Washington could be the first state to require labels on GMOs. Here are the stakes.

On Tuesday, Washington state residents will vote on whether to approve Initiative 522, which would require genetically modified foods sold in stores to be labeled accordingly. If it passes, it would be the first such law in the United States.

An image from an hourlong documentary on GMOs produced by Washington's public television network.

An image from an hour-long documentary on GMOs produced by Washington's public television network.

Here's the text of the law (pdf). Those in favor, including organic food companies and food activists, argue that Washington state residents have a right to know what's in their food. The "yes" campaign has raised $8.4 million, much of it from small donations and advocacy groups.

Those opposed, including various food and biotechnology giants, say the law could lead to higher prices at the grocery store and frivolous lawsuits. The "no" campaign has raised at least $22 million, with large out-of-state food companies and agribusinesses like Monsanto, Dupont Pioneer, Coca-Cola, and Kellogg donating heavily.

The vote in Washington state is likely the first of many labeling fights to come. At least 20 states are now considering similar laws, and a small-but-growing contingent in Congress is backing a bill to require mandatory labeling for genetically modified foods. So here's a primer on the broader debate:

How do you genetically modify food? Farmers have been selectively breeding crops for tens of thousands of years in order to produce desirable genetic traits. But that's not what's at issue here. Since the 1990s, scientists have been able to manipulate the genomes of crops and animals directly.

That might involve things like taking a few well-characterized genes from a different species (say, bacteria) and transplanting them into a crop (say, corn) to produce certain desired traits. This is very different from traditional plant breeding, and it's what is causing all the controversy.

Post archive photo from 2000: An agronomic research manager with Monsanto examines a test plot of corn genetically engineered to combat the destructive rootworm pest in the Shenandoah Valley. (Marc Kaufman/The Washington Post)

Post archive photo from 2000: An agronomic research manager with Monsanto examines a test plot of corn genetically engineered to combat the destructive rootworm pest in the Shenandoah Valley. (Marc Kaufman/The Washington Post)

Why would anyone manipulate genes like that? For a variety of reasons. Some crops are modified to be resistant to herbicides — such as Monsanto's Roundup Ready soybeans — so that it's easier to spray fields with weed-killer. By contrast, Bt corn is modified with a bacterial gene in order to secrete a poison that kills pests. That can reduce the need for chemical pesticides.

There are other potential uses, too: Golden rice has been modified to help alleviate Vitamin A deficiency among children in countries such as the Philippines. (So far, however, golden rice is still in the testing phase and has met fierce opposition from protesters.)

So there's no one single type of genetically modified food? Right. Simply saying that a food is "genetically modified" doesn't tell you very much. Genetic modification is a tool that can be used for many purposes.

In practice, biotech companies like Monsanto tend to focus much of their research efforts on traits like herbicide resistance and pest tolerance for major cash crops like corn and cotton. Yet other researchers, such as U.C. Davis's Pamela Ronald, are interested in harnessing genetic techniques to boost sustainable agriculture or addressing world hunger. (The latter tends to be a smaller slice of existing research, however.)

How prevalent are GM foods? More than 88 percent of the corn and soy planted in the United States is genetically modified in some way. Most of that ends up as animal feed or ethanol or corn syrup, which in turn gets into lots of foods. Cotton, sugar beets and canola are also common genetically modified crops. Roughly 70 percent of processed foods in grocery stores contain at least some genetically modified ingredients.

Is it really any safer? (PostTV)

Is it really any safer?

Are GM foods safe, health-wise? So far, there's been no good scientific evidence that they're harmful. At this point, billions of people around the world have been eating GM foods for decades. And numerous scientific studies have concluded that the genetically modified crops on the market pose no more of a risk than conventional crops.

Here's what the American Association for the Advancement of Science (AAAS) said in a 2012 statement: "The science is quite clear: crop improvement by the modern molecular techniques of biotechnology is safe." The European Commission agreed, after sifting through 25 years of research. So did the American Medical Association — although the latter is in favor of stricter pre-market safety testing.

A minority of scientists, however, insist that more research is needed before GM foods can be so definitively considered safe. In a dissent to that AAAS statement, 21 researchers argued that U.S. testing of genetically modified foods isn't stringent enough (see here for a closer look at that claim). They also argued that increased pesticide use — which can occur with things like Roundup Ready crops — may have health effects we don't yet know about. So, they say, why not label and let consumers make up their own minds?

Are genetically modified crops good or bad for the environment? So far, most government agencies are unconvinced that genetically modified foods pose an environmental threat. Here's the National Research Council in 2010: "Generally, GE crops have had fewer adverse effects on the environment than non-GE crops produced conventionally."

In some cases, GM crops can benefit the environment. Cotton that's engineered to be pest-resistant can allow farmers to use fewer chemical pesticides. Insecticide use in U.S. corn fields has fallen significantly since 1996 as genetically modified Bt corn has become more prevalent (see chart).

But there are also some legitimate concerns. For instance, farmers planting herbicide-resistant GM crops tend to use a limited range of herbicides on their fields, which can give rise to herbicide-resistant "superweeds." There's also the risk that genetically engineered traits could escape into nature — as apparently occurred back in May, when a never-approved strain of GM wheat made its way to an Oregon field.

That said, there are environmental risks with conventional crops too—those "superweeds," for instance, can also appear on non-GM crop sites. On balance, the National Research Council found genetically modified crops to have fewer adverse effects.

So what would Washington's law actually do? The law would require any food sold for retail that contains genetically-engineered ingredients to be labeled "clearly and conspicuously." Those labels would have to appear on the front of packaging. Restaurants would be exempt.

The bill sets out a detailed definition of "genetically modified," but note that there may be some gray areas here. Many biotech companies are now experimenting with new techniques (pdf), such as engineering specific proteins, that do not meet the traditional definition of "genetically modified." It's unclear how those might be affected by Washington's law.

What have past GM-labeling laws accomplished? Studies of labeling laws in Netherlands and China found they did not substantially affect consumer behavior. The same goes for labeling requirements in France. (That said, the labels in these countries were less prominently displayed than Washington state's law would require.)

One possible reason for the small impact is that labeling laws could make GM-free foods more expensive to produce — after all, retailers and manufacturers have to provide extensive documentation to prove food is not genetically modified. So, according to a paper (pdf) by the International Food Policy Research Institute, mandatory labeling laws might not affect the supply of non-GM foods much.

Many proponents of GM labeling would prefer the label go here, not out front. (bigstock)

Some proponents of GM labeling would prefer the label go here, not out front. (bigstock)

So what's the best argument against GM labeling laws? What can they hurt? Some critics of Washington's law have argued that it goes out of its way to stigmatize genetically modified foods in a way that's out of proportion to the risks involved.

Washington's law differs from other labeling laws by requiring that the label be placed on the front of the packaging, rather than in back with all the other ingredient information. "The front-of-package mandate in I-522 isn’t a reasonable attempt to inform consumers," writes science writer Ramez Naan. "It goes above and beyond that, to place a burden on GM foods that isn’t placed on tremendously more dangerous ingredients [like sugar or certain fats]."

Some scientists have raised related concerns: Back when California was considering a labeling law (which eventually failed), U.C. Berkeley's David Zilberman worried that labeling laws might "create a stigma effect" that will hinder future research into using GM foods to improve nutrition or help ameliorate the effects of climate change.

There are also fears that Washington's labeling law could lead to a flurry of frivolous lawsuits. Note that California's Prop. 65, which required companies to post warnings about chemicals, led to a slew of costly lawsuits and eventually had to be revised.

GMO protestors make nice signs. But do they have good points? (Eduardo Munoz / Reuters)

GMO protestors make nice signs. But do they have good points? (Eduardo Munoz / Reuters)

What's the best argument for GM labeling laws? It's true there are lots of scientifically unsupported claims about the harms of GM foods. But there are other, more nuanced arguments in favor of labeling, too.

Some critics of GMOs have argued in the past that labeling laws could force transparency on an industry that tends to be dominated by just a few large corporations like Monsanto and Dupont. See Tom Philpott of Mother Jones, who pointed out last fall, during the debate over California's labeling law, that giant agribusinesses have managed to fend off oversight for decades.

Others think labeling could help defuse a polarizing debate. Over at Grist, Nathanael Johnson has been spending months reporting on the science of genetically modified foods, talking to critics and scientists alike. His conclusion is that "the actual hazard associated with the GM foods is somewhere between negligible and non-existent." But, he says, there's still widespread unease among the public. Labeling might resolve that:

In a famous paper on risk perception, published in Science in 1987, Paul Slovic pointed out that people judge voluntary, controllable actions as much less risky than those that are involuntary and out of their control. Similarly, people see the unknown as much more risky than the known. Genetically engineered foods are, for most people, both unknown and uncontrollable.

There’s a simple, almost magical, solution to both these problems: labeling. Labeling makes the unknown known; it puts people in control of what is currently uncontrollable. It removes dread fear from the debate. ... If the rhetoric and emotions surrounding this issue cooled off we could begin a reasoned and overdue discussion about what tools we want to use to meet the agricultural challenges of the future.

Some defenders of genetically modified foods have come around to similar views. Ramez Naan, for instance, thinks the Washington law is fatally flawed. But he has also argued that labeling laws are inevitable — not least because 93 percent of Americans back them. "The only reasonable choice for GMO proponents now is to embrace labeling and help lead the process," he writes. "We should embrace it to help dampen consumer fear of GMOs."

What's the best argument that this entire debate has become far too polarized? Many people I've talked to tend to have strong views on this topic one way or the other. One exception was University of Minnesota's Jonathan Foley, who has been doing a lot of vital work asking how we can feed the world as the population grows and the planet warms.

"A lot of the fears about GMOs in the public debate are overblown," Foley told me last November. "But a lot of the promised benefits have been oversold too. I don’t see much evidence that GMO crops have done a lot for feeding the world, for instance."

Here's what he means: Genetic modifications have made certain crops — like corn or soy or canola — more profitable and often less labor-intensive. That's a boon to farmers. But, he notes, genetically modified crops haven't done nearly as much to date to boost crop yields significantly or alleviate food insecurity worldwide. And in the broad scheme, those are the really key issues.

His suggestion? Far more education about genetically modified foods, as well as more public investment into research — particularly in those areas that private companies are often neglecting.

Further reading: Washington state fight over GMO labeling is expensive and polarizing.

Brad Plumer
Brad Plumer covers energy and environmental issues, which ends up including just about everything from climate change to agriculture to urban policy and transportation. Follow him on Twitter at @bradplumer. Email him here.