In a study of 11 U.S. national parks, scientists found more than 1,000 tons of microplastics that came into these places with rain.
Because plastics are not biodegradable, they break down into micro-particles and penetrate the Earth’s atmosphere, soil, and water systems when they enter landfills. Janice Brahney, a lead author of the study, calls the process “the plastic spiral,” where some microplastic particles travel through natural systems for long periods of time.
The Brahne team discovered that so-called wet microplastics particles were most likely carried away in a storm from large urban areas and then “fell out” like precipitation elsewhere.
Although the effects of microplastics on the human body are still unknown, scientists are beginning to raise questions about public health issues about microplastic particles: they are small enough and can settle in the lung tissue, which will cause damage. A 2019 study showed that a person inhaled about 11 microplastic particles per hour in a city apartment.
Scientists also bind microplastic particles to fluctuations in the thermal properties of soil, leading to losses in plant life.