It can feel as though you’re running an infectious gantlet when using a public bathroom, especially following last week’s news of toilet plume, that cloud of aerosol droplets that can rise nearly three feet and linger long enough to be inhaled by the toilet’s next user, or land on other surfaces of the bathroom. And, in a way, you are.
So what to do, especially now that many of us are starting to leave home a little more? Should we avoid shared restrooms — in parks, malls or recently reopened restaurants — like, well, the plague?
As an obstetrician and gynecologist, I spend a lot of time dispelling the myth that you can catch a sexually transmitted infection from a shared toilet seat (because you can’t, not even herpes, which is the most commonly believed myth). But what about the coronavirus?
First, how infectious are bathrooms, really?
We know they can be infectious by touch. We wipe and potentially contaminate everything we touch with infections that come from stool, like norovirus and E. coli, before our hands get washed.
Bathrooms can also be infectious by air. With some respiratory viruses, like influenza, if enough infectious particles are airborne, breathing a previously shared airspace can pose a hazard. The best example is measles. If someone with measles enters a room, the air is potentially infectious for two hours.
Bathrooms have another unique hazard: toilet plume. With each flush, the toilet releases an invisible army of microbes into the environment, where they land on walls (which you may touch while hovering over the seat — more on that later), the toilet seat, the floor and the toilet and door handles.
We’ve known about toilet plume for some time. A new study suggests potentially infectious particles continue to be airborne for about a minute after each flush, and toilets can continue to generate an infectious plume several flushes after the original contaminated flush.
It’s truly the unwelcome gift that keeps on giving.
So what about the coronavirus?
In general, contact with contaminated surfaces is not believed to be a primary method of coronavirus infection, but this is still understudied. While shared bathrooms can increase the spread of gastrointestinal infections, we don’t know how bathrooms play a role in transmission of a respiratory virus, like the coronavirus, that has also been identified in stool.
We also don’t know the risk — if any — posed by coronavirus aerosols in the toilet plume, so admittedly there are a lot of unknowns.
What we do know is that there are certain bathroom behaviors that will help protect you from many nefarious microbes.
Here’s a handy checklist for shared bathroom use.
The best defenses against bathroom contagions are a mask, social distancing, limiting the surfaces you touch with your hands and hand hygiene.
Consider larger bathrooms with multiple stalls because they have more air circulation.
If someone exits a bathroom stall or a single bathroom right before you, try waiting at least 60 seconds before entering — especially if the toilet seat lid is up, signifying more plume.
Skip the paper toilet seat covers. They are likely placebo — we have no idea if they offer protection from bacteria or viruses — and they could easily be contaminated with toilet plume, so touching them with your hands could be a source of infectious transmission. (They are largely absent in other countries — we never had them in Canada, where I grew up, and when I moved to the United States they seemed so prudish.)
If you need to dispose of a menstrual product in one of those little containers, touch the lid with a wad of toilet paper and sanitize your hands after. Those lids are among the worst surfaces in the bathroom stall: touched by many unwashed hands and showered with infectious plume.
If the toilet has a lid, close it (with toilet paper) before you flush so it traps the plume. Think of the lid as a mask for the toilet.
If an automated toilet is flushing, step back because those things spray.
How you dry your hands after washing probably doesn’t matter — paper towels or dryers are likely equal. But do avoid shared, reusable hand towels.
Get out of there quickly. Chatting in bathrooms is the new smoking in bathrooms — it’s a relic of the past. If you have to open a door to exit, use hand sanitizer after you leave.
But what if you can’t find a bathroom or the one you find is gross?
First, try to avoid needing a bathroom. If you’re heading out, modify your water intake. Remember, eight glasses of water a day is a myth.
For women, you can try squeezing and relaxing your pelvic floor muscles very quickly (each contraction and relaxation should take one to two seconds) five times. These are called quick flicks and will relax the bladder, suppressing the urge. This may buy you some time.
Going to the bathroom outdoors should be a last resort. If everyone starts using the outdoors as an outhouse, the smell of urine will be intolerable and people will get sick unnecessarily because appropriate sanitation is vital in containing many infectious diseases.
If you are caught outdoors with no other option but the ground, try to get 200 feet away from foot traffic — and beware of plants like poison ivy! Use hand sanitizer when you’re done afterward.
And what about, God help us, the airplane bathroom?
Airplane bathrooms are some of the worst. On a long flight, they may go a long time without cleaning; they’re also cramped and the turbulence may lead to water or urine spray.
Sometimes you don’t even have to use an airplane bathroom to be exposed to the germs you would find in one. In one study, passengers sitting in the aisle seat may have been infected by an unwell passenger as they made their way down the aisle to the bathroom and back.
We don’t know the risk of catching Covid-19 after entering a small airplane bathroom right after someone who is infected with the coronavirus, but, as I mentioned above, you should wait to enter a bathroom that someone has just exited — especially if the toilet seat is up — and then get out fast.
The airplane industry likes to say its bathrooms are as clean as those in any office building (data partly funded by the industry). And they are probably as clean as any bathroom with a facility-to-user ratio of between 1:50 and 1:75, and where the bathroom and sink are in a small closet exposed to turbulence and cleaned every four to 18 hours.
And please, have a seat (or raise it).
I have one final request, particularly of women (up to 85 percent of whom report avoiding this): Please sit down. Sitting directly on the toilet seat isn’t going to put you at risk for an S.T.I., so don’t hover. This often leaves urine on the seat, which means you or the next person has to wipe the toilet seat — the surface with the most exposure to the infectious plume — before sitting. This also goes for those who stand: Please raise the seat.
Here’s a golden rule for shared bathroom etiquette now and always: Think not just of yourself, but of the seven or so people who will be using it after you.
Dr. Jen Gunter is an obstetrician and gynecologist practicing in California. She writes The Cycle, a column on women’s health that appears regularly in Styles. She is also the author of “The Vagina Bible.”