Table 3.
Effects of wind speed, distance from the fence line, and interactions of wind speed and distance from the fence line on six metals for each metal recycler (MR).
| Metal | Parameters | MR1 | MR2 | MR3 | MR4 |
|---|---|---|---|---|---|
| Fe | Intercept | 0.950 ± 0.116 (p < .001) | 0.861 ± 0.152 (p < .001) | 0.780 ± 0.149 (p < .001) | 0.947 ± 0.286 (p < .001) |
| Distance | −0.560 ± 0.043 (p < .001) | −0.163 ± 0.0.015 (p < .001) | −0.385 ± 0.047 (p < .001) | −0.102 ± 0.029 (p = .001) | |
| Wind speed | −0.008 ± 0.031 (p = .791) | −0.007 ± 0.051 (p = .891) | 0.060 ± 0.040 (p = .147) | −0.060 ± 0.0.077 (p = .440) | |
| Overall R2 | 0.852 | 0.753 | 0.582 | 0.308 | |
| Mn | Intercept | 0.914 ± 0.099 (p < .001) | 0.885 ± 0.141 (p < .001) | 0.796 ± 0.133 (p < .001) | 1.064 ± 0.335 (p < .001) |
| Distance | −0.547 ± 0.046 (p < .001) | −0.160 ± 0.015 (p < .001) | −0.371 ± 0.042 (p < .001) | −0.080 ± 0.033 (p = .022) | |
| Wind speed | 0.008 ± 0.034 (p = .806) | −0.016 ± 0.052 (p = .753) | 0.055 ± 0.036 (p = .135) | −0.098 ± 0.091 (p = .292) | |
| Overall R2 | 0.822 | 0.739 | 0.618 | 0.173 | |
| Ni | Intercept | 0.811 ± 0.122 (p < .001) | 0.814 ± 0.137 (p < .001) | 0.908 ± 0.115 (p < .001) | 0.550 ± 0.444 (p = .225) |
| Distance | −0.484 ± 0.045 (p < .001) | −0.163 ± 0.015 (p < .001) | −0.393 ± 0.036 (p < .001) | −0.053 ± 0.044 (p = .243) | |
| Wind speed | 0.036 ± 0.033 (p = .283) | 0.001 ± 0.051 (p = .988) | −0.001 ± 0.031 (p = .992) | 0.042 ± 0.122 (p = .732) | |
| Overall R2 | 0.796 | 0.784 | 0.697 | 0.044 | |
| Pb | Intercept | 0.776 ± 0.157 (p < .001) | 0.840 ± 0.149 (p < .001) | 0.634 ± 0.339 (p = .067) | 0.805 ± 0.202 (p < .001) |
| Distance | −0.507 ± 0.057 (p < .001) | −0.148 ± 0.014 (p < .001) | −0.353 ± 0.107 (p = .002) | −0.139 ± 0.020 (p < .001) | |
| Wind speed | 0.051 ± 0.042 (p = .231) | 0.001 ± 0.047 (p = .985) | 0.120 ± 0.092 (p = .199) | −0.016 ± 0.055 (p = .772) | |
| Overall R2 | 0.725 | 0.755 | 0.205 | 0.592 | |
| As | Intercept | 1.594 ± 0.274 (p < .001) | 0.858 ± 0.152 (p < .001) | 1.121 ± 0.089 (p < .001) | 1.027 ± 0.758 (p = .196) |
| Distance | −0.383 ± 0.125 (p = .008) | −0.165 ± 0.052 (p < .001) | −0.411 ± 0.028 (p < .001) | −0.054 ± 0.076 (p = .493) | |
| Wind speed | −0.209 ± 0.072 (p = .011) | −0.007 ± 0.052 (p = .895) | −0.063 ± 0.025 (p = .015) | −0.060 ± 0.208 (p = .778) | |
| Overall R2 | 0.543 | 0.752 | 0.825 | 0.037 | |
| Cr | Intercept | 1.301 ± 0.172 (p < .001) | 0.857 ± 0.144 (p < .001) | 0.968 ± 0.097 (p < .001) | 1.053 ± 0.405 (p = .017) |
| Distance | −0.487 ± 0.044 (p < .001) | −0.164 ± 0.014 (p < .001) | −0.4207 ± 0.031 (p < .001) | −0.093 ± 0.032 (p = .008) | |
| Wind speed | −0.097 ± 0.045 (p = .041) | −0.003 ± 0.049 (p = .944) | −0.006 ± 0.026 (p = .824) | −0.074 ± 0.112 (p = .517) | |
| Overall R2 | 0.826 | 0.770 | 0.788 | 0.304 |
Notes. Multiple linear regression analysis was performed with normalized ratios of metals as dependent variables. Wind speed (m/s) and distance from the fence line (m) were used as independent variable. Interaction terms between wind speed and distance from the fence line were not included due to insignificant effects for all models. an increase of 100-meter distance from the fence line decreases the slope estimate of distance with standard errors. an increase of 1 m/s of wind speed changes in the slope estimates with standard errors. Significant estimates and standard errors are shown with bold fonts.