Southeast Michigan has first 'Ozone Action Day' of 2021 View Comments Friday is the first Ozone Action Day of 2021 in southeast Michigan, according to officials with the state and an association of municipal governments. Michigan Department of Environment, Great Lakes and Energy said its latest Air Quality Index is orange, meaning there are elevated levels of ozone in the air over the region. As a result, the air could cause problems for children, senior citizens and people with asthma. Ozone is natural and man-made gas found in the Earth's upper atmosphere. And while it blocks harmful ultraviolet rays from the sun, breathing it in can cause serious health problems.