SGU Episode 184

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Introduction

You're listening to the Skeptics' Guide to the Universe, your escape to reality.

S: Hello and welcome to the Skeptics' Guide to the Universe. Today is Wednesday, January 28^th, 2009, and this is your host, Steven Novella, president of the New England Skeptical Society. Joining me tonight are Bob Novella

B: Hey everybody

S: Rebecca Watson

R: Hello everyone

S: Jay Novella

J: Hey guys

S: And Evan Bernstein

E: Hi everyone

This Day in Skepticism (0:32)

E: It was 1986, and I'm sure we all remember exactly where we were at the moment the space shuttle Challenger broke apart after lift-off.

S: That was on the 28^th?

E: That was on the 28^th, yep.

R: Actually, I do not remember where I was.

B: I do

E: I remember exactly where I was

J: Yeah, I do too.

E: It was sophomore year in high-school, er-

R: I was five.

E: -junior in high-school, in my computer lab, and the announcement came on over the intercom and we all ran to a television set to see what was going on. It was- it was one of those seminal moments – for me, certainly. Hit me pretty hard.

S: I think we talked about this actually on the show before. Because I remember us recounting that I was actually at Hopkins at the time, at John Hopkins and I was online to sign a document which was going to go up in the next space shuttle, because the Hopkins was sending up the Hopkins ultra-violet telescope. Which then got, of course, got delayed by a year or two because of the shuttle disaster. Well, we have a great interview with Tim Minchin coming up later in the show, but first, let's get to some news items.

News Items

Mercury in Corn Syrup (1:25)

Washington Post: Study Finds High-Fructose Corn Syrup Contains Mercury

S: This is a study recently published, that shows that high fructose corn syrup is contaminated with mercury. This is a study that was published by the Institute for Agriculture and Trade Policy. And what they did was look at various food items, some off the shelf, and sent them to various labs to test for their mercury content, and they found that about a third of products containing high fructose corn syrup had detectable levels of mercury, and they put out press releases warning about this. I was looking around the internet to see what the chatter was about it, and all of the links I found, just about, were from fairly either credulous or pro-alternative medicine, or flagrant conspiracy-mongering sites that just loved this news for whatever reason.

R: I heard Jeremy Piven almost died from ketchup poisoning.

(laughter)

S: Yeah, right

E: Poor Jeremy

S: It was actually challenging for me to dig up real information. So one thing that the press release didn't talk about was: how much mercury are we talking about?

B: Just because it's detectable, doesn't mean that the quantities involved are significant.

S: Right. But if you go to the website of the Institute for Agriculture and Trade Policy, there you can get the full study with the table that has the actual amounts. And the amounts of mercury are between 30 and 350 parts per trillion. That's trillion with a 'T'. And again, about a third of the products that they tested, the other products had no detectable levels of mercury. Now, it seemed to me to be a lot of fear-mongering around this, and again, I was trying to put this into some kind of context, what does this actually mean? What kind of health risk does this present? And, again, the vast majority of the sites didn't make any attempt to put this into any kind of context. So one thing that's certainly true is that mercury is a toxin, right? That is the thing that is not under debate, nobody's saying that mercury itself is safe, and there is a pretty broad effort to minimise human exposure to mercury. We're all on the same page when it comes to that. But in terms of individual things, and how much of a risk do they present in terms of their mercury content, what I found with this high fructose corn syrup news story was a lot of unsubstantiated fear-mongering, without really digging deep into the details to see what kind of threat this actually presents. So here's a couple of things to put this into context. First of all, the amounts that we're talking about – 30-350 parts per trillion – that is far below what is necessary to cause levels that are considered to be unhealthy, so the EPA and the FDA has their 'safe exposure' levels. One estimate I saw was that you would have to eat 100 pounds of ketchup every day to get to the EPA safety levels.

E: Wow

R: I could do that

(laughter)

S: You could do that? 100 pounds every day? So that's, a lot a lot of ketchup.

R: I could do it on a veggie burger

E: How about (inaudible)

S: Another thing to keep in mind is that there is mercury in the water, and in the soil, and in breast milk, and in lots of things. You could detect this range of level of mercury in lots of stuff

J: Yeah, but is that natural? Is it naturally occurring? How does it get there?

S: In the soil and the air and whatnot?

J: Yeah

S: Well, there's a certain amount of mercury is naturally occurring, and that it just exists in the environment. Certainly, in industrialized parts of the world, a certain amount of the mercury is produced by industrialization, and that's the part we can do something about, and there's been a lot of efforts, by the Environmental Protection Agency and other groups, to do that, to minimise human exposure to mercury through industry. But in terms of the high fructose corn syrup, it seems as if that in the processing of these products, in order to balance the PH, you have to add acids and bases to things in order to balance the PH, that one of these processes included a mercury-based filter, a so-called mercury-cell technology, and it's possible that mercury could contaminate food that was processed this way. So that's what their thinking is, how it got into there. So that would be industrial exposure to mercury, not naturally occurring. However, the industry spokesman have said that that technology was phased out several years ago, and the press release included data from products that were four years old, previous to the mercury-cll technology being replaced by newer technology that has no mercury in it. So-

J: Yeah, but you know, Steve, four years is really not that long of a time. If we were all, on average, consuming 12 teaspoons of high fructose corn syrup a day, up to four years ago, that was a real issue.

S: The point of that, Jay, was that the problem has already largely been fixed.

B: You said that these were mercury filters, Steve?

S: Yeah, mercury-cell technology was used in the processing

B: Yeah, cos Jay, now they're using the arsenic-cell technology, so it means we're ok.

(laughter)

S: So, I mean, Jay, you're right, this was an exposure up until four years ago, but it's an exposure at this level, which seems to be like the background level in our environment, not necessarily enough to exceed these rather generous safety levels. The EPA has a safety buffer of what they will consider a safe exposure level, and this doesn't even get up to that, so it's not clear – here's the bottom line – it's not clear if this level of mercury poses a risk or not, and it probably doesn't, given the low levels that we're talking about here. One thing the study did not do, was detect whether the mercury was ethylmercury or methylmercury. Methylmercury is much more toxic, much more toxic than ethylmercury. If some of the mercury they're producing is ethylmercury, that would reduce the potential toxicity much further than that. However, spokesmen from this group claimed there's still four plants open, one in Georgia, one in Tennessee, Ohio and West Virginia, that are still using the mercury-cell technology. I couldn't find any information to confirm that either way, so it may be that most of the plants have switched over, but there may be a few left over that are still using it. But it sounds like this is something that is already being phased out because, again, just generically trying to limit human exposure to mercury. You know, this is interesting information, but it's nothing that we should panic about, it doesn't mean you have to suddenly worry about what food you're buying off the shelf, these are very low levels we're talking about, probably the data's already old in fact. These attempts at detecting and limiting mercury exposure are legitimate, and should continue, and we should try to have as wide a buffer of safety as possible, but it seems as if the authors of this study, and the group they were representing were going a little bit for the shock value in the press release, which I think overstated the implications of the research.

E: How long before Jenny McCarthy says corn syrup causes autism?

S: Yeah, the mercury militia are already all over this. This is the kind of thing that- 'a big government cover-up of mercury exposure', they love it.

Vaccine Safety and More Outbreaks (9:03)

Science-Based Medicine: More Data on Vaccine Safety Amid New Outbreaks

S: The next news item actually also is about vaccines. I wanted to give a couple of updates about the vaccine controversy that are worth pointing out very quick. So we've spoken a lot in the past about the fact that the dedicated anti-vaccination groups, Jenny McCarthy for example, now is a celebrity leader of this movement, and they claim that the ethylmercury in thimerosol, which is a preservative, in some vaccines caused, or increased the increase of incidence of autism. There's multiple lines of evidence now that shoes that this is not the case. There's growing mountain of evidence, as we say, that this is not the case. There was recently a study published which is one even more evidence against- this is an Italian study, and what they did was very clever. So in 1992 – this is a study comparing two different kinds of pertussis vaccines, one regimen contained a total amount of exposure to ethymercury of 62.5micrograms, and the other, 137.5. And what they figured out was, 'hey, we can go back and look at the kids from this study we did in 1992, because we have two groups that were carefully characterised, and we can go back and see how many in each group got autism, or we could actually do neurological studies on them and see if there's any differences'. So that's what they did. They found out, actually, that there was basically no difference in the two groups in terms of neurological outcomes. They measured 24 different neuropsychological tests, which resulted in over 70 different kind of comparisons that you could make statistically, and of those, four should have been statistically different by chance, and they only found that two were statistically significant. So that is within what we would expect from chance, meaning that there was no difference between these two groups. They also looked at the incidence of autism, and they found there was only one case of autism reported in the whole cohort, and that was in the lower dose group, not the higher dose group. So, more evidence against a link between thimerosol and autism, or any neurological disorder, because this is comparing a relatively high low dose to a relatively low dose. Now, the response of the anti-vaccination crowd and the mercury militia has been predictable. They're going to pick this study apart to deny its implications, and that's what they’ve done. Their main point is that the study did not have a control group of people who got no vaccines, or no mercury, and obviously that would have strengthened the data and implications of this study, but it doesn't take away what the study does show. We have to keep in mind that these are the same people who are claiming that when the vaccine schedule increased in the '90s, so that the total dose of mercury went from around 50 or 60 to around 180, that that caused a dramatic increase in autism. This study is looking at the same order of magnitude of change in exposure to mercury, so they can't say at the same time that it caused this huge increase of autism, but it wouldn't produce a difference in this study, so that's internal inconsistency in their arguments. Toxins should have a dose-response curve, a dose-response effect, where if you more than double the exposure, you should see some increase in toxicity. This study showed none. So of course no one study is going to prove a lack of association, or a lack of correlation, but this adds to the 18 or so studies already out there that show no link between mercury or thimerosol and autism or neurological disorders.

Also, the other quick update is we've talked previously about the fact that since the fear-mongering around vaccines has caused a decrease in compliance, in the UK significantly, to a lesser degree in the United States, and since that's happened, we've been seeing outbreaks of vaccine-preventable diseases occurring in clusters, mostly in un-vaccinated children. Which is no surprise. Last year, in 2008, there have been several measles outbreaks, endemic measles outbreaks, the first time in a decade, again all in un-vaccinated children in areas with low vaccination rates, and now there's a new report of five cases of haemophilus influenza type B, or HIB, meningitis, a very serious illness that can be prevented by vaccines. So there were five cases, three of those children were unvaccinated, and one was a seven month old infant who died. So we talk about the body count attached to Jenny McCarthy's misinformation fear-mongering, and it's starting to pile up more and more significantly as the scare tactics surrounding vaccines is getting more and more play.

E: Scary

S: It is scary.

Evolution Before Our Eyes (14:09)

National Geographic news: Lizards Evolving Rapidly to Survive Deadly Fire Ants

S: So, you guys all know what's happening February 12^th?

E: Um…

J: Yeah, of course!

R: DARWIN DAY!

E: DARWIN DAY!

S: DARWIN DAY! Darwin's 200^th birthday!

E: (singing) Happy birthday-

R: Yay! Oh, but you know, it turns out, he's dead. So…

S: Yeah

(laughter)

E: So we have to spank the corpse 200 times? Is that what you're saying?

(laughter)

S: It's the 150 year anniversary of the publication of 'Origin of Species'. So, leading up to that, we're gonna make sure each week we cover some evolution news item. Last week we gave an update on the creationists' attempts to get intelligent design into schools in Louisiana and Texas.This week, we're going to talk about a very cool, new news item published by National Geographic, in which we can actually see evolution happening before our eyes.

E: Yeah, you know, it's interesting, when you think about evolution, in most people's minds it's something that occurs (speaking slowly) extremely slowly, over many, many millions of years and so forth. (normally) But, there are, of course, cases where it happens, certainly, within the span of a human lifetime. And this again is one of those cases. So what we have here is a species of lizard called the fence lizard, that exist down in the south-eastern parts of the United Stated. And in Alabama, the species survives, but they cohabitate with fire ants, fire ants which were accidentally introduced to the environment in the 1930s, and they like to, well, kill and feast on the lizards, the fence lizards. So what has happened since the 1930s, according to this new study, is that the lizards have undergone an evolution by which they are growing longer legs so that they can shake off the ants when the ants climb onto them. What would happen in the past, is that the lizards would just allow the ants to be there, and they would get under their protective skin and sting them, and it would only take a few stings from a few fire ants to literally kill these things, and then the ants would go and feast on them.

J: Evan, do we know how long that's taken to take place?

E: 50, sorry, about 70 years or so.

J: That's incredible

E: Yeah, just within this span, and most likely less time than that. And what has happened is that the lizards that have the longer legs of the fence lizards were the ones that were able to survive because they were able to just physically shake of these ants more effectively. And the studies are now in that the fence lizards that live in this region, that cohabitate with these fire ants, they are- 80% of these lizards have the longer legs in the region. They compared them to fence lizards in other areas of the south east that don't cohabitate with fire ants, and in those areas, their limbs are extremely smaller. So what we have here is a case of evolution in front of our eyes so that the species can better survive the attack from the ants.

S: What is really interesting about this also, is that they looked at baby lizards, and they found that 100% of them exhibit the behavior of vigorously shaking before running when they get exposed to ants, and they think that that's because their scales are not as well developed, not as thick, so they evolve this adaptation of vigorously shaking so that they dislodge any ants or small critters that are on them, and then running away. But they lose that behavior when they get older, again, the thinking is that they can then rely upon their scales to protect them, so they don't have to waste the time and energy vigorously shaking themselves and running. But now that the fire ants can sting through their scales, those lizards that retain this immature trait of shaking into adulthood, those are the ones that are predominating in terms of the populations in areas where there's fire ants. So this actually isn't an entirely new ability or adaptation, but what it's really showing is the change in gene frequencies in populations of pre-existing traits. In adaptation to selective pressures provided by this new predator in their environment. So this really establishes well the whole bit about natural selection, you know?

J: Heh, the "whole bit"?

S: Yeah

(laughter)

E: The whole thing

S: It's not a new mutation, it's not a completely new adaptation, but it is showing that gene frequencies of traits that vary in a population change in response to selective pressures that we can document being introduced into recorded history in these populations. So again, like any complex scientific process or claim, you can't establish the whole thing with any one piece of evidence or any one study, but this is more evidence for this one piece of evolution, the natural selection bit, and of course, you know that the creationists and the evolution deniers are going to say all the things that this study isn't, missing the point about what this study is. Similar to the vaccine study we just talked about, that's a typical tactic, it's to say what the study doesn't do, or what the data, the evidence doesn't establish, as if that in some way takes away from what it actually does show.

E: You're right, Steve, this just helps compound the existing evidences and reinforces it, of what is already out there. We should also mention that the study was done by Pennsylvania State University, and the lead author's name is Tracy Langkilde.

J: How lucky are we that 70 years ago somebody recorded this information, now we can compare to what's happening today and draw a conclusion today that is that important and carries that much weight about evolution.

Obama Inauguration UFO ( )

Neurologica: Obama's UFO

Interview with Tim Minchin ( )

TimMinchin.com

Science or Fiction ( )

1. Researchers find that adding small amounts of chocolate to a cow’s feed increases their milk production by as much as 20%.
2. A new study reveals that animals that hibernate or burrow are less likely to go extinct.
3. A recently published review of research suggests that technology has caused a decrease in critical thinking and analysis skills.

Skeptical Quote of the Week ( )

Truth, sir, is a cow that will yield such people no more milk, and so they are gone to milk the bull

Samuel Johnson

S: The Skeptics' Guide to the Universe is produced by the New England Skeptical Society in association with the James Randi Educational Foundation and skepchick.org. For more information on this and other episodes, please visit our website at www.theskepticsguide.org. For questions, suggestions, and other feedback, please use the "Contact Us" form on the website, or send an email to info@theskepticsguide.org. If you enjoyed this episode, then please help us spread the word by voting for us on Digg, or leaving us a review on iTunes. You can find links to these sites and others through our homepage. 'Theorem' is produced by Kineto, and is used with permission.

References