(photo credit: INGIMAGE)
Ben-Gurion University of the Negev researchers have developed a simple model for estimating the amount of natural estrogen from birth control pills in raw sewage and how concentrations change during wastewater treatment.
The study, published in the journal Science of the Total Environment, provides a model for producing accurate data on estrogens, which is relevant for regulators, environmental scientists and wastewater.
Doctoral student Pniela Dotan and Dr. Shai Arnon of BGU’s Zuckerberg Institute for Water Research and Prof. Alon Tal of BGU’s Swiss Institute for Dryland Environmental and Energy Research based their results on data from 61 wastewater plants published in previous reports. To develop their model, they considered information collected from various publications about biochemical oxygen demand (the amount of dissolved oxygen that must be present in water for microorganisms to decompose organic matter), natural estrogen concentrations, and discharges of raw sewage to wastewater treatment plants.
The effects on humans of estrogens excreted in the urine that washes into rivers and sewage systems is not certain, but environmentalists worry about harmful effects on male fish that can reduce their sperm production and thus the number of fish produced for food.
“This new model can predict likely natural estrogen concentrations in liquid waste or sewage discharged into a river or the sea from simple information about flow and biochemical oxygen demand data at a wastewater treatment plant inlet, which are commonly monitored and available,” the authors explained.
“This application is especially valuable since current models rely on estimating the concentrations of natural estrogens in raw wastewater, and direct measurement of natural estrogens in raw wastewater can be practically impossible in many developing countries due to the lack of expertise and funds,” they continued.
The researchers’ model was shown to produce more accurate results than existing tools because it is based on a simple linear equation, which plots the relationship between direct and indirect variables, as opposed to other modeling frameworks that require large datasets or census data.
The data are from a wide range of wastewater treatment plants from five continents and can be used for projecting concentrations of natural estrogens from a wide range of mixed domestic and industrial sources.
“The model should apply globally, as long as wastewater systems don’t contain significant contributions from industrial sources known for their high natural estrogen or biochemical oxygen demand content, such as dairy farms or food processing plants,” the researchers said.