Tissue levels of lead in experimentally exposed zebra finches (Taeniopygiaguttata) with particular attention on the use of feathers as biomonitors

We tested experimentally whether zebra finch feathers can be used as a biom onitor for lead pollution, and we examined whether lead exposure influences the accumulation of zinc into feathers. Two groups of eight adult male zeb ra finches were dosed with, respectively, 0 and 25 ppm lead as lead acetate in their drinking water. After 30 days, lead-treated zebra finches accumul ated significantly higher lead concentrations in brain, fat, kidney, liver, muscle, testes, and regrown outer tail feathers than control individuals. Lead levels in regrown outer tail feathers were significantly higher than i n original outer tail feathers in the exposed group. The concentration of l ead in original (not regrown) fifth tail feathers at the end of the experim ent was significantly higher than lead levels in the original outer ta-il f eathers. Our results indicate that lead in regrown feathers originates both from internal deposition and external contamination through the excretion of the uropygial gland during preening. Lead levels in regrown feathers wer e significantly correlated with levels in liver, kidney, and muscle, sugges ting that feathers can be used as a biomonitor for lead. We found that lead had an influence on the metabolism of zinc. Zinc concentrations in the reg rown feathers were significantly lower in the lead-treated group although z inc levels in the liver did not differ significantly. Moreover, lead and zi nc concentrations in the feathers were significantly negatively correlated.