Wednesday, August 12, 2009

You know that antibacterial soap you use?

It's winding up in the environment.
Triclosan, an antibacterial chemical found in everyday bathroom and kitchen products, is accumulating in dolphins at concentrations known to disrupt the growth and development of other animals.
Whatever happened to good, old fashioned soap? Ivory Soap folks. Ivory Soap.

So how does it work (in disrupting development)?
Triclosan is strikingly similar to thyroid hormone, so it might bind to hormone receptors, said Helbing, author of the frog study. Because frog and mammal endocrine systems are similar, triclosan can potentially “affect how hormones work in ways that aren’t intended” in dolphins, and maybe even humans, she said. Altering thyroid function in humans and animals might cause abnormal brain development and other developmental defects.


Ivan Privaci said...

To add to the issue - last time I poked around on pubmed to check, it looked like triclosan was actually pretty lousy as an "antibacterial" (My impression is that it's moderately effective against Staphylococcus species and a few other members of the Firmicutes, but on the whole doesn't really bother most bacteria much.)

So, not only does it build up in the environment, but it doesn't look like it even does a good job when it comes to the excuse for sticking it in the soap in the first place...

Thomas Joseph said...

Come to find out, not only is it in soap but they put it into clothes as well. I've heard of these "antibacterial clothes" (socks, shirts, etc) but they seem silly. I always pass over them.

The other question is ... does subclinical doses of triclosan promote antibacterial resistance to clinically-employed antibiotics?

There is some evidence that this may be happening.

This review (which I do not have access to at the moment) suggests that the literature does indeed point this way. DOI: 10.1089/mdr.2006.12.83

Genomic Repairman said...

Man what the heck just happened to good ole fashion soap. Its cheaper, less harmful, and you don't feel like a rube for buying it.

microbiologist xx said...

I think these people lose site of the fact that bacteria are already everywhere and that the overwhelming majority are completely harmless.
The only garment I can think of that might benefit from being antibacterial is a hazmat suit. Anything else is overkill.
Yes, soap, warm water, bleach...all work effectively against most bacteria. If they didn't, we'd be in big trouble. Hell, the dishwasher is a great sanitizer and often overlooked. It's a much better option than making every dish antibacterial.

Thomas Joseph said...

MXX: You are spot on. People DO lose site of the fact that bacteria are everywhere. People seem shocked, SHOCKED, when I tell them that their food supply is not sterile. NOT STERILE. Everything you buy, everything you consume -- unless it specifically says it is sterile (and find me a significant amount of those food stuffs) -- will contain bacteria on it.

From a food safety aspect, the food on your table is there because it has been checked for certain levels of contaminating organisms. If they're not recalled all you know is that harmful, pathogenic organisms, are not found at levels which will make people sick. Of course there are the organisms for which we have a zero tolerance policy, such as Listeria monocytogenes for which even a single colony results in that item being removed immediately from the food supply, but not all organisms are treated that way. If they all were, we'd have to switch to a pill for all our nutritional needs.

soil mama said...

I think this is a place where science education (or lack of) really comes in. If people knew that bacteria were everywhere and most were either harmless or even helpful, then maybe they wouldn't feel the need to use antibacterial everything.

When I was taking microbiology in undergrad, the prof pointed out that with billions of bacteria on a surface, does it really matter if you kill 99.9% of them? Most people just can’t even comprehend these orders of magnitude.

It seems like at some point the government will need to step in and just ban the products, or run a massive campaign to dispel the notion that antibacterial products are a good thing…

Ivan Privaci said...

I was under the impression that the "antibacterial" socks etc. involved the use of silver in the threads rather than triclosan. Why the heck would anyone buy "antibacterial" clothes with an antibacterial agent that will get washed out when you launder them?
(And I write that knowing, cynic that I am, that lots of people would, and would walk around for months convinced that the no-longer-antibacterial clothing items were somehow "protecting" them...and therefore it doesn't surprise me that someone might make such a useless product.)