Analysis of environmental endocrine disrupting chemicals using the E-screen method and stir bar sorptive extraction in wastewater treatment plant effluents.

Endocrine disrupting chemicals (EDCs) have become a major issue in the field of environmental science due to their ability to interfere with the endocrine system. Recent studies show that surface water is contaminated with EDCs, many released from wastewater treatment plants (WWTP). This pilot study used biological (E-screen assay) and chemical (stir bar sorptive extraction-GC-MS) analyses to quantify estrogenic activity in effluent water samples from a municipal WWTP and in water samples of the recipient river, upstream and downstream of the plant. The E-screen assay was performed on samples after solid phase extraction (SPE) to determine total estrogenic activity; the presence of estrogenic substances can be evaluated by measuring the 17-beta-estradiol equivalency quantity (EEQ). Untreated samples were also assayed with an acute toxicity test (Vibrio fischeri) to study the correlation between toxicity and estrogenic disruption activity. Mean EEQs were 4.7 ng/L (+/-2.7 ng/L) upstream and 4.4 ng/L (+/-3.7 ng/L) downstream of the plant, and 11.1 ng/L (+/-11.7 ng/L) in the effluent. In general the WWTP effluent had little impact on estrogenicity nor on the concentration of EDCs in the river water. The samples upstream and downstream of the plant were non-toxic or weakly toxic (0