The effect of No2 on people 0.5 ppm-can be smelled 5 ppm- begin to affect the respiratory system 20-50 ppm- strong odor, one's eyes become irritated, damage to the lungs, liver and heart 150 ppm with 3-8 hour exposure- serious lung problems can occur The U.S. National Air Quality Standard is 0.053 ppm annual arithmetic mean In a city as Los Angeles, about 750 tons of NOx (NO NO2)are put into the atmospheric every day, about 500 tons form internal combustion engines and 250 tons from electric power plantsThe effect of NO2 on people: • 0.5 ppm — can be smelled • 5 ppm — begin to affect the respiratory system • 20 - 50 ppm — strong odor, one’s eyes become irritated, damage to the lungs, liver and heart • 150 ppm with 3 – 8 hour exposure — serious lung problems can occur The U.S. National Air Quality Standard is 0.053 ppm annual arithmetic mean. In a city as Los Angeles, about 750 tons of NOx (NO + NO2 ) are put into the atmospheric every day, about 500 tons form internal combustion engines and 250 tons from electric power plants