How often does a heart beat? For a zebrafish, it depends on the water it's swimming in. Ellen Du Pre, professor of biology at Central College, is working with four students, as well as biology colleague Nicole Palenske, to study the effects of triclosan on heart rate. The tiny fish, which can be as small as an eyelash when newly hatched, is transparent, and the students can easily count the heart beats under a microscope.
Triclosan is a chemical used in disinfecting soaps, and it has made its way into tap water systems. In preliminary research, Du Pre and students have learned that when fish are exposed to certain levels of the chemical—specifically the levels found in drinking and surface water— heart rate goes down significantly. This may be linked to a decrease in metabolism, which some scientists have suggested may be a contributing factor for some of the high childhood obesity rates in the U.S.
"It does make me nervous," she says. "I don't think people realize all the chemicals we are being exposed to. I don't think our bodies are prepared to deal with them all."
The research done by Du Pre and her students was recently chosen from more than 3,500 submissions by the National Council on Undergraduate Research for presentation at the 2013 conference. The students will present at the University of Wisconsin-La Crosse in April.
"This is very exciting. The work of these Central College students has been recognized for its unique contribution to this field of study."