Table 1 Relationships between weekly wet plastic deposition rates, dust, population statistics, and air-mass trajectories.

Pearson correlation coefficients (r) and model coefficients of determination (r2) between wet plastic deposition rates and potential drivers. Full model selection is based on the Akaike Information Criterion (AIC), and parameters included are shown in bold. NA, not applicable.

National park or wildernessDust (r)Total population (r)Total populated area (r)Distance (r)Mean wind speed (r)Full model (r2)
Grand Canyon, AZ0.160.70***0.56**0.80***0.410.69***
Wind River Range, WY0.74***0.320.310.34*0.30.77***
Craters of the Moon, ID−0.110.050.43**−0.120.010.21**
Rocky Mountain, CO0.27*0.35**0.120.180.050.20**
Joshua Tree, CA0.16−0.45−0.240.96**0.63*0.71*
Uinta High Wilderness, UT0.2−0.48−0.320.080.110.86
Canyonlands, UT0.44*0.01−0.160.050.250.19
Indian Peaks, CO0.77**0.420.66*0.29−0.150.99**
East River, CO0.58***−0.11−0.12−0.05−0.040.34***
Great Basin, NV0.41*0.51**0.170.48**0.180.59***
Bryce Canyon, UT−0.13−0.020.001−0.06−0.1NA

*P < 0.1; **P < 0.05; ***P < 0.01.