Assessing microplastic contamination in Icelandic soils: Insights from remote, agricultural, and urban environments

Microplastic (MP) contamination is a growing concern across many environments. However, research on MP accumulation in remote soils remains limited. This study investigated MP abundance in remote soil in western Iceland, with agricultural and urban soils as references. The MP was extracted and measured using state-of-the-art methods, capturing types, sizes, and shapes. Results showed that MP was present in all samples, with the lowest average count and mass observed in the remote samples (857 (±561) counts kg^-1, corresponding to 64.37 (±47.96) μg kg^-1) and the highest in the urban samples (26,206 (±25,345) counts kg^-1, corresponding to 2175 (±1385) μg kg^-1), showing that increase in anthropogenic activity gives increasing MP concentrations. In the remote samples, the particles were primarily medium-sized (median = 67 μm), lightweight polyester fragments. This study also investigated the influence of soil parameters such as water content, bulk density, and particle size on MP retention in remote soils. However, no other significant correlations were found when relating the count and mass to soil parameters.