There Are Probably No Nanoparticles in Your Food… At Least, Not Intentionally

Recently, Mother Jones posted an article about “Big Dairy” putting microscopic pieces of metal in food. Their main source is the Project on Emerging Nanotechnologies and its Consumer Products Inventory, a collaboration between the Wilson Center and Virginia Tech. Unfortunately, the Mother Jones piece seems to misunderstand how the CPI is meant to be used. But another problem is that the CPI itself seems poorly designed as a tool for journalists.

So what’s the issue? The Mother Jones piece mainly focuses on the alleged use of nanoparticles of titanium dioxide (TiO2) in certain foods to enhance colors, making whites whiter or brightening other colors. First, the piece makes an error in its description of TiO2 as a “microscopic piece of metal”. Titanium is a metal, but metal oxides are not, unless you consider rust a metal (which would also be wrong). But another issue is “microscopic”. Just because something is microscopic, which generally means smaller than your eye can see, doesn’t mean it’s a nanomaterial. The smallest thing you can see at a normal reading distance is about a tenth of a millimeter, which is 1000 times bigger than the 100 nanometer cut-off we typically use to talk about nanoparticles.

A clear glass dish holds a bright white powder.

Titanium dioxide is a vivid white pigment, even as macroscopic particles.

And that’s what confuses me most here. As you can see above, titanium dioxide is white as a powder, but in that form it’s several hundred nanometers wide at minimum, if not on the scale of microns (1000 nanometers). In fact, nanoparticles of TiO2 are too small to scatter visible light and so they can’t appear white. A friend reminded me how sunscreens have switched from large TiO2 particles to actual nanoparticles precisely because it helps the sunscreen go on clearer. I’m not naive enough to think food companies wouldn’t try to cut a buck to help improve and standardize appearances, but I also don’t think food scientists are dumb enough to pay for a version of a material they can’t fulfill the purpose they’re adding it for. So TiO2 is probably used in some foods, but not on a nanoscale that radically changes it’s health properties.

But I don’t entirely blame Mother Jones. The thing is, the main reason I had a hunch the article seemed wrong is because one of my labmates at UVA has been working with TiO2 nanotubes for the last three years, and I’ve seen his samples. If I didn’t know that, and I just saw PEN include TiO2 on its list of nano additives, I would be inclined to believe it. PEN saw the Mother Jones piece and another similar article and responded by pointing out that the inventory categorized their inclusion of TiO2 in the products as having low confidence it was actually used. But their source is an environmental science paper including actual chemical analyses of food grade TiO2, so why do they give that low confidence? Also, PEN claims the CPI is something the public can use to monitor nanotechnology in products, so maybe they should rethink how confident they are in their analysis if they want to keep selling it that way.

The paper CPI references in the TiO2 claim is interesting too. That paper actually shows that most of the TiO2 is around 100 nm (figure below). But like I said, that’s kind of pushing the limit on how small the particles can be and still look white. It might be that the authors stumbled across a weird batch, as they note that in liquid products containing TiO2, less than 5% of the TiO2 could go through filters with pores that were 450 nanometers wide. Does the current process used to make food grade TiO2 end up making a lot of particles that are actually smaller than needed? Or maybe larger particles are breaking down into the smaller particles that Weir sees while in storage. This probably does need more research if other groups can replicate these results.

A histogram showing the distribution of particle sizes of TiO2. Categories go from 40 nanometers to 220 nanometers in intervals of 10. The greatest number of particles have diameters of 90-100 or 100-110 nanometers.

Distribution of TiO2 particle sizes in food grade TiO2. From Weir et al,

Scientists Still Aren’t Really a Political Bloc

The Atlantic recently published an article in the “but Democrats are anti-science too!” genre that seemed to get really weird in the end. Perhaps this is because author Mischa Fisher is a staffer for Republican Congressman Randall Hultgren of Illinois. Honestly, a lot here isn’t new, and I’ll link to my response to Alex Berezow’s book and interview with reason. The big thing, as I said before, is that we’re not given many numbers about the prevalence of anti-scientific views on the left, especially in comparison to their support by the right (fringe views on chemicals show up in New World order conspiracy theorists on the right and granola groups on the left). The only ones Fisher gives are about evolution and creationism and views of God, and I don’t think most scientists actually fret over that in science policy things.

And that’s where I lose my understanding of Fisher’s piece. He seems to be conflating scientists, secularists/skeptics, and Democrats as whatever best fits the argument he makes in each paragraph. There’s no shortage of scientists writing articles attacking chemophobia and irrational fears of GMOs from groups on the left and attacking any science cuts. Nature wrote a pretty balanced review of science policy during Obama’s first term. And there have been many revolts by scientists against policies the administration has pursued. Most scientists don’t care about your view of God, and many want people to appreciate that science doesn’t have to kill religious faith. The American Association for the Advancement of Science came out against California’s GMO labelling proposal last year.

At the end, Fisher says “there is a second, larger reason why it’s important to keep science bipartisan—and why cheap shots about Republicans and science are dangerous. The politics of the immediate will always trump the politics of the long term.” But that just seems to lump in all scientists as knee-jerk Democrats again, which isn’t true. It also seems hard to argue how most Republican politicians do believe in global warming or care about science funding when the members who rise to positions of influence on science policy don’t believe in these things. See: Rep. HallRep. Rohrabacher, and Rep. Smith on the House science committee. And while Fisher says Obama’s budgets have been harmful to basic science, many Republican politicians don’t seem to understand the point of basic research.

Hard Scientists Should Care About the NSF’s PoliSci Woes

Alex Berezow wrote an op-ed in USA Today defending the decision to defund the NSF’s political science programs aside from projects “promoting national security or the economic interests of the United States”. Berezow is also co-author of Science Left Behind, a book looking at anti-science tendencies on the left half of the political spectrum, which I blogged a bit about last November. And then the piece tapers off into something about scientists being too Democratic and they’re like a lobby and it just kind of becomes a generic cut the budget piece by the end. Needless to say, I’m not much more convinced by this op-ed than by the book or his interview with reason.

He starts by pointing out that political scientists are predictably outraged, but is confused why natural scientists are angry. He links to theoretical physicist Sean Carroll’s post on the funding cut and calls it an overreaction because he quotes “First they came”. Nazi overtones might be a bit much, but the analogy of continually chipping away at something seems valid. Berezow seems to think the fact that “relevant” political science could still be funded means a hard scientist shouldn’t ever worry about this. But a lot of hard science isn’t immediately practical. Carroll works in cosmology, which is basically abstract physics and abstract astronomy, so it seems entirely reasonable for him to worry about cuts to grants for research projects that won’t generate immediate economic benefit. We’ve already seen an attempt to go down the slippery slope with Lamar Smith’s proposed amendments to limit NSF funding in all fields to only projects relevant to economic or defense interests.

Berezow also claims that scientists act like too much of a partisan interest group since they only attack Republicans. While it’s true the Coburn amendment was approved by a bipartisan vote, that was part of a compromise to keep funding the government past sequestration. And Republicans have repeatedly offered similar amendments in the past, even when there weren’t such pressing budget concerns. It also seems ironic that despite two of Coburn’s amendments being incorporated into the bill, he still voted against it. Part of the logic behind the scientists are an interest group claim is how often they identify with Democrats. The survey does show that scientists are more Democratic and liberal than the general public.  This may lead to a disconnect between scientists and the public on some issues, and it merits study, but there’s no clear mechanism explaining it. But Berezow also seems to be including social scientists in his definition of scientists. The survey everyone talks about is focused on natural scientists. While some social science fields are also filled with liberals, I believe that political science and economics have a stronger Republican/conservative presence. 

Scientist ideology

Also, if politicians are going to go after interest groups, there are many with more votes to grab than a scientist bloc. In 1999, there were only about 3.5 million people with STEM degrees working in science and engineering fields. But if we’re talking about scientists as a interest group, we need to separate them from the engineers. Engineers are more likely to work in industry instead of in the public sector or academia than scientists, and also tend to be more evenly split along party and ideological lines. In 2011, about 35000 people graduated with doctorates in physical, life, and social sciences and engineering. Although this includes engineers, the fact that this only looks at people graduating with doctorates increases the odds that they will be doing basic research for the government or academia. Not all of those people are American citizens, though, and so they won’t vote. I don’t know the number for social sciences, but international students now make up almost half of all natural science and engineering grad students, so that already narrows the voter pool to like 25000 new group members a year (assuming nearly all social science PhDs are American citizens, for some reason). And not all these people will end up being funded by the government, either in a government agency or by public grants to universities. 27% of life science PhDs, 54% of physical science PhDs, and 71% of engineering PhDs went to work in industry in 2011. Factoring that in, a “government-dependent scientist” bloc would only grow by about 14000 votes a year. I think that is the rounding error of a decent get out the vote project.


Why Lamar Smith Doesn’t Seem to Understand Science

So we’ve looked at the research that seemed to motivate the following criteria that Congressman Lamar Smith (R-TX) has proposed that all NSF-fund research be certified as fulfilling:

  1.  ”… in the interests of the United States to advance the national health, prosperity, or welfare, and to secure the national defense by promoting the progress of science;
  2. “… the finest quality, is groundbreaking, and answers questions or solves problems that are of utmost importance to society at large; and
  3. “… not duplicative of other research projects being funded by the Foundation or other Federal science agencies.”

Now I’d like to break down why these criteria reflect a poor understanding of science and the National Science Foundation. Let’s just go through each point.

  1. First, Smith has the theoretical point of NSF backwards. The legislation that founded NSF put the mission “to initiate and support basic scientific research and programs to strengthen scientific research potential and science education programs at all levels in the mathematical, physical, medical, biological, social, and other sciences” before Continue reading

In Praise of Social Science and Science Studies at NSF

Consider this a slightly belated reaction (and a slightly different take) to the proposed bill from Congressman Lamar Smith that would propose the National Science Foundation certifying all research is

  1.  “… in the interests of the United States to advance the national health, prosperity, or welfare, and to secure the national defense by promoting the progress of science;
  2. “… the finest quality, is groundbreaking, and answers questions or solves problems that are of utmost importance to society at large; and
  3. “… not duplicative of other research projects being funded by the Foundation or other Federal science agencies.”

I’d like to address why requiring ALL projects funded by NSF to meet all these criteria is bizarre (especially 3, preventing the funding of multiple research paths or even funding what would essentially be the  reproducibility of an experiment suggests Smith literally does not know how scientific research is done), but I’ll save that for a future post. But for now I’d like to address what seems to be some of the underlying motivation of the first criterion by looking at the projects Smith seems to be concerned by.

Continue reading

Physics Education, in a Bit More than a Minute

MinutePhysics, an extremely popular YouTube channel that explains physics topics (though typically in a bit more than a minute), posted an “open letter to President Obama” about reforming high school physics.  Here’s the video, and my thoughts are below.

I actually have conflicting feelings about this. First, I would point out we do cover some of that, but not in physics. In my district, the Big Bang and astronomy were covered in an “integrated science” class on Earth and space science and some basic physics. And for some weird historical reason, we’ve decided that atomic structure is a chemistry topic until you get to college (I calculated the energy of nuclear mass defects in my first high school chemistry class, and that is straight-up E=mc^2) while high school physics is just elementary mechanics and E&M, probably out of some combination of bureaucratic inertia and a view of what was considered “practical” when these curricula were standardized. 

I honestly think the way we teach physics and chemistry in high school now prevents us from adequately covering modern physics. Quantum mechanics doesn’t really have any conceptual overlap with mechanics at this basic level and so it’s hard to integrate into the physics curriculum. This is also the view of some of advocates of a so called “Physics First” curriculum; the standard curricular divisions of high school biology, chemistry, and physics don’t really make sense given the way modern science works. One group advocated just really trying to integrate all three subjects and just have a three-year science sequence that isn’t separated as much by field. That would help remove any potential turf war between what parts of atoms are physics or chemistry and what biochemistry is biology or chemistry.

As an aside, relativity actually seems like it would be doable in high school. Or at least the only bit we cover in undergrad physics.  The Lorentz transformation is just algebra, and honestly that’s enough to help you understand a lot of its relevance to life (GPS correction, length contraction, etc). If I could propose one dramatic change to how we approach high school physics, I would honestly be okay with less emphasis on modern physics and more on just the general idea of energy. Physics (and really all of nature) is about minimizing energy.

Should Science Majors Cost Less?

The Atlantic has just published an interesting article: should public universities charge less for majors the state considers to be economically important?  The idea is a proposal from a Florida higher education task force.  The article brings up some immediate problems that come to mind, namely that it can be hard to predict specific majors that will be important over long periods of time and that this system and that students aren’t equally good at all majors.

I can also think of some other problems.  First, science and engineering majors actually require big capital investments from colleges.  They require lots of equipment and materials for labs.  Lowering the “cost” of these majors to students puts more of the cost needed for education on the university.  I could also see this system becoming gamed by smaller schools.  The actual proposal doesn’t just refer to STEM majors, it’s about any major the state considers important to its industries.  According to the Atlantic article, the Florida government has already designated the STEM disciplines, some education specialties, health fields, emergency and security services, and “globalization” as “strategic areas of emphasis”.  It’s not stated, but I would assume the state would help schools make up the difference between normal tuition and the price for discounted majors.  But what’s to stop a school from choosing to focus on say education and foreign affairs to get extra money from the state, and have a bare-bones science program so the extra money can go to other expenses?  Or who’s to say a school won’t try to encourage as many kids as possible from joining full or extra price majors to get more money, especially if an influx of STEM students on discounted tuition were to severely affect finances for labs?

On a less practical note, I would also worry this might homogenize the schools.  There’s a lot to learn from meeting people of different majors in college, or just meeting people who are really passionate about their field.  If a lot of friends are just majoring in mechanical engineering because “it’s cheap”, I wonder how effective they would be.  And what ideas they might never have if they never run into a philosophy or music major.