The petri dishes are stacked and separated by which have been viewed under the microscope, and those that still need to be studied.
The outside of each container identifies where along the river they were collected. Inside are filters containing the remnants of water that was dried and then removed of any remaining organic materials.
Tim Peternell is examining each sample in search of tiny fragments of a pollutant that will never break down – plastics.
“For the most part, microplastics (under the microscope) just look like little fibers … like seeing a thread off of your shirt,” says Peternell, a student at Missouri Southern. “We’ve found a few clear pieces in various shapes. Basically, we’re looking for things that don’t look like they’re organic.”
Are the findings discovered locally unusually high, about average or even low? Good question. At this point, it’s difficult to say.
While a number of studies have focused on the levels of microplastics found in the ocean and marine environments, studies in freshwater are limited – even more so when it comes to the Midwest United States.
Two environmental health and safety majors at Missouri Southern State University are working to change that.
Seniors Avery Cozens, of Rogers, Ark., and Peternell, of Arma, Kan., have undertaken the study for their Honors project, looking for the presence of tiny plastic fragments in the Spring River Watershed in Southwest Missouri.
“We’ve taken a two-direction approach,” says Dr. Teresa Boman, associate professor of biology and environmental health. “One student is focusing on the water component and the other on the sediments in the water; both are known spots where microplastics can potentially be found.”
The students – assisted by Boman, Dr. Rachel Heth, assistant professor of biology and environmental health, and Melissah Perkins, master instructor of biology and environmental health – began taking samples in December. They collected water and sediment from 16 different locations along Spring River.
“Tim, who is doing the water component, would stand in the river for 20 minutes to let water flow through a phytoplankton net, so we could get a better picture … more than just a ‘grab some water and see what’s there’ sample.
“While he was doing that, we were doing basic water parameters such as pH, conductivity and dissolved ogygen, and Avery was collecting sediments. He would do that over a 50-meter stretch of the creek, scraping sediment off the bottom.”
From each stop along the river, they brought back a one-liter jar of water and one liter of sediment. Now, the students have begun the lab work necessary to analyze the samples.
Using equipment the Environmental Health & Safety Department acquired last year through a MoExcels grant in combination with MSSU student research grant funding, Cozens and Peternell are hard at work in a first-floor lab in Reynolds Hall.
“Now that we’re back on campus, the work gets a little more intensive,” says Boman. “The water has to be put in a beaker to dry. From there, we do a digestive process, using a highly concentrated hydrogen peroxide to break down any organic matter that might be in it. Then we have to run it across a filter to capture whatever is left, then sift through to find any microplastics.”
Analyzing the sediment samples is work intensive as well, she says. Cozens must perform a two-step extraction process to extract plastic particles from the sediment. Both methods require a team effort.
“We collected sediment samples off the bottom of the stream bed, then ran the samples through a density separator to try to get the lighter particles to the top,” says Cozens.
Their initial research has indicated the presence of microplastics. Boman says fibers come off of clothes in washing machines and enter septic systems and wastewater treatment facilities. Microbeads, which are now banned in the U.S., do not go away and can still be found in the water.
“We have zero expectation of what should be in the Spring River Watershed because there are no studies,” she says. “Most studies are done in the ocean, so we don’t know what the ‘normal’ values are. Once we know they exist and how much, there are a lot of other directions we can go with our research.”
Keya Pandey, a senior at Joplin High School, has undertaken a similar study using water collected from Turkey Creek, and is utilizing the lab at Missouri Southern to study her samples.
When finished, Boman says she has every expectations the students will be able to publish their findings.
“This kind of study in freshwater is a newer approach,” she says. “There are papers, but mostly from other countries, or the authors focus on larger bodies of water – like reservoirs, lakes and major river systems.”