1.3 O3
Ozone is an oxidant species formed predominantly from nitrogen dioxide and non-methane volatile organic compounds in the atmosphere.1,3 Peak season AQG and interim target levels were set based on the pollutant-attributed increase in all-cause non-accidental mortality, with moderate certainty evidence, and respiratory mortality, with low certainty evidence. 24-hour levels were set based on all-cause non-accidental mortality, with high certainty evidence.