Blyes and fet: a preliminary understanding between effects and total estrogenic activity on surface waters

Abstract

Endocrine disrupting chemicals (EDCs) are included in a range of substances and are present in practically all environmental matrices, generally at low concentrations. For the occurrence evaluation of these substances, several in vitro tests are employed, among of them Bioluminescent Yeast Estrogen Screening (BLYES), which measures the total estrogenic activity in EEQ. However, this assay is not able to provide information about adverse effects to aquatic organisms. In order to observe aquatic communities effects, organic extracts of surface water samples from rivers and reservoirs of São Paulo state with results above the detection limit in BLYES (> 0.1 EEQ) were performed with embryonic assays with Danio rerio. The methodology was conducted according OECD 236, to verify acute effects such as: absence of heart beats, absence of somites, no tail detachment and coagulated embryo. Embryonic malformations were evaluated, such as: reduction of organism size, cardiac and vitelline edema, spine curvature and reduction of heart beating, which are characteristics of chronic effects. Among the 21 tested samples, 24% showed acute effects for Danio rerio and 14%, chronic effects. The effects observed probably would be associated with EDCs and/or other contaminants that may bind to the receptor in BLYES assay. The information obtained by embryonic assay with Danio rerio was suitable to show the effects of these groups of contaminants of the organic extracts and would complement the BLYES response. Accomplishing tests to evaluate effects on embryo reproductive system to establish a correlation between estrogenic activity and acute and chronic effects observed on FET is necessary.