Two Albion College students, working alongside chemistry professor Kevin Metz, are two of 25 from across the country to gain Undergraduate Student Awards in Environmental Chemistry from the Division of Environmental Chemistry of the American Chemical Society (ACS).
Anna Miller, a biology major from Grand Haven who holds a concentration in environmental science, and Stephanie Sanders, a first-year chemistry major from Farmington, were students in Metz’s fall class that ran experiments on the uptake and impact of small particles of silver by Brassica rapa, plants such as turnips and mustard that have a complete life cycle of 44 days.
Metz became interested in the impact of silver on plants when he noted the makers of approximately 1,500 commercial products self-report the use of nanomaterials in their goods, with silver nanoparticles being used most frequently. Silver nanoparticles are of particular interest for their antimicrobial properties.
“These include things like socks, food wrapping like the plastic placed over fresh meat in a grocery store, baby bottle nipples, and the liners for washing machines and dishwashers,” Metz said. “The use of silver nanoparticles in socks could reduce the risk of athlete’s foot or the use of antimicrobial materials on a baby bottle is thought to reduce the risk of an oral infection.
“The problem is many studies have shown the silver nanoparticles come out of the products,” he added. “One study looked at six types of hiking socks and showed 90 percent of the nanoparticles came out in the first wash. The silver ends up in a wastewater stream.”
Metz continued that once the silver is in a wastewater treatment plant it tends to get settled out in the first step and that material is used a fertilizer on farms.
“There is risk of the silver nanoparticles being sprayed on crops or fields for vegetable production,” Metz said. “The ecosystem is based on microbial harmony, and if the microbes are being killed by the silver that could influence the plants negatively.”
After pulling the plants and washing them after 2 ½ weeks in soil, the plants did not exhibit any change in growth but there was a significant intake of silver. The consumption of silver by a human eating one of the Brassica plants could be harmful.
The fall experiments were hampered as the students fed the plants lethal amounts of silver. Miller and Sanders improved the amount of silver fed to the plants as they continued the study during the spring semester and the results they achieved were presented on a poster at the ACS national meeting in March that will likely be the starting point for future study.
“I came up with the idea for the experiment as a way to design a laboratory experiment that would have a real-world impact that students could connect to,” Metz said. “Our plan is to write our results as a laboratory experiment that other schools could use to get other places thinking about how nanoparticles impact the environment.”
Sanders still got the experience of talking about the Albion results with a scientist from Massachusetts who has studied plants’ intake of silver while growing in water during the ACS meeting. Metz maintains both Miller and Sanders also benefit from witnessing the interdisciplinary nature of science at a liberal arts setting like Albion.
“Anna’s primary research project is with biology professor Dan Skean,” Metz said. “We have students at Albion who are studying biology with aspirations to study environmental ecology or botany. To me, the interdisciplinary abilities of the students and collaboration between departments are the neat part to this project.”