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Do saltwater and sunshine at the Shore kill the coronavirus? Here’s what science says.

A deserted beach is a symbol of solitude and natural beauty. Now, having no one else around may be only way to safely enjoy the shore.

A woman carries an umbrella across the beach in Wildwood, N.J., on July 3.
A woman carries an umbrella across the beach in Wildwood, N.J., on July 3.Read moreTIM TAI / Staff Photographer

If you’re debating whether it’s safe to go to the New Jersey Shore, you have company. Scientists are also uncertain.

The coronavirus emerged in China barely five months ago, too recently to know for sure how it responds to baking sun, ocean breezes, salty swells, and humidity.

Nonetheless, there are some clues.

The great outdoors

Coronavirus infections appear to spread far more easily in closed indoor environments than outdoors. Chinese researchers traced 318 outbreaks of three or more cases and found all were linked to indoor transmission; the only outdoor transmission involved two cases. Japanese researchers found the odds of indoor transmission were about 19 times greater than in the open air.

“Most buildings are not well ventilated,” said Dylan H. Morris, a Princeton University researcher who is studying factors that affect coronavirus transmission. “If you happen to be in the same place as a sick person, it’s better to be outdoors.”

» READ MORE: Can I go to the beach? What you need to know before you even think about heading down the Shore.

Summertime, summertime

The impact of seasonal heat and humidity is hotly debated and coldly calculated. Will coronavirus infections ebb in the summer like the flu, or will the new virus keep ripping through communities because of our lack of immunity to it?

The White House recently touted lab studies done by the Homeland Security Department that found increases in temperature, humidity, and ultraviolet light — responsible for summer tans — can accelerate the natural decay of virus particles on various surfaces. At a news briefing, a top Homeland Security official said, “The virus in droplets of saliva survives best in indoor and dry conditions.... The virus dies quickest in the presence of direct sunlight.”

Other experts say sultry summer weather may reduce coronavirus activity, but not by much. Massachusetts Institute of Technology researchers analyzed the spread of the virus and local weather conditions through March in countries around the world. They speculated that nations with high humidity in the form of monsoons “could see a slowdown in transmission,” but “it is extremely unlikely that the spread would slow down in the USA or Europe.”

Surf’s up

Gargling with saltwater may soothe a sore throat, but it won’t prevent the coronavirus from entering your lungs, says a myth-busting post by Harvard University’s School of Public Health. A logical corollary is that accidentally inhaling or slurping a bit of ocean water won’t do anything to ward off coronavirus infection.

On the other hand, at least one prominent scientist is worried that ocean water may promote coronavirus infection, a scenario for which there is no evidence. Kimberly Prather, an atmospheric chemist at Scripps Institution of Oceanography in San Diego, told the Los Angeles Times the virus could enter coastal waters, just like the germs that are washed from roads and sewers by heavy rain. Then waves could spray coronavirus-laden droplets that swimmers or surfers could inhale.

“I wouldn’t go in the water if you paid me $1 million right now,” Prather told the newspaper.

Kay D. Bidle, a marine biologist and oceanographer at Rutgers University, told that he has suspended his own surfing hobby to play it safe. But he also said scientists don’t know how the coronavirus behaves in salt water or how abundant it is in the ocean. “We have no idea,” he added, “whether it’s making its way into the ocean.”

» READ MORE: Can I go camping in Pennsylvania during the coronavirus?

Risks, but also benefits

Even at the beach, basic precautions against COVID-19 — a face mask and staying at least six feet apart — may be required. For some people, that could turn a fun summer pastime into yet another pandemic punishment.

One thing is clear: many studies have found that spending time communing with nature has physical and mental benefits. That’s why some experts, including Harvard University’s Marc Lipsitch, have argued in favor of keeping parks and beaches open.

“There is still uncertainty, so caution is warranted,” said Morris, of Princeton. “But for people’s mental health, and to help them handle this tough crisis, it’s important that they continue to have sources of joy in their lives.”