He’s saying because your car gets worse mileage with ethanol, you’re spewing more pollution because you have to burn some more gallons to make the same trip.
Which ‘pollutant?’ If one considers CO2 a pollutant than the 12.6 lbs of CO2 from a gallon of ethanol is a lot less than the 19.6 lb from a gallon of octane (and associated CxH(2x_2)). Even if you took a 20% MPG hit for ethanol it still isn’t worse.