Table 4.

Regression estimation.

	Air quality				Public health
	CO	NO	SO	PM 2.5
Vegetation	−0.487**	−0.985	0.357	−0.823*	−0.253**
Industrialization	1.854*	0.574*	0.743*	−2.922	0.548*
Urbanization	0.275***	0.091	0.330	0.435**	0.938

^{***, **, and *}indicate the level of significance at 1, 5, and 10%, respectively.

CO, NO, and SO represent carbon, nitrogen, and sulfur, respectively, whereas public health is the death rate due to air pollution.