Washington: University of Minnesota researchers say that certain industries may be a significant source of plant-based oestrogens, called phytoestrogens, in surface water.
Civil engineering experts at the university’s Institute of Technology say that some of these phytoestrogens can be removed through standard wastewater treatment, but in some cases, the compounds remain at levels that may be damaging to fish.
Professor Paige Novak and her graduate student researcher Mark Lundgren came to this conclusion after studying wastewater streams from 19 different industrial sites in Minnesota and Iowa. The researchers analysed them for six phytoestrogens.
They found very high concentrations of these hormone-mimicking phytoestrogens -- up to 250 times higher than the level at which feminisation of fish has been seen in other research -- in the wastewater discharged from eight industrial sites, including biodiesel plants, a soy milk factory, a barbecue meat processing facility and a dairy.
They also found high concentrations of phytoestrogens in the water discharged by some municipal wastewater treatment plants.
Even thought the researchers have found that more than 90 percent of these compounds can be removed from water through standard treatment, sometimes 99 percent removal is needed to reach levels that are considered harmless to fish.
Plant-based phytoestrogens are naturally occurring but have been shown to function as hormone mimics and alter development and reproductive patterns in fish. These effects include decreased aggression, immunosuppression, and decreased testosterone production.
According to Novak, other oestrogens that cause similar effects have been linked to population-level collapse in fish.
"Many people have looked at human-related chemicals such as those in birth control pills as the primary source of estrogens in the water supply, but they have not looked at plant-based estrogens from a wide variety industries. Our research is the first study of its kind to provide a snapshot in time of what is going on in these industries. We hope that it can be used in planning new industrial sites and expansion of current sites," Novak said.
The researcher has revealed that some of these industrial facilities are in small towns without sophisticated wastewater treatment plants, and that there is potential for impact on fish and wildlife in these locations.
"Our nation needs to do some careful planning as we rapidly expand various plant processing industries. We need to include good wastewater treatment into our industrial plant designs. We also need to think broadly as we look for the causes of fish feminisation in various streams, rivers and lakes, as well as possible solutions," Novak said.
ANI
