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Students Study Health Impacts of Contaminants Emitted by Cars

May 22, 2017
PAH researchers Marissa DePolo and Adam Harris
PAH researchers Marissa DePolo and Adam Harris

A team of heath science and biology students is studying the health effects of polycyclic aromatic hydrocarbons (PAHs), molecules found in coal and tar deposits and emitted from cars, incinerators, and forest fires. Biology student Adam Harris and health science student Marissa DePolo are looking at how PAHs affect frogs that are native to Africa and have chambered hearts like humans. This could lead to an understanding of how the molecules impact human health.

Their findings showed that two PAHs, Phenanthrene and Fluoranthene, do in fact influence heart function in chambered hearts.

“We expose our larvae to different amounts of our PAHs and then take videos of their hearts. To analyze them, we count the atrial and ventricular beats and take note if they are beating too fast, too slow, or not in sync,” said DePolo. “When we first exposed our larvae to these PAHs, we noticed atrial-ventricular blockage as the stages progressed. This is because the PAHs inhibit the action potential within the heart and as the atrium contracts, there is not enough energy transmitted to the ventricle, which disables its ability to contract.”

From these initial findings, the team decided to continue testing PAHs on the frogs. “These findings are based on exposing our larvae to realistic amounts of PAHs, which you can easily find within our environment. After analyzing the cardiac rhythms of the realistic exposure to our PAHs, we noticed a significantly slow heart rate. For future directions with our research, we would like to observe if the PAH-induced cardiac effects are reversible, does PAH exposure lead to reduced vascular development, and how diesel particles with a mixture of PAHs affect cardiac function,” said DePolo.

What exactly do DePolo’s and Harris’ findings mean for humans in a real-world setting? “As humans, we are exposed to these PAHs frequently, so this is something we should be concerned about. It is interesting to learn more about them and be able to apply this data to humans,” said Harris.

While both members of the team found the research engaging, the learning consisted of lessons outside of the lab as well. “I learned to never sell yourself short or think you’re not capable of learning and adapting to new and challenging experiences,” said DePolo. “With my busy schedule and the initial complexity of this research, I felt I was in over my head and was not sure if this was something I could handle; however, I stuck with it and learned so much.”

This research is supported in part by New Hampshire-INBRE through an Institutional Development Award (IDeA), P20GM103506, from the National Institute of General Medical Sciences of the NIH.