Newspaper article St Louis Post-Dispatch (MO)

Male Turtles Are Feminized by Chemical Found in Plastics

Newspaper article St Louis Post-Dispatch (MO)

Male Turtles Are Feminized by Chemical Found in Plastics

Article excerpt

The turtles are in trouble. A chemical found in Missouri's rivers and streams can influence the sex organs of developing turtles, making males more like females, researchers say.

A pilot study conducted at the University of Missouri showed that the synthetic chemical bisphenol A or BPA, which is known to mimic estrogen and disrupt hormone levels in animals can alter a turtle's reproductive system after exposure in the egg. Turtles are perfect creatures for this type of study, because their sex is determined by the temperature of the environment during their development in the egg.

"Cool dudes or hot babes," explained Sharon Deem, director of the St. Louis Zoo's Institute for Conservation Medicine and a lead investigator on the study.

The researchers dropped a liquid form of the chemical onto hundreds of eggs that were incubated at cooler temperatures required to produce male turtles. A few months after they hatched, the turtles' sex organs were removed and studied. The male turtles had developed gonads that were closer to ovaries than testicles.

The BPA essentially overrides the temperature in determining the sex of the turtle, creating an animal that is probably unable to reproduce, Deem said.

The researchers used the same levels of BPA that were found in samples from Missouri waterways including Peruque Creek in St. Charles County, James River in Nixa and Perche Creek in Columbia. The estrogen-like chemical is found in plastics and is thought to contaminate more than 40 percent of U.S. rivers. Estrogen also enters the waterways through the urine of men and women, especially pregnant women and those taking birth control pills. Waste water treatment plants cannot fully remove hormones, sending them back into the natural water system.

The study on turtles is a good indicator of the overall health of the ecosystem because the reptiles live in oceans, rivers and on land, scavenging food from decaying plants and animals.

"We have some environmental issues that are impacting wildlife," Deem said.

The researchers from the university, the zoo, Westminster College and the U.S. Geological Survey recently received a $250,000 grant from the Mizzou Advantage research project to continue the study and compare results among fish, mice and turtles. …

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