Trace Elements in Small Mammal Hair

Excesses and deficiencies of environmental trace elements can result in pathological conditions for animals including humans living in a given environment. In some of these cases the environmental level of the trace element has been correlated with hair level of the trace element. Subpathological but extra-optimal levels of certain elements may influence animal distribution and occurrence and these levels may be reflected in hair. Some trace elements (Pb, Hg, Cd and others) are important pollutants and their levels in the environment are generally increasing. High environmental Pb levels have been shown to correlate directly with Pb levels in pigeon feathers, and preliminary analyses indicate the same conclusion for Hg in pheasant feathers. It seems reasonable to expect hair might likewise provide a sensitive environmental monitor. Before the role of hair in trace element management can be determined, it must be shown if there is a species-specific hair trace element complement, or if all species in a given environment show essentially the same hair trace elements. Many analyses of human hair trace elements have been made, but results are inconsistent due to large differences in diet and the application of cosmetics. Populations of mice and shrews in the same limited habitat would be less subject to such variables. With species of known home-range size and food habits, it could be asserted that the animals caught in the same traps during the same trapping period represent one small segment of the environment. Differences in their hair trace elements would thus be due to species differences in food habits and metabolism. Project Number 170