Evaluating the Acute Toxicity of Estrogen Hormones and Wastewater Effluents Using Vibrio fischeri

ABSTRACT

Toxicity evaluation of environmental substances such as those in wastewater and contaminated water bodies has become an important part of environmental monitoring of pollution. The study evaluated the toxicity of estrogen hormones and the removal of toxicity in full-scale wastewater treatment plants (WWTPs) using the marine bacterium, Vibrio fischeri, and to determine if there is a correlation between the hormones and the toxicity in the effluents. Three different types of full-scale WWTPs were investigated and presence of estrogens in the treated wastewater was evaluated by enzyme linked immunoassay (ELISA). The toxicity of individual estrogens (E2, EE2, and a mixture of E1, E2, and E3) was investigated as well as influents and treated wastewater. The results revealed that all estrogen hormones had less than 50% inhibitions and fell in the Class II group that exhibits slight acute toxicity. The toxicity of the individual E2 hormone had higher inhibitions when compared to the individual synthetic EE2 and the mixture of the hormones. The toxicity results of the WWTP revealed that biological treatment can reduce the toxicity of the influent to an extent. The findings suggest that the residual estrogen contents as well as toxicity can be reduced in certain WWTPs.

Key Words:

• wastewater
• toxicity
• Vibrio fischeri
• ELISA
• estrogen hormones