Mean concentrations of target EEs measured by GC-MS and EEQs of different samples.

<p>The estrogen equivalent quantity (EEQ) was defined as the sum of the concentration for each individual compound after multiplying an estradiol equivalency factor derived from previous studies <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0095597#pone.0095597-Behnisch1" target="_blank">[17]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0095597#pone.0095597-Api1" target="_blank">[73]</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0095597#pone.0095597-Liu1" target="_blank">[76]</a>. E₁, E₂, E₃, EE₂, and DNOP were under detection limits.