New research suggests hiking boots and gear are polluting wilderness areas with microplastics

The expedition and the initial surprise

The study, titled “Return to Lake Tear (RTLT),” was organized by Adirondack Hamlets to Huts and Evergreen Business Analytics.. It was motivated by the surprising results of a 2023 expedition in which participants took water quality measurements along the entire Hudson River..

Given its position in the upper Hudson River basin, researchers had anticipated that Lake Tear of the Clouds (“Lake Tear”) would not be affected by microplastic pollution.. Instead, the 2023 expedition found an unexpected $9.45$ microplastic particles per ml in the lake.

For comparison, the highest microplastic concentrations observed along the Hudson in 2023 were $21.42$ and $28.94$ particles by $\text{milliliters}$ at North Creek and Glens Falls, respectively.

Given the low level of human activity in the Lake Tear area, researchers initially hypothesized that microplastic pollution was largely due to airborne deposition.

Comparative sampling and findings

To test the airborne deposition theory, the RTLT 2025 expedition added a control location: moss pond. Moss Pond is only a short distance from Lake Tear and is located at an almost identical elevation (Lake Tear in $4,293\; feet$moss pond in $4,252\; feet$), meaning both should be similarly affected by air pollution.. But unlike Lake Tear (a popular hiking destination), Moss Pond does not have a trail system and therefore has significantly less foot traffic..

The expedition took surface samples at the outlet of Moss Pond, followed by samples near the outlet of Tear Lake, andtThe laboratory findings were conclusive.

The average concentration of microplastics in Lake Tear was found to be $16.54$ particles per mla value significantly higher than the 2023 find. However, Moss Pond was found to have an average concentration of only 0.73 particles per ml. The significantly lower concentration at remote Moss Pond suggests that air deposition at both sites is very low.. The higher values ​​at Lake Tear, an order of magnitude higher, are likely due primarily to foot traffic..

Implications for hikers

The study concludes that hikers unknowingly contribute to the accumulation of microplastics in the ecosystem through the degradation of consumer products, clothing, footwear and equipment.. This aligns with external research showing that polymers and additives in outdoor recreation equipment are a major source of contaminants in high-traffic natural areas..

This problem is compounded by the growing popularity of the High Peaks region; It took 87 years for the official Adirondack 46ers roster to reach 7,630 members, but just 13 years later, that number has more than doubled to more than 16,000..

What comes next?

The findings then raise the question of what practical corrective actions can mitigate this contamination. The authors suggest that, at a minimum, the outdoor community should promote the use of natural fiber clothing and more durable footwear (e.g., hard rubber soles instead of soft rubber) when practical. Simple practices like wearing low-drape outer layers and monitoring shoe degradation would go a long way.

Additionally, hikers must strictly adhere to Leave No Trace principles, ensuring that all items, especially single-use plastics, are carried away to prevent them from degrading and releasing more microplastics into the ecosystem.