However, CO2 has never been regulated as a pollutant under the Clean Air Act and does not pose any direct threat to human health unlike NOx, SO2 and mercury.
NOx poses a significantly stronger risk to human health than SO2
mnli hypothesis: NOx poses a significantly stronger risk to human health than SO2 premise: However, CO2 has never been regulated as a pollutant under the Clean Air Act and does not pose any direct threat to human health unlike NOx, SO2 and mercury.