The Air Quality Index Explained: What It Means and How to Stay Safe
By Adeel Hassan NY Times, Aug. 6, 2021
The Air Quality Index measures the density of five pollutants: ground-level ozone, particulates, carbon monoxide, nitrogen dioxide, and sulfur dioxide. It was established by the Environmental Protection Agency as a way to communicate to Americans the cleanliness of the air they are breathing each day. Read more




Over the past several weeks, NASA satellite measurements have revealed significant reductions in air pollution over the major metropolitan areas of the Northeast United States. Similar reductions have been observed in other regions of the world. These recent improvements in air quality have come at a high cost, as communities grapple with widespread lockdowns and shelter-in-place orders as a result of the spread of COVID-19.