Authors: Stone Smith, Ben Belt
Mentors: Sally Rocks
Insitution: Utah Valley University
Microplastics are particles less than 5 mm in length. These particles act as a vector for heavy metal and carcinogens, which have negative effects on human health. Often invisible to the naked eye, microplastics are extremely mobile and have been found in the most extreme parts of the planet, from the peak of Mount Everest to depths of the Mariana trench. Because microplastics are readily transported via air and water, microplastics have been found in every location exposed to wind or rain. However, one place that is sheltered from wind and rain are caves. In some subterranean environments, the earth acts as a natural filter of the water that descends into caves. It is suspected that caves will have lower levels of microplastics present in their environments compared to surface environments. However, another mechanism for microplastic introduction is human activity. Humans utilize plastics in relatively all synthetic items. Everything from clothing to packaging to regular household items employs the use of plastics, which can abrade to release microplastics. The goal of this research is to determine if caves with high levels of human visitation have higher concentrations of microplastics than caves with little to no human visitation. Analysis of subterranean water samples will reveal if microplastics are invading cave environments regardless of human activity, and through what mechanisms. A consequence of microplastic pollution in cave environments is the capture of plastic particles within mineral matrices. As mineral rich water evaporates in caves, the minerals left behind form speleothems that could capture plastic particles and thus preserve them (e.g. stalactites, stalagmites, soda straws, etc.). With a better understanding of the presence or absence of microplastics in caves, efforts can be made to minimize plastic accumulation and prevent microplastics from entering the geologic record of the cave.