Scientists at Saint Louis University made a surprising discovery recently when they found a large amount of tiny plastic particles, known as microplastics, in a cave in Missouri that had been closed to people for over 30 years.
These findings raise concerns about how widespread plastic pollution has become, reaching even the most remote and untouched places.
Microplastics are tiny pieces of plastic smaller than 5 millimeters. You find them in oceans, lakes, rivers, and now, surprisingly, in caves.
Elizabeth Hasenmueller, a scientist leading the research, decided to explore Cliff Cave in Saint Louis County, Missouri, an untouched area closed to visitors since 1993.
The researchers picked this cave to be sure that any microplastics they found weren’t coming directly from people visiting the cave.
What they found was unexpected! Microplastics were everywhere in the cave, especially near the entrance and in the dirt on the cave floor.
When floods occurred, more microplastics were brought into the cave by the floodwater, showing that these tiny pieces of plastic were coming from the environment outside the cave.
Interestingly, when the team looked at the water in the cave, they discovered microplastics were almost 100 times more concentrated in the sediment than in the water.
This suggests that after a flood, microplastics in the water settle down into the sediment and stay there for a long time, maybe even decades, affecting the environment and creatures living there.
Despite being far away from human activity, the presence of microplastics in the cave suggests that residential areas nearby might be adding to the microplastics in the cave system.
Previous studies already show that where there are more people, there are usually more microplastics. The findings of this study are alarming because they reveal that our plastic use is affecting even the most isolated and undisturbed places on Earth.
What can we do about it? Elizabeth Hasenmueller suggests that being mindful of our plastic use can help. Avoiding plastics, like synthetic textiles in clothing, could reduce the amount of microplastic pollution.
However, she acknowledges that doing so is not easy given how common plastic materials are in our lives. A large-scale move away from synthetic clothing and a reduction in overall plastic production and consumption would be more impactful.
The tiny plastic particles could be harmful to the creatures living in the cave, including bats and amphibians. They have been living in this delicate habitat, and microplastics could disrupt their homes and lives.
This calls for more research to understand the level of threat posed by microplastics to these unique cave ecosystems and to find ways to protect them from such emerging contaminants.
In conclusion, the unexpected discovery of microplastics in Cliff Cave is a stark reminder of the pervasiveness of plastic pollution, reaching even secluded and untouched areas.
This should motivate us to be more mindful of our plastic use and to find ways to protect fragile habitats from the unseen invaders that are microplastics.
Scientists published the findings in the journals, Science of the Total Environment and Water Research.
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