Does plastic make you fat?

December 8, 2008

Bisphenol A, an additive in plastic that made Nalgene water bottles go out of fashion, may be worse than carcinogenic – it may be fattening. Angry Toxicologist (blogging once more! Yay!) posted on a new study that found a link between BPA and metabolic syndrome.

The Angry Toxicologist writes:

It’s not clear how the BPA does this, though it’s likely due to it’s ability to disrupt hormones. In the study, estradiol (the potent estrogen) had the same effects on breast and abdominal fat tissue. They used human fat tissues that were removed from patients undergoing other procedures. The one issue I have here is that it may be that those undergoing the procedures have cells that react differently than the rest of the population. The samples came from patients getting breast reduction sugery, a tummy tuck, or gastric bypass. The people may have bodies that like to build up fat anyway, especially in the last two. Even if this is true, however, it at least means that some people are effected by BPA; in fact, it may be those who can least afford it.

There was a wide variety of effect of BPA (i.e. some patient’s tissues were sensitive to it and others weren’t). However, on average, BPA was more potent than estradiol at equimolar doses (that’s an equivalent dose based on the number of molecules, not weight, for those of you who didn’t take or don’t remember chemistry). Yikes!

Anyway, here’s the kicker. The levels were environmentally relevant. 1-10 nM are common in people (some up to 20 nM). The study found effects at 0.1 and 1.0 nM. Good ‘ole plastics. Is there anything they can’t do?

Yikes! You can keep your opaque white Nalgene bottles, though – they’re high-density polyethylene and do not contain BPA.


Talk amongst yourselves – I’ll give you a topic

June 23, 2008

I had all kinds of intelligent things to write, but I’m somewhat under the weather today, so I’ll just link lazily instead.

  • Is there too much doom and gloom in conservation outreach? Mark Powell says yes, Rick MacPherson says no, Mark says YES NEENER NEENER, Rick says NO PBBBT. Me, I try to enjoy the gloom as much as possible – all those beautiful opportunities for black humor that my ancestors never even dreamed of. In fact, maybe this discussion can be settled with a klezmer danceoff!
  • The New York Times Magazine has a feature on trash in the ocean. It focuses on Alaska, which has the same trash accumulation problem as the Northwest Hawaiian Islands – it’s getting trash from the North Pacific Gyre. Volunteers in the Kenai Fjords picked 30 tons of trash off just one beach.

Is there really six times more plastic than plankton in the North Pacific Gyre?

June 10, 2008

Because of all the traffic on this post, I wanted to clarify that I am completely convinced that there is lots of plastic in the North Pacific Gyre, and that it is a serious environmental problem. My issue with the plastic:plankton ratio is that it doesn’t accurately measure the amount of plastic.

The Algalita Marine Research Foundation is great at raising awareness of the problem of trash in the North Pacific Gyre. They’ve tirelessly lobbied for political change, coined terms like “plastic soup,” worked in the schools, and are sailing the Junk raft to Hawaii as we speak. However, as part of their quest to make the enormity of the plastic problem understood, they’ve been claiming that there is six time more plastic than plankton in the North Pacific Gyre. The 6:1 ratio has appeared in PBS, The Seattle Times, and has been repeated all over the internet.

Though I admire Algalita’s work, the 6:1 plastic:plankton ratio is deeply flawed. Worse, it is flawed in a direction that undermines Algalita’s credibility: It may vastly underestimate plankton and overestimate plastic. Here’s why, based off the methodology published in Moore et al’s 2001 paper in Marine Pollution Bulletin.

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The law of unintended consequences strikes China’s plastic bag ban

June 9, 2008

Jocelyn Ford of the the Science Friday blog lives in Beijing, and she has posted an account of the on-the-ground repercussions of China’s plastic bag ban. China banned extremely thin single-use plastic bags, but not the thicker bags more common in the US. Ford admits that the new bag surcharge has made her more careful about bringing her own bags to the food market, but worries that banning thin bags has only led to more widespread use of thick bags:

Take my local hole-in-the wall shop that sells stuffed pancake (yum!) Until last week, the shop did takeaway orders in ultra thin bags less than 0.025 millimeters, or 0.00098 inches thick. It’s now upgraded– the shop not only uses thicker bags, it’s ordered bags with the shop name on them. The shopkeeper proudly told me they were “environmentally friendly.” Looks to me like the new regulation has encouraged him to add to the garbage and pollution problem. The tiny bags are not easy to reuse.

In a classic case of the law of unintended consequences, Ford says that many shops have also started to give away free paper bags, which create more air and water pollution than plastic bags. (It’s true! See this handy chart from the Washington Post.) Ford believes that China should have legislated biodegradable bags – except, as she point out, they are made from corn.

So are biodegradable bags a solution? The corn starch bags Ford mentions are still under development, and they are based off ethanol biofuel byproducts. Since corn ethanol biofuel has proved to be food-price debacle, this is probably not the solution. Most commercially available biodegradable bags are based off a mixture of corn starch and petroleum-based polyesters. While they do biodegrade (which does solve the problem of cute large animals choking and drains clogging), it means that biodegradable bags are both competing with food supplies and polluting the environment with tiny molecular- and cell-sized bits of polyester. Little bits of plastic can be a huge problem at the base of the food chain, due to accidental ingestion by non-charismatic but ecologically critical animals like insects and earthworms

I still think that plastic bag bans are a move in the right direction, but Ford’s anecdotes about the Chinese ban show that a nuanced approach may be necessary. Should all disposable bags, including paper, be taxed? How can the Chinese government encourage people to reuse bags instead of simply switching types of disposable bag? And what approach might the US (when we finally catch up with Ireland, Bangladesh, and South Africa) take to control the plastic problem?


So we’ve got this trash-filled gyre, right? Can we fix it?

May 14, 2008

Before Miriam posted her most excellent explanation of what the North Pacific Trash Gyre really looks like, I had a vision for how to clean it up: A multinational fleet of mighty ships, their prows split wide open to admit the polluted sea water, slurping it up into giant filters to pick up the plastic, and spitting out clean ocean out the back. I can see them trawling back and forth over the ocean until, eventually, some bearded guy in a yellow rain slicker and a sou’wester wipes his brow, turns to his first mate and says, “Ayuh, we finished cleanin’ the watah.” And then Miriam posted, and I learned just how difficult cleaning up a Texas-sized ocean of trash with plastic at multiple depths really would be. Alas.

So how do we fix it? Over at Blogfish, Mark Powell lined up three proposed solutions: more recycling of plastic, ban the worst products, or a massive reorganization of our economy. In the comments, someone proposes plankton trawls, which is pretty close to my vision big ocean filtering boats. Unfortunately, there are serious problems with all of these ideas: banning the worst plastics might reduce the growth of the trash heap, but it won’t exactly clean up the mess itself. Same problem with recycling. I’m still keen on the trawl/ocean sucking barge idea, but there is that pesky problem of bycatch, in that you’d filter out any fish or plankton living in a marine area larger than Texas.

But then I recalled something about microbes that eat oil, when we have massive oil spills. Well, heck, plastic is made of hydrocarbons, right? Maybe there’s something that can eat plastic.

And thus I enter the fabulous world of bioremediation, the notion that we can fix biological problems with other bits of biology, most commonly by using bacteria to turn something toxic or polluting into something non-toxic or non-polluting. Back in 2005, Spanish scientists studied microbes that ate oil after a major spill off the Spanish coast. And recently some University College Dublin scientists evolved a bacteria to eat polystyrene, the main ingredient in styrofoam.

Now there’s companies that specialize in this stuff. A clean-up company called Ecochem claims you can use micorbes to clean up everything from the MTBE added to gasoline to fuel and oil spills that have seeped into the earth. I also found a fungus that eats certain hard-to-recylce plastic resins that get used in particle board and cars. So that seems promising, but I’m not sure fungus will do all that well in the water.

So, I’m afraid my search came up short, which isn’t too surprising, because if there was a plastic-eating microbe out there, we probably would have already set it to work on our landfills, let alone the gyre. Still, I have to think that if bacteria eat oil and styrofoam, then we can’t be too far off from finding one that will help us along with our plastics clean up. In the meantime, maybe those giant trawlers aren’t such a terrible idea?


Greenpeace needs remedial oceanography

January 31, 2008

Eric found this Greenpeace animation, which tries to demonstrate trash accumulation in the North Pacific Gyre. It’s really pretty – too bad the oceanography is entirely wrong. Why is the California Current sweeping through the Central Valley? (Does this mean LA has finally been swept out to sea?) The Alaska Current is not actually over the land of Alaska. And there’s an entirely novel gyre over by Japan – the Kuroshio Current has run away to Kamchatka. Compare:

Still of very very wrong Greenpeace animation:

Actual correct currents (courtesy Ocean Motion):

north-pacific-circulation.jpg

Oh, Greenpeace – I kind of love your costumes and your earnestness and your enthusiasm. I’m glad you’re out there lobbying and protesting. But Greenpeace, when you’re writing about the North Pacific Gyre you can’t just put the ocean currents every which way. Having the Kuroshio (the Gulf Stream of the Pacific) going the wrong way is particularly harmful to your goal, since it is the Kuroshio that brings plastics from Asia into the gyre. And when your incorrect figure is the second google hit for “North Pacific Gyre Map” – well, that’s way more embarrassing than being the guy in the whale suit.


2076: Peak Oil Odyssey?

October 11, 2007

I love books about dystopias, apocalypses, and world-endings. Parable of the Talents, Y: The Last Man, World War Z, The Dark Tower series…and that’s just off the top of my head. Maybe I like being scared, or maybe I like having my bad attitude about human nature confirmed. But I’m not really worried about most of scenarios for world-ending – I don’t think a plague will kill all the men, we don’t have super-intelligent robots who look just like us, and there are no zombies – yet. (But if there are zombies, Eric and I are SO on top of it. We have a zombie invasion plan that’s way more detailed than our earthquake/fire/hurricane plan. What? What’s wrong with that? )

But there is one dystopia mechanism that may hold some water – Peak Oil. Peak Oil is

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