Appendix Table A.1.

Regression Results for EC

$$\text{log}(\text{Personal}\mathrm{E}\mathrm{C})={\mathrm{\beta }}_{10}+{\mathrm{\beta }}_{11}\text{log}(\text{WorkArea}\mathrm{E}\mathrm{C})+{\mathrm{\beta }}_{12}(\text{Smoking})+{\epsilon }_{ijk}$$ (Equation 1)
Work Area	0.99a
Smoking	0.17a
Constant	0.05
Equation R2	0.64
$$\text{log}(\text{WorkArea}\mathrm{E}\mathrm{C})={\mathrm{\beta }}_{20}+{\mathrm{\beta }}_{21}(\text{Terminal Size})+{\mathrm{\beta }}_{22}(\mathrm{P}\&\mathrm{D})+{\mathrm{\beta }}_{23}(\text{Shop})+{\mathrm{\beta }}_{24}(\text{Ventilation})+{\mathrm{\beta }}_{25}\text{log}(\text{Yard}\mathrm{E}\mathrm{C})+{\mathrm{\beta }}_{26}(\text{Job})+{\mathrm{\gamma }}_{\mathrm{i}\mathrm{j}\mathrm{k}}$$ (Equation 2)
Terminal Size	0.01a
P&D Drivers	0.002a
Mechanics	0.002
Ventilation	− 0.09a
Yard Background	0.71a
Job	2.11a
Constant	− 0.21a
Equation R2	0.64
$$\text{log}(\text{Yard}\mathrm{E}\mathrm{C})+{\mathrm{\beta }}_{30}+{\mathrm{\beta }}_{31}(\text{Relative Humidity})+{\mathrm{\beta }}_{32}(\text{Temperature})+{\mathrm{\beta }}_{33}(\text{Wind speed})+{\mathrm{\beta }}_{34}(\text{Interstate})+{\mathrm{\beta }}_{35}(\text{Industrial})+{\mathrm{\beta }}_{3(6-9)}(4\text{Regional Dummies})+{\eta }_{ijk}$$ (Equation 3)
Relative Humidity	− 0.004a
Temperature	− 0.01a
Wind speed (kph)	− 0.11a
Interstate Distance (0–1)	−0.30a
Industrial Land Uses	0.01a
Region 1 (Midwest)	0.51a
Region 2 (Northeast)	0.84a
Region 3 (South)	1.08a
Region 4 (West)	0.68a
Constant	NAb
Equation R2	0.51

^aIndicates significant at 5% level.

^bNA indicates not available.