarized as follows: The lethal dose of lead was found to be about 0.16 gm. per kilo; time of death in fatal cases was 21 days; time of recovery in survival cases was 26 days to 8 months; lead absorbed in fatal cases was 85 per cent.; concentration of lead in tissues of fatal cases was about 0.075 per cent.; and the current of lead, about 0.0103 gm. per kilo per diem for 83 days to 0.02 gm. per kilo per diem for 25 days; the maximal loss of body weight in fatal cases was 40 per cent., in surviving pigeons 8 per cent.; the first appearance of loss of body weight in all animals was demonstrable at end of 2 to 4 days after administration and the greatest loss of body weight occurred at the end of 20 days; loss of body weight proceeded or was parallel with diminished food intake apparently due to loss of appetite from sickness; the daily food intake was 3.9 gm. in fatal cases and 18 gm. in survival cases; the normal food intake being 23 gms.