For a place devoted to personal hygiene, the bathroom can get plenty unsanitary. From hair in the sink to toothpaste smeared on the counter, the aftermath of our grooming is often ugly. Because cleaning the bathroom isn't exactly enjoyable, it can easily get kicked down the to-do list. Showers do get cleaned relatively often according to a survey released in 2023, but there's a lot more involved in scrubbing down the bathroom.
Letting germs linger can prove harmful. Even spotless bathrooms can facilitate the transmission of illness, and irregular cleaning could elevate those risks. With these concerns in mind, we swabbed a range of surfaces in three home bathrooms to test for the presence of potentially harmful microbes. We also surveyed over 500 people about their bathroom habits to learn what might contribute to this bacterial count.
To learn how many germs could be calling your bathroom home, keep reading.
Toilets may seem particularly repugnant, but they don't even come close to the shower in terms of germ concentration. In fact, our swab results revealed astronomically high bacterial counts from two shower components: the curtain and floor. Most people are familiar with warnings about fungi or bacteria lurking in public showers, but our findings make shower shoes seem like a prudent precaution in one's own home. It's not entirely surprising that germs thrive in a wet environment, however: Moisture is a prerequisite for bacterial survival and growth. Which other bathroom surfaces provided germs a happy home?
Recent studies have found alarming substances nestled within toothbrush bristles – including fecal matter that apparently wafts through the air once we flush. But our findings suggest the toothbrush handle may be where bacteria truly flourish, with more than 12.6 million colony-forming units (CFU). Although the handle never exactly enters our mouths as we brush, it doesn't get rinsed off after every use, either. Plus, toothbrush handles enjoy extended contact with our hands, which are prime bacterial real estate in their own right. By some scientific estimates, each human hand is home to roughly 150 species of bacteria.
Interestingly, though, other surfaces we touch frequently had relatively few bacteria. The faucet and interior door handles had only a fraction of the bacteria found on the shower curtain or floor. That doesn't mean you can throw caution to the wind with regard to these surfaces, however – especially when you're in a public restroom. Experts still advise using the paper-towel-to-turn-off-the-faucet trick and doing the same with the interior door handle as you exit.
Although you probably aren't thrilled about any bacteria residing in your bathroom, some varieties are completely harmless to humans or even helpful in certain cases. Gram-positive rods, for example, are typically innocuous; this type of germ dominated surfaces such as the faucet handle. Bacteria of the bacillus variety had a more mixed record: Although they can cause illness, they may also help in the human digestive process. This bacteria was relatively rare in our bathroom swabs except on a single surface: It represented nearly three-quarters of the germs found on toilet seats.
Unfortunately, more harmful bacteria also had a sizeable presence. Gram-positive cocci, which are associated with skin infections and several other illnesses, represented nearly 15 percent of germs found on the interior door handle. But gram-negative rods, which are pathogenic in the vast majority of cases, represented the greatest threat. They were the predominant bacteria on our three germiest surfaces and the most common variety of bathroom bacteria overall. Because they are sometimes resistant to drugs, these bacteria are of great concern in hospitals, let alone in the average home.
Which habits might produce the bacteria counts we observed on each surface? When we asked individuals about their own bathroom behaviors, a few possible explanations emerged. Most men and women, for example, admitted to peeing in the shower, although some experts suggest doing so is relatively sanitary (and even a valuable way to save water). Similarly, 61 percent of respondents reported having sex in their showers, although it's unclear doing so produces more bacteria than taking a shower solo. Plenty of people also combined rinsing off with other grooming activities, including 65 percent who shaved in the shower.
Whatever you do within the confines of your bathroom, it will likely require consistent cleaning. In this regard, women were more reliable, cleaning their lavatories four times a month on average. This finding resonates with recent data suggesting women still do more than their fair share of housework. But even if we clean regularly, we may delay in making more significant improvements. More than half of respondents saw mold on their shower curtain, a situation doctors urge homeowners to address promptly.
Our findings suggest our bathrooms are likely rife with bacteria, but we certainly can't avoid these germs altogether. The obvious solution is more frequent and effective cleaning, and in this regard, there's no substitute for good old-fashioned elbow grease. There are some techniques, however, that might help inconsistent cleaners adopt a new approach to bathroom sanitation.
If you tackle your bathroom only when grime gets unbearable, creating a fixed cleaning schedule is a solid first step. Although scrubbing your toilet weekly probably sounds like a drag, cleaning feels much more manageable when it's done regularly. Plus, you can take your chores with a side of leisure: Fire up some tunes or a great podcast, and watch the time fly by.
Last but not least, strategize with your family members about splitting up cleaning duties fairly. Shared germs can make everyone ill, so keeping things clean should also be a collective effort.
We performed a surface culture analysis of three home bathrooms. Two were in homes occupied by women, and one was in a home occupied by a man. We also ran a survey of 504 people. Our survey consisted of 274 women and 230 men, with an average age of 37.
You're welcome to share this content with your own audience for noncommercial purposes – especially if someone you know needs a little extra incentive to great scrubbing. We simply ask that you cite our research so that our team gets proper credit for this project.