The tranquil mornings at Lake Tahoe are marked by the gentle sound of waves and the lively calls of birds, all under the glow of the rising sun. This picturesque scene, however, hides a growing concern as scientists investigate the levels of microplastic pollution affecting this iconic water body.
Collaborative research efforts involving the Desert Research Institute (DRI) and the University of Nevada, Reno (UNR) are underway to understand the extent of microplastic contamination in Lake Tahoe. Monica Arienzo, an associate research professor at DRI, explains that microplastics range from five millimeters down to just one micron in size.
“So that’s basically like the size of a pencil eraser … down to about the size of bacteria,” Arienzo described.
These particles originate from a variety of sources, posing a challenge in identifying their origins, as Arienzo noted. The research aims to trace these plastic particles’ paths and destinations within the environment.
Carina Seitz, research assistant professor at UNR, builds upon a previous study that highlighted Lake Tahoe as having the third-highest concentration of microplastics among lakes globally. Her research focuses on how larger plastic pieces degrade into microplastics and their subsequent impact on the lake’s ecosystem.
This study uniquely concentrates on microplastics smaller than 20 microns, which are nearly invisible to the naked eye. Li Li, an associate professor of public health at UNR, underscores the importance of this research for understanding potential health impacts on humans.
“It’s very important for us to measure these very small, very tiny microplastics, because compared to the larger ones, they are more likely to get into the human body and more likely to stay there for a longer time,” Li stated.
Once inside the human body, microplastics can circulate throughout, potentially penetrating barriers like the blood-brain barrier, Li explained. Despite these findings, Li is not overly concerned about current microplastic levels in Lake Tahoe’s water, which serves as a drinking water source.
“The level we find in the Lake Tahoe water is too low to cause significant exposure to human beings. My personal understanding is the level we find so far is not enough to trigger public concern over the Reno area,” Li said.
Li emphasizes that while microplastics themselves might not pose immediate health threats, the chemicals they may carry are concerning. He points out how microplastics can bind with environmental chemicals, like pesticides, potentially increasing health risks over time.
Arienzo stresses that reducing plastic use is crucial for addressing plastic pollution, as recycling alone won’t suffice. “I’m a big believer that we will not recycle our way out of this problem of plastic pollution. I believe that the best thing we can do to reduce plastic pollution and microplastics in our waterways, in our environment, is to eliminate the use of plastics,” she said.
In response, the City of South Lake Tahoe has banned single-use water bottles for commercial vendors since April 2024. Laura Patten from Keep Tahoe Blue (KTB) reports positive outcomes from this policy, noting fewer plastic bottles during cleanups.
Patten highlights initiatives such as installing water refill stations and educating businesses. KTB also utilizes a cleaning robot, BEBOT, to remove plastics trapped under the sand, emphasizing efforts in prevention.
“One of the issues is, if you don’t capture microplastics before they break down, they’re really impossible to remove,” Patten explained. KTB’s strategy centers on cleanups, understanding cleanings, and advocacy for preventive measures.
Despite the challenges, Seitz remains hopeful about human capacity for positive environmental change. “I feel optimistic. I think that people can do [sic] great changes if they are willing. I am a strong believer that there are always alternatives to have progress and development in a way that is safe for our environment and for our health,” Setiz said.
