Southern Californians who venture outside this week will see excellent air quality, resulting from business closures during the coronavirus pandemic and recent rain.

The area’s famous freeways are empty but experts say the lack of cars is contributing only a small amount to the clear skies, the San Gabriel Valley Tribune reported.

Shipping is down in the ports, meaning fewer trucks and cargo vessels are running.

There are also fewer planes flying and more construction projects on hold. Emissions from heavy machinery accounts for nearly 80% of all greenhouse gas emissions in Los Angeles County.

Researchers are analyzing just how much emissions have dropped and results are expected in a few weeks.

Satellite images of the United States, China and Italy have shown a decline in pollution during the first weeks of March.

In the U.S., there was noticeably less less nitrogen dioxide over California after the governor ordered residents to stay at home. The pollutant comes primarily from the burning of fuel.

The Environmental Protection Agency on Thursday abruptly waived enforcement on a range of legally mandated public health and environmental protections, saying industries could have trouble complying with them during the coronavirus pandemic.

The oil and gas industry were among the industries that had sought an advance relaxation of environmental and public health enforcement during the outbreak, citing potential staffing problems. The EPA’s decision was sweeping, forgoing fines or other civil penalties for companies that failed to monitor, report or meet some other requirements for releasing hazardous pollutants.