PORPHYRIN PROFILES IN THE NESTLING EUROPEAN STARLING (STURNUS-VULGARIS) - A POTENTIAL BIOMARKER OF FIELD CONTAMINANT EXPOSURE

Porphyrin patterns in avian and mammalian tissues and/or excreta have been proposed as qualitative and quantitative biomarkers of exposure t o polyhalogenated hydrocarbons, heavy metals, and other environmental contaminants. However, no widely distributed terrestrial species has b een characterized as a suitable model in which to assess porphyrin pro files in the evaluation of environmental contaminant exposure. The Eur opean starling, whose nests can be readily established and manipulated on contaminated sites, has many qualities that accommodate controlled field research and that suggest its suitability for such assessments. In the present studies, we measured the total and individual porphyri n concentrations in liver, kidney, and fecal-urate excreta of nestling starlings from a noncontaminated field site from day of hatch through d 17 of the nestling period. Total as well as individual 8-, 7-, 6-, 5-, 4-, and 2-carboxyl porphyrin concentrations in liver, kidney, and fecal-urate excreta were readily detectable by high-performance liquid chromatography (HPLC) spectrofluorometric techniques and displayed ti ssue-specific patterns throughout the developmental period. Liver and fecal-urate porphyrin patterns were established by d 4 subsequent to h atch and remained constant through d 17 of development, whereas renal porphyrin profiles were constant throughout the entire developmental p eriod. In controlled field studies, nestling starlings were treated wi th either HgCl2 or hexachlorobenzene (HCB), and tissue and excreta por phyrins were extracted and evaluated. The findings suggest that the ne stling starling may serve as a suitable model species in which to moni tor the effects of field contaminant exposure to wildlife based on che mical-induced changes in tissue or excreta porphyrin levels.