Recent papers, published in the journals Science of the Total Environment and Water Research and authored by researchers from Saint Louis University with student involvement in data publication, reveal the discovery of elevated microplastic concentrations within a Missouri cave system inaccessible to human visitors for three decades.
Flooding Enhanced Microplastic Concentration in the Missouri Cave System
Dr. Elizabeth Hasenmueller's team, along with students, detected significant microplastic levels in Missouri's Cliff Cave, which has been inaccessible to the public since 1993.
Microplastics are plastic particles under 5.0 mm and are present in various environments. While research has mainly focused on surface water settings, Hasenmueller aimed to explore microplastic contamination in subsurface environments like caves and groundwater.
Flooding was identified as a factor contributing to increased microplastic movement within the cave system. The team found microplastics both near the cave entrance and in the sediment, with sediment containing nearly 100 times more microplastics than the water.
Furthermore, flooding was observed to enhance the diversity and abundance of microplastics in cave water, with deposited materials remaining in cave sediment long after water levels receded.
Despite the cave's isolation from human access, its proximity to residential areas suggests potential human contributions to microplastic contamination, consistent with prior research indicating population density's role in microplastic presence. Hasenmueller recommends personal mindfulness regarding plastic use and encourages reducing synthetic textile consumption.
Microplastics pose a threat not only to the cave environment but also to the wildlife residing there, including bats and amphibians. Further research is needed to assess the impact on cave ecosystems and to protect these fragile habitats from emerging contaminants like microplastics.
Tracking Microplastics in the Ocean
Microplastics, plastic debris smaller than 5 millimeters, are a pervasive and concerning environmental issue. They originate from various sources, including the breakdown of larger plastic items and microbeads found in personal care products.
These tiny plastic particles enter the ocean through rivers and wind, spreading globally through the ocean circulation system. They have been discovered in oceans, seas, beaches, sea ice in the Arctic, and even on the ocean floor, posing a threat to marine life and entering the food chain.
Once in the ocean, microplastics degrade into even smaller particles called nanoplastics and accumulate in marine organisms, potentially impacting their health. Microplastics have been found in various wildlife, tap water, sea salt, bottled water, and fish consumed by humans.
Their effects on human health are still being studied. Besides health concerns, microplastic pollution has significant economic consequences, as it affects seafood, reducing the efficiency of aquaculture and fisheries.
To address the challenge of understanding and managing microplastic data, the National Oceanic and Atmospheric Administration (NOAA) created the NCEI Marine Microplastics Portal. This portal provides easy access to a database containing comprehensive information on global microplastics, including their occurrence, distribution, and quantity.
Data contributors from worldwide research cruises and fieldwork have made this resource possible. Researchers and the public can access and download data in various formats, making it a valuable tool for studying and addressing microplastic pollution.
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