LAS VEGAS (KLAS) — Measurements gathered by Clark County confirm that air pollution has dropped since Las Vegans began staying home.

Pollutants from cars on the road have dipped, and traffic is noticeably less crowded, according to a Monday news release from the Department of Environment and Sustainability.

The county measurements show a one-third decrease in nitrogen dioxide and particulate air pollution from February to March. While February had 16 days with “moderate” air quality, March had only one “moderate” day.

In mid-March, satellite images showed the effect across the southwest US:

Meteorologist Paul Fransioli said, “We are seeing reductions in PM2.5—small particulate matter—and nitrogen dioxide (NO2) when you compare data from the first half of March to the second half.”

The county notes that this drop coincided with the resort corridor shutdown and locals complying with stay-at-home orders.

Measurements were taken at a station just south of Palace Station and a station at Jerome Mack Middle School, which is near Sahara Avenue and Lamb Boulevard.

Particulates — one of the biggest factors when the air just looks dirty — and nitrogen dioxide are considered harmful to health and the environment by the Environmental Protection Agency.

Seattle has seen similar drops due to stay-at-home orders.