A fresh study from an inter-disciplinary staff demonstrates that microplastics have been rapidly increasing in water environments for years and are directly related to the rise in global cheap manufacturing since the 1950s. The results provide insight into how plastic move and spread in water conditions, which the experts believe will be crucial for developing long-term remedies to reduce waste.
A new study from an inter-disciplinary group of Penn State experts reveals that microplastics have been rapidly increasing in water environments for years and are directly related to soaring global cheap manufacturing since the 1950s. The findings provide insight into how microplastics move and spread in freshwater environments, which the researchers believe will be crucial for developing long-term solutions to reduce pollution.
The research is currently accessible online, and it will appear in the December issue of Science of the Total Environment.
” Natural and environmental engineering associate professor and corresponding author” Nathaniel Warner,” a few studies examine how microplastics change over time.” Our study, which was the first to track microplastic levels in freshwater sediment from before the 1950s to today, demonstrates that concentrations rise in line with plastic production.
Microplastics are tiny plastic particles that range in size from one micrometer, or 1/100 of the width of a human hair, to five millimeters, which is about the size of a pencil eraser. They can either be produced directly by manufacturers or in larger plastics that break down into smaller pieces. For this study, the team examined freshwater sediment cores from four watersheds in Pennsylvania: Kiskiminetas River, Blacklick Creek, Raystown Lake and Darby Creek.
Contrary to the team’s expectations, the study found no correlation between population density or land use and high levels of microplastics.
According to Lisa Emili, associate professor of physical geography and environmental studies at Penn State Altoona and co-author of the paper, what we thought would be important turned out to be not the driving forces in microplastic variation across sites.
The researchers also expressed surprise to learn that while microplastic accumulation increased from 2010 to 2020, it decreased.
Emili said,” This may be a preliminary finding that warrants further investigation, but this could also be a result of increased recycling efforts.”
Between 1980 and 2010, plastic recycling efforts by the U.S. Environmental Protection Agency increased significantly. Although plastic production also increased, the percentage of recycled plastic increased from less than 0.3 % in 1980 to nearly 8 % in 2010.
Additionally, Raymond Najjar, a professor of oceanography and a co-author on the paper, said that this study could shed light on the “missing plastics” paradox. Because estimates indicate that between 7 and 25 000 kilotons of plastic enter the ocean each year, only about 250 kilotons are thought to be floating on the surface, making this paradox difficult to understand for scientists.
” This suggests that estuaries, especially tidal marshes, may trap river-borne plastics before they reach the ocean”, said Najjar, who previously published in Frontiers in Marine Science on simulations of filter estuaries. This may explain why there is less plastic in the ocean’s surface than what is expected, given the input from rivers.
According to Warner, these findings indicate that as more plastic is consumed, there will continue to be more microplastics in both water and sediment.
The long-term effects are just beginning to be studied, according to Warner, who said that people are ingesting plastic when they eat and drink and inhaling it when they breathe. However, we must discover ways to reduce consumption and exposure and how to release less plastic into the environment.
Emili claims that an inter-disciplinary team is necessary to succeed in studies like this one.
” This research shows Penn State’s broad expertise, bringing together a team from three campuses, five colleges and five disciplines”, Emili said. ” We brought together complementary skillsets from our fields of chemistry, engineering, hydrology, oceanography and soil science”.
Initial funding for this research project came from a seed grant from the Institute of Energy and the Environment.
According to Emili,” That funded project really served as an “incubator” for our ongoing research into the fate and transport of microplastics in freshwater environments, with a particular emphasis on coastal areas.”
Najjar agreed and expressed his desire for a more thorough examination of estuaries’ plastics ‘ ability to trap water.
” We have known for a long time that estuaries heavily process river borne materials, like carbon, sediment and nutrients, and this processing has a big impact on what eventually reaches the ocean”, Najjar said. We need more than just a modeling study and a single core, but I believe estuaries could be working in a similar way to plastics. We need to consider the likely sources and sinks of plastics for a given system, such as rivers, atmosphere, estuarine sediment and marshes”.
Warner added that he wants to look at how microplastic composition and types have changed over time and how the risks for health have changed as well.
In addition to Emili, Najjar and Warner, the other Penn State researchers who contributed to the study include, Jutamas Bussarakum, lead author and doctoral student in the Department of Civil and Environmental Engineering, William Burgos, professor in the Department of Civil and Environmental Engineering, Samual Cohen, who graduated with their master’s degree in geography earlier this year, Kimberly Van Meter, assistant professor in the Department of Geography, Jon Sweetman, assistant research professor in the Department of Ecosystem Science and Management, Patrick Drohan, professor in the Department of Ecosystem Science and Management, Jill Arriola, assistant research professor in the Department of Meteorology and Atmospheric Science, and Katharina Pankratz, who graduated with their doctorate in civil and environmental engineering earlier this year.
This research was supported by the United States National Science Foundation, Penn State’s Commonwealth Campus Center Nodes ( C3N ) Program, and the Institute of Energy and the Environment.
