A disturbing trend – casual and reckless use of antimicrobial agents in building materials.

There was a very interesting artilce in the New York Times on August 21 bu Michael Kimmelman: In Redesigned Room, Hospital Patients May Feel Better Already.  The article focuses on a move by the University Medical Center of Princeton to redesign hospital rooms.  And Kimmelman discusses a variety of issues associated with hospital design.

And there were a few aspects of the re-design that relate specifically to microbes.  One makes a lot of sense to me – the positioning of a sink “in plain sight, so nurses and doctors will be sure to wash their hands, and patients can watch them do so”.  It is critical that we as a society work to make sure that hospital personnel and visitors and patients wash their hands more often (and better) than they do now.  

But then there was another microbe-related design issue that I find disturbing.  This issue is from the following paragraph:

While smart design can reduce the chance of such errors, nobody claims that buildings cure disease. But how much each or any of the design moves in the University Medical Center of Princeton contributed to reducing pain or improving patient approval ratings is also not clear, which frustrates Barry S. Rabner, the hospital’s chief executive. He gave the example of antibacterial flooring, which cost $1 per square foot more than equivalent flooring without the antibacterial agent. “Sounds like a good idea,” he said. “So we did it. But that’s around a $700,000 difference. And where’s the evidence that it works?”

Wow.  So they put in flooring that apparently was impregnated with some sort of antibacterial agent and they have no evidence that it works.  This bothers me because it seems entirely possible that this would have negative, rather than positive, consequences.  Mind you, I do not know if there are negative consequences of using antibacterial flooring but it is not too far fetched to imagine this is possible.  There is growing concern about overuse of antimicrobial agents in many areas including medicine (e.g., see here), agriculture (e.g., see here), hand soaps, kitchen cleaners, and more.  What is the problem with overuse of antimicrobials?  Well, in general, there are two main issues people worry about – the evolution and spread of antimicrobial resistance and ecological disturbances to communities which in turn can have many negative consequences.

Sure – I am certainly in favor of keeping operating rooms as clean as possible.  And I am certainly supportive of getting everyone involved in helathcare to clean their hands more often and not serve as vectors for movement of microbes in and around hospitals.  But putting antimicrobial agents in hospital flooring – especially in patient rooms (as opposed to operating rooms) – seems to completely fail the precautionary principle.

Alas this impregnating of building materials with antimicrobials is not just happening at this Princeton hospital.  It is a growing trend.  As with hospitals, this makes sense in some situations such as drug and food production facilities.  But it scares me in other settings such as car seatsdrywall coatings, clothing (also see here), shoes, and so on.  Of course, I am not saying the microbial world out there is always in our favor.  There are certainly microbes that can harm in all sorts of places.  But it seems likely that there could be long and short term damage done by this “kill the germs” mentality applied to the whole planet.  This is of course related to the absurd levels of germophobia we see in society today (see Katie Dahlhausen’s post on 50 shades of gross for a litany of examples).  To protect ourselves (i.e., humans) and the plants and animals we care about as well as the planet, we need to have a more rational and careful approach to microbes.  They can be good sometimes.  They can be bad sometimes.  They can be lots of things.  But reckless and mindless attempts to kill all the microbes around us almost certainly will come back to haunt us.


11 thoughts on “A disturbing trend – casual and reckless use of antimicrobial agents in building materials.

  1. Interesting point. Certainly in regards to the flooring it makes little sense in the absence of some evidence, but there are some common sense opportunities as well. What about the use of surfaces that are not impregnated with traditional antibiotics, but, nonetheless have antimicrobial properties. I am thinking about copper. Doesn’t it make sense to keep surfaces that are commonly touched by patients and hospital staff, like doorknobs, IV stands, and bed rails, free of bacteria if it will not lead to resistance? One would imagine that such steps could be quite effective in ICUs.

    1. I am not sure copper is any better than any other antimicrobial. What do you mean by “does not lead to resistance?” Also – resistance is not the only issue. Antimicrobials also disturb the ecology of a microbial system. Such disturbances are known to cause significant problems – consider for example C. difficile infections that come after antibiotic usage. So coating every surface with copper will likely also disturb the mcirobial ecosystems. In an operating room, or drug production facility, I think this is probably an OK idea (though I would like to see evidence). But in a patient room where someone might need to recover from surgery or a heart attack or a car accident? I am not sure what would be best there. Perhaps it would be best to try and foster a beneficial / non dangerous microbial community. Putting copper everywhere could potentially have the same effect as putting triclosan everywhere.

  2. doing all this is so counter productive it defiers belief
    with a major problem with me /mcs fm patients being smells chemicals etc
    you put the cleaning -hygiene smells in the same room
    please tell me your just joking

  3. Another reason to be cautious: Adverse health effects associated with human exposure to the microbial agents. Several chemical elements and compounds that have been used as antimicrobials were later deemed unhealthful. Among these: mercury applied as a fungicide in paints used in bathrooms and other high humidity environments; pentachlorophenol applied as a wood preservative; and triclosan in many personal care products. When used in buildings, there are ample opportunities for human exposure including routes such as volatilization followed by inhalation intake or transdermal permeation.

    I’d be curious to know what chemical or chemicals provide the antibacterial properties of the flooring. A quick google search shows products that use photocatalytic TiO2 (not clearly beneficial indoors owing to the low UV lighting level), silver nanoparticles, and an organotin, tri-n-butyltin maleate.

    For some further discussion of these issues, see N Carslaw et al., Chemical versus biological contamination indoors: trade-offs versus win-win opportunities for improving indoor air quality, Indoor Air 23, 173, 2013.

    1. I would be curious about this too although I note there are some people claiming that some surfaces can be antimicrobial due to form rather than chemistry but I have not seen much on these.

  4. Spending an extra Dollar per square foot is hardly a casual act in today’s healthcare facility construction “industry.”

    Nevertheless, Nazaroff makes an important point in his comment.

    Our history of the use of biocides reflects the “innocent-until-proven-guilty” approach in the regulation of commercial products in America. The history of termiticides is a great illustration — a chain of products were in widespread commerce before their adverse effects were sufficiently documented to warrant regulation, or, more precisely, changes in their registration. EPA “registers” pesticides based on evidence that the do what their manufacturers claim they without regard to potential harm. Only when harm is shown is the registration re-considered and revised to limit uses and, presumably, harm to humans, other living things and the environment more generally. We went from Pentachlorophenol, ubuquitous in the consumer products and the environment and the favored wood preservative (Environment International Volume 12, Issues 1–4, 1986, Pages 333–341; http://www.buildingecology.net/index_files/publications/GenPopExpToPenta.pdf) and termiticide, to chlordane, and chlorpyrifos successively in a brief period of only a couple of decades. Human health harm was shown in all three cases leading to EPA restrictions on use or withdrawal from the market.

    “High end” ceramic products with antimicrobial properties are marketed for use indoors (including as flooring) and for use in healthcare as well as many other environments (e.g., residential and commercial kitchens, bathrooms, among others). To see an example of such marketing with lots of details on uses and the antimicrobial action, see http://casalgrandepadana.com/index.cfm/3,224,2682/bios_ceramics.pdf. It is a dual language (Italian and English) publication with lots of information and illustrations of potential interest to visitors to the microbe.net site. The document contains some nice illustrations of four of the most common infectious agents found in healthcare settings. What the document does not address is the “hygiene hypothesis” or the ideas reflected in yesterday’s post on this site about a NYT article featuring a new hospital with, among other features, antimicrobial flooring – http://microbe.net/2014/08/24/a-disturbing-trend-casual-and-reckless-use-of-antimicrobial-agents-in-building-materials/.

    What’s puzzling to me is the polarization that is going on around people’s reaction to the so-called “hygiene hypothesis” or the widespread use of antibiotic drugs and antimicrobial products.

    Reactions to Martin Blaser’s recent book, “Missing Microbes,” and the publicity surrounding it illustrate the diversity of views on the subject. (http://us.macmillan.com/missingmicrobes/) It even received the overselling of the week award on the phylogenetics web site – http://phylogenomics.blogspot.com/search?q=overselling.

    1. I think the issue here is hype and fearmongering on all sides. Should we be as germophobic as we are (as a society)? Almost certainly no. But does that mean that every claim about the benefits of germs is also true? Also almost certainly no. What we need is to be cautious (e.g. about overuse of antimicrobials) without overstating their risks or benefits (e.g., my criticisms of Blaser relating to his book and of the press about his book relate to overstating what is known about so called missing microbes).

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Jonathan Eisen

I am an evolutionary biologist and a Professor at U. C. Davis. My lab is in the UC Davis Genome Center and I hold appointments in the Department of Medical Microbiology and Immunology in the School of Medicine and the Department of Evolution and Ecology in the College of Biological Sciences. My research focuses on the origin of novelty (how new processes and functions originate). To study this I focus on sequencing and analyzing genomes of organisms, especially microbes and using phylogenomic analysis (see my lab site here which has more information on lab activities).  In addition to research, I am heavily involved in the Open Access publishing and Open Science movements.