Jan 01 2004 - Physiology Web Site

Impact of Enviornmental Lead Pollution on the Physiology of Birds

By J.C. George
Department of Zoology , University of Guelph, Guelph, Ontario, Canada N1G 2W1
Fax: (519) 767-1656; email: jgeorge@uoguelph.ca

ABSTRACT

Lead in the environment occurs in different forms in the soil, water, air and food. In high concentrations and through chronic exposure human and animal health could be adversely affected. Besides hunting and predation, environmental lead poisoning is considered the major cause of mortality in ducks and geese which form the main component of the waterfowl population of North America and certain other parts of the world. Decades of hunting using lead shot has resulted in massive accumulations of lead in waterfowl habitats. Lead poisoning is caused by spent gun shot which are ingested by waterfowl with food and grit. The general signs of lead poisoning are lethargy, anorexia, loss of weight and weakness of voluntary muscles leading immobility, starvation and death. The birds also become anemic and suffer from diarrhea. Studies have shown that lead has profound effects on the structure and metabolism of the gastro-intestinal tract, liver kidney, heart, small arteries and arterioles, flight muscle, nerves, and other tissues indicating the mechanism of its action. Studies on the effects of experimentally-induced lead poisoning in captive wild birds as well as birds used as laboratory models, are also reviewed with a view to obtaining a better understanding of the effects of lead on the target organs and tissues, and their physiological bases.

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