Comment by wahern | Hacker News Reader

Comment by wahern | Hacker News Reader

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Steel is one of the worst surfaces when it comes to harboring pathogens. AFAIU silver and copper are the best. Brass and bronze come in a distant 2nd (in absolute terms) but still significantly better than steel, where pathogens linger subject only to the external environment. See, e.g. https://en.wikipedia.org/wiki/Oligodynamic_effect and https://en.wikipedia.org/wiki/Antimicrobial_properties_of_co... and http://www.academicjournals.org/article/article1380626432_Va...

I wish hospitals, airports, and other shared spaces would use brass hardware or other alternatives rather than steel, particularly on door knobs and other highly trafficked surfaces. I always wondered if there'd be a market for selling such biocidal and viricidal hardware, either passive hardware using special alloys or surfaces (e.g. untreated wood performs well by locking pathogens in pores so they don't transfer readily); or active hardware that, e.g., ran a small current across the surface.

There's a huge number of companies already in this space - the biggest problem is actually showing that they work, rather than just being somewhat nifty materials that work in a lab.

For example, a recent RCT showed that antibacterial-impregnanted scrubs were relatively ineffective in hospitals: https://www.cambridge.org/core/journals/infection-control-an...

Unfortunately this feels like situation where the free market will fail to incentivize the best solution. The airport itself does not feel the economic pain from its travelers getting sick from touching its steel surfaces. The passengers likely aren't even aware this choice might have caused their sickness. So airports will always choose steel over copper/silver/brass so long as steel is cheaper.

This seems like a reasonable place for regulators to step in.

There is no free market, airports are owned and operated by the government. Regulations are not necessary. If the government wants copper fittings, they simply need to order them.

Although the vast majority of major airports are state owned, some aren't. Notably, most major airports in the UK (including Heathrow and Gatwick) are privately owned and operated.

I agree. And perhaps a subsidy. The potential avoidance of misery justifies making it easy to choose.

A regulation and a subsidy are called for because people don't wash their hands often enough?

Or aren't able to.

Airports are a controlled environment where your free will is a lot less meaningful than usual.

I'm quite fond of hand-washing, and I hate airports because they make it so difficult. You have to touch everything, and everything touches you, and sinks are few and far between, and only located in jam-packed restrooms.

You also can't bring decent quantities of hand sanitizer through checkpoints. This ban on liquids and gels applies to alcohol gel, BZK foam, povidone solution, and towelettes premoistened with any of the above. I checked.

Once aboard the plane, there's no effective handwashing. The bathrooms are so small you brush the walls with your shoulders while turning around, the trash-flap has to be shoved on to deposit your paper towel, and the door latch has to be touched to be operated.

After you've arrived at your destination, luggage at the baggage claim has been handled by folks outside your control, who themselves probably don't wash their hands very often, and once you've grabbed it, even if you wipe it down with some towelettes you've squirreled away, there's no restroom nearby to wash the remaining mostly-dead germs off your hands.

So please, tell me which airports you've been flying where handwashing is easy, and I'll try to schedule a connection through one to check it out.

You can wash your hands at any airport in the world. Also, neither you nor anybody else has been on a flight that required more than 100ml of hand sanitiser to keep yourself clean. If you're using more than that, then you have a problem and it's not related to bacteria.

I don’t disagree but I do regret reading this.

Do you suffer from OCD?

You can do none of these things and be just fine.

People routinely get sick when traveling to the point it's basically a trope. Keeping your hands clean is an excellent problem way to reduce your likelihood of getting sick in general.

You, personally, may not get sick traveling, but your experience is not a solution for a systemic problem, nor is your proposal of doing nothing.

It's possible that people who routinely get sick when traveling are the ones that live their lives in self-made sterile cocoons... a tiny sliver of the air-travelling public.

> People routinely get sick when traveling to the point it's basically a trope.

The only version of the trope I've heard of before is eating in foreign 3rd world destinations (eg: Delhi belly). I live in a major tourist destination and if tourists were routinely getting sick out here I'd know about it.

I mean of course one should be washing their hands after using the bathrooom, but all that other stuff you mentioned.. that's anal to the point of obsessive.

>I mean of course one should be washing their hands after using the bathrooom

Isn't a large value of washing after using the restroom that it means you'll wash your hands multiple times a day when you wouldn't otherwise?

> but all that other stuff you mentioned.. that's anal to the point of obsessive.

Arguments similar to this were used against washing your hands at all when we first developed a theory of germs and contamination.

Really though, this discussion won't progress until one of us has supporting data.

Fair enough.

I don't have data to support my conclusions, but I subscribe to the Hygiene Hypothesis... humans have lived in filth for millennia, and our bodies haven't evolved to live in sterile conditions.

https://en.wikipedia.org/wiki/Hygiene_hypothesis

It seems easier and cheaper than forcing everybody to have good hygiene. Maybe the Nazis could make it happen, but I think we'd lose much more than we'd gain.

They found the plastic trays to be the worst.

> Of the surfaces tested, plastic security screening trays appeared to pose the highest potential risk, and handling these is almost inevitable for all embarking passengers.

I've wondered how athelete's foot fungus feels about the remove-your-shoes regulations. What a boon to reproduction!

I hope it works similar to bacteria, where "tile, wood, and laminate surfaces transfer much more bacteria than carpeted surfaces." (https://news.nationalgeographic.com/news/2014/03/140315-five...) Most of the security areas I've seen are carpeted, albeit low pile carpeting.

But maybe it doesn't work the same; or maybe it's just so contaminated it doesn't matter. The best solution[1], though, is probably to sell your soul to the devil and enroll in TSA Precheck.

[1] Presuming there's a real problem. Aren't the fungi that cause atheletes foot (tinea pedis) and onychomycosis (infection of the nail bed) pretty much everywhere already? I think it's more a matter of keeping your [low-temperature] extremities dry. Onychomycosis is almost inevitable past a certain age because of immune and circulatory deficiencies.

I'm pretty sure wood is terrible for this purpose. Note how in hospitals wood is nonexistent.

Plastic and steel are common because they're easy to clean reliably. The problem is that the properties that make them easy to clean--smooth, inert--are the same properties that allow pathogens to linger.

Microsurfaces on, e.g., hardwood have properties that sequester and kill pathogens. (https://news.ncsu.edu/2014/09/cutting-boards-food-safety/) However, that can also make them more difficult to clean, particularly in a commercial or industrial setting where the process needs to be low-cost, minimally labor intensive, scaleable, and reliable. Similarly, the surface properties may be difficult to maintain or restore. For example, perhaps oil build up on wood surfaces regularly touched by passers-by reduces or eliminates the antimicrobial qualities, or even make it worse than the alternatives.

That's the rub--how to design (and market) cheap hardware that is easy to maintain while maximizing antiseptic properties during use. We've optimized for the former (cheap, easy, reliable sanitation) but neglected to appreciate that actual cleanliness sucks because typical materials in high-traffic areas go from pristine to cesspools almost immediately and, crucially, stay that way until the next round of cleaning briefly sanitizes the surface.

It's also got to withstand those disinfectants. My guess is wood likely also degrades faster.

What kills wood is a changing environment. Keep it dry and it lasts forever. Keep is wet and it lasts forever. Let is cycle between wet and dry every hour, it last a week.

It may be absent, but tests on food prep surfaces show wood performs surprisingly well. Better than plastic.

From what I remember, wood's main difference is that is absorbs water. On the one hand, this wicks water away from the surface making it dryer immediately (bad for pathogens), but on the other hand it retains moisture for longer (good for pathogens). These trade-offs are overall beneficial for the use case of a cutting board, but that may be a very narrow set of conditions.

This is aside from the fact that hospitals are a more adversarial environment than kitchens--every sneeze might contain ebola, and every patient might be immunocomprimised. I would imagine airports fall somewhere in the middle.

there are documentaries about that, and at least one hospital was shown using copper handles and knobs in some area.

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