Detection of estrogenic activity from kraft mill effluents by the yeast estrogen screen

Estrogenic activity of kraft pulp mill effluents (P. radiata, E. globulus and mixed -50% E. globulus and 50% P. radiata) was evaluated by the yeast estrogen screen assay. The estrogenic activity values were relatively low, ranking between 1.475 and 0.383 ng/L of EE2 eq. (Estrogenic equivalent of 17 alpha-ethynylestradiol), where the highest value corresponds to the E. globulus effluent and the lowest value to the P. radiata effluent. Analysis by solid phase extraction (SPE) and gas chromatography-mass spectrometry (GC-MS) of chemical compounds present in all three effluents detected at least five major groups of organic compounds, corresponding to fatty acids, hydrocarbons, phenols, sterols and triterpenes. Comparison of analytical and biological data suggests that sterols could be the cause of the estrogenic activity in the evaluated effluent.