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'Zombie' Hormone Disruptors Rise From the Dead
ananyo writes "Hormone-disrupting chemicals may be far more prevalent in lakes and rivers than previously thought. Environmental scientists have discovered that although these compounds are often broken down by sunlight, they can regenerate at night, returning to life like zombies (abstract). Endocrine disruptors — pollutants that unbalance hormone systems — are known to harm fish, and there is growing evidence linking them to health problems in humans, including infertility and various cancers 'Risk assessments have been built on the basis that light exposure is enough to break down these products,' adds Laura Vandenberg, an endocrinologist at the University of Massachusetts in Amherst who was not involved in the study. 'This work undermines that idea completely.'"
I assume that there simply weren't as many endocrine disruptors in the wild, so it was less of an issue over evolutionary time; but for (modestly complex) chemicals to be photosensitive enough to degrade; but suitably structurally favored to have more than a remote probability of being created by the recombination of their breakdown products is rather interesting...
Would it be in any way adaptive for hormones themselves(which disruptors are often very similar to, hence the ability to neatly disrupt the endocrine system) to have this level of durability, or is it much more likely that it's mere chance, biologically irrelevant until we started pumping the things out on an industrial scale?
Chemicals are your friends. Untested chemicals are your untested friends.
Anyone else getting tired of zombies? They're starting to appear in bad corporate cell-phone ads now.
It was cute for awhile, but there seem to be people taking it seriously enough that they're changing their lifestyles based on the idea. It's silly.
Do not look into laser with remaining eye.
There a lot of serious problems with doing risk assessment for endocrine disruptors.
The first is that there is no known mechanism for most of the effects reported in the literature. Without this mechanism a real science based approach is impossible.
The second issue (and a general problem for that matter) is that many of the studies reported turn out not to be reproducible.
The following articles give some insight into this, relative to BPA which has been (possibly without justification a cause celebre):
http://munews.missouri.edu/news-releases/2013/0102-previous-studies-on-toxic-effects-of-bpa-couldn%E2%80%99t-be-reproduced-says-mu-research-team/
http://www.ncbi.nlm.nih.gov/pubmed/21438738
True, though it wouldn't be rocket surgery (and I'd hope they would already have done so) to establish 'baseline' values by looking at water without known inputs from agricultural or industrial sources, and comparing those baselines with ones that do. Shoddy work gets done in science, as anywhere; but 'negative controls' aren't exactly an alien concept.
Expecting "none at all naturally" is not realistic. OTOH, having lots more of the chemicals, whether combined or not, in the streams and lakes is a problem iof they are endocrine disruptors.
;-)
It's like global warming. We need carbon dioxide. But too much of a good thing is too much.
I find it interesting that the default assumption of everyone looking at chemicals is that they break down and then never recombine.
Unlike trees in a forest, chemicals apparently combine whether anyone is watching or not. (It's too hard to see at night
I like L4D and Resident Evil as much as the next person but this is an article about growth hormones, the cattle industry and how the byproducts don't dissipate as once believed. I guess if you want hits, just add the word zombie to a page.
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In all seriousness though, this is something that demands further investigation. Going skinny dipping, only for her to later turn over and say "no, I've got a headache" is a PITA at best.
I can think of two really simple solutions right off the top of my head. Pour lots of bleach in the water, or place bright full-spectrum lights around the lake to shine all night. Duh!
Better known as 318230.
Kind of makes you wonder if the breakdown products from this stuff can get into your body separately, and then combine there. Well, it makes me wonder. Maybe that's because I'm not a biologist, or maybe it's because I'm a pessimist.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Well here is what gets me... if they break down in sunlight, but then recombine without the light, well.... natural bodies of water tend not to be terribly clear. You don't have to go down far to not find all that much light, especially if the area itself isn't in direct sunlight....
So its likely that in many place, it doesn't even take "night", breakdown is likely only happening within a short distance of the surface.
"I opened my eyes, and everything went dark again"
Just like with pesticides that are known to wipe out bees, nothing will be done about this problem either. The corporate lobbyists own too many of your politicians.
Except of course that the pesticides in question are not "known to wipe out bees." There are (recent) studies that suggest that they may contribute to Colony Collapse Disorder (something for which science has an alternate, proven, explanation, but which is serious enough to warrant continued examination of all potential causes). Does this mean they are safe to continue using without a care? No. What it does mean is that any use of them should be done with caution. The information I have seen is that these new findings about the pesticides in question suggest that commercial beekeepers should change some of their techniques (having to do with the way they get their hives ready for the first flowers of spring). There are further implications for how the pesticides are used, but the information about how the use should change is still sketchy.
The truth is that all men having power ought to be mistrusted. James Madison
If we are going to worry about pollution and it's effects on our wellbeing, let's look hard at this right now.
Of course this isn't politically correct today. Global warming "prevention" fosters a totalitarian state. Flooding the drinking water with estrogen from the massive use of birth control pills might be a problem but that can't be mentioned without being labeled a misogynist.
Peace is easy to achieve, just surrender. Liberty is much harder get/keep.
Birth control is a tiny fragment of the endocrine disruptors that are being dumped out there and estrogen is a chemical that's already present due to many natural processes. Hormones (Testosterone for older men, hormone replacement for older women, anti-depressants all hugely used by the US at least), are also only a small fraction of the problem. Agriculture causes all sorts of crap specifically designed to screw up wildlife that would otherwise attack crops, or to create the mutant animals that are so very tasty. Manufacturing waste...So yeah, it'd be kinda misogynistic to say that world's problems come from some women who want to regulate their cycles.
I'm not saying I'm innocent of all this stuff either; I don't only buy food from local farmers who are contaminating local run-off, I grow my own, and I love mutant cow meat, and most of my friends and family and pets are on some sort of environmentally unfriendly medications.
It clearly isn't a safe default assumption (since it was wrong in this case); but biochemistry is loaded with "Oh, yeah, this molecule is a pain in the ass to synthesize, unless you have this totally elegant catalytic protein, as organisms that use it do" and has fewer well known examples of 'Eh, breaks down under UV; but it'll be fine once the radiation stops'.
There are chemical equilibria designed explicitly for that purpose (self-darkening sunglasses contain one such, whose UV-exposure product is blackish and whose default product is transparent); but it is a bit of a surprise to see a biologically active molecule doing it.
Being concerned with endocrine disruptors has no 'political correctness' problem. Hell, being worried about bisphenol A was practically a lifestyle choice just recently. Now, if you think that your primary problem is hormonal contraceptives, you might have an accuracy problem; but there are broad swaths of commonly used chemicals that make endocrinologists nervous. They tend to have influential users who really appreciate the shareholder value of being able to just dump them in the nearest waterway, so good luck with any progress in the area; but it isn't hard to find science types who will back you up.