Assess the effects of POP mixtures present in the food on the endocrine system of marine mammals. Effects of these mixtures on steroid synthesis in adrenals and gonads will be studied in vitro. Further, hormone mimicking effects of contaminant mixtures will be studied. Contaminant receptor binding and responses of the contaminant-receptor complex are studied using estrogen/androgen receptor binding assays in combination with reporte gene assays.