where does good ozone come from
Bad Ozone-In the Earth s lower atmosphere, near ground level, ozone is formed when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources react chemically in the presence of sunlight.Ozone at ground level is a harmful pollutant. Ozone occurs naturally in the Earth s upper atmosphere (the stratosphere), where it shields the Earth from the sun s ultraviolet rays. 2  At ground-level, ozone is an air pollutant that can harm human health.