Endocrine disruptors increase after rain

Posted on June 26, 2010


Some chemical contaminants that enter freshwater systems are known to be endocrine disruptors – in other words, they have the capacity to interfere with the physiology of aquatic organisms  by mimicking or blocking hormones.  Even when concentrations of individual contaminants are too low to have a measurable impact, endocrine disruption can still result from continuous exposure to a mixture of chemicals, making it important to study the effects of several contaminants at the same time.  Swiss researchers used liquid chromatography coupled with a mass spectrometer to measure the concentrations of a range of endocrine disrupting compounds in wastewater and in water taken from theGlattRiverin an industrial area nearZurich.  In treatment plants, removal rates for most types of endocrine disruptor were high, but in some cases, levels of endocrine disrupting compounds actually increased, presumably due to chemical transformation in the wastewater.  Removal efficiency was highest in plants where activated sludge treatment was followed by sand filtration.  When river flows increased as a result of heavy rainfall, flows of endocrine disruptors also increased and  there was no evidence for pollutant dilution.  The observed increase was probably due to the fact that when rainfall was high, treatment plants were unable to handle the extra capacity and were forced to discharge raw wastewater directly into the river.

Reference:  Jonkers, N., Kohler, H-P. E., Dammshauser, A. & Giger, W.  2009.  Mass flows of endocrine disruptors in the Glatt River during varying weather conditionsEnvironmental Pollution 157, 714–723.

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Posted in: physiology, pollution