The coronavirus may be able to linger in the air for at least half an hour, last for days on some surfaces, and travel almost 15 feet, a new study has found.

The research by Chinese government epidemiologists challenges the advice of health authorities who have suggested staying a “safe distance” of between 3 and 6 feet apart in public spaces to avoid catching COVID-19, according to the South China Morning Post.

“It can be confirmed that in a closed environment with air-conditioning, the transmission distance of the new coronavirus will exceed the commonly recognized safe distance,” the researchers wrote in a paper published in peer-reviewed Chinese journal Practical Preventive Medicine last Friday, per the newspaper.

The researchers from the Hunan province say they found the virus could last for days on a surface, depending on the environment. For example, at 98 degrees, they found it can last two to three days on glass, fabric, metal, plastic or paper.

It can also survive more than five days in human feces or bodily fluids, they said.

The scientists based their findings on a Jan. 22 case of a person with the virus who took a long-distance 48-seater bus ride — and ended up infecting 13 people total, according to the SCMP.

Surveillance footage showed that the patient didn’t interact with others throughout the four-hour ride — but a couple of the people who became infected were sitting as far as six rows away, or about 15 feet, the researchers said.

One person who caught the virus hopped on the bus about 30 minutes after the passenger and the others who became infected had got off — possibly having inhaled tiny particles breathed out by the first group, the researchers said.

The initial carrier then got on another bus, where the virus jumped to two others, also sitting about 15 feet away, they said.

“The possible reason is that in a completely enclosed space, the airflow is mainly driven by the hot air generated by the air conditioning. The rise of the hot air can transport the virus-laden droplets to a greater distance,” said the paper.

The scientists said their research highlighted the importance of wearing face masks — since none of the passengers in both buses who were wearing masks became infected.

“When riding on more closed public transportation such as subways, cars, planes, etc, you should wear a mask all the time, and at the same time, minimize the contact between your hands and public areas, and avoid touching your face before cleaning,” they advised, per the SCMP.

They also suggested improving sanitation on public transportation — including cleaning interiors once or twice a day — and adjusting air conditioning to make sure as much fresh air as possible is coming in.

Still, they weren’t able to answer why passengers sitting immediately next to the carrier — who suffered the highest exposure — were not infected.

“Our knowledge about this virus’s transmission is still limited,” one of the researchers said.