Tomorrow Washington State voters will decide on The People’s Right to Know Genetically Engineered Food Act, also known as I-522. This initiative will mandate labels on all foods made with genetically modified organisms (GMOs) sold in grocery stores. It follows on the heels of last year’s Proposition 37, a similar ballot measure in California that drew national attention and massive campaign coffers on both sides of the issue. Proposition 37 was narrowly defeated, 51-49 percent.

In the final weeks leading up to Washington’s election, the battle over I-522 is proving to be as charged as the California campaign and as effective in fueling the national debate over how our food is grown, brought to market, and labeled (or not). If passed, I-522 would be the first voter-mandated GMO labeling law in the U.S.

Perhaps you’ve been interested in the issues surrounding GMOs for a long time, following the stories on GMOs published here on Civil Eats. For those of you who are new to the issues, or who have questions you were afraid to ask, we are publishing this primer with a rundown of the whats, whens, and whys, and how this issue got to where it is today.

What the heck is a GMO, anyway?

GMO is an acronym for Genetically Modified Organism.  It is a plant, animal, insect, bacterium or yeast that has undergone genetic modification, also referred to as genetic engineering (or GE).

Ahhh, genetic modification/engineering?

Simply put, the genetic makeup (aka DNA) of an organism is altered by removing or mutating one or more of its genes, or by inserting a gene from another organism. The result is a new variety of the original organism.

How is genetic modification/engineering different from conventional plant breeding, including crossbreeding and hybridization? 

Conventional breeding is actually a form of genetic modification. For thousands of years, farmers have been “sexually crossing” closely related plant species for sundry reasons, from improved yields to disease resistance. The practice helped to bring about tasty hybrids like the tangelo and pluot and the Honeycrisp apple. It’s how 19th Century botanist Luther Burbank developed a disease-resistant potato (ultimately named the “Idaho”) that would be hardy enough to help Ireland recover from its potato blight.

But for the purposes of this discussion, we’re talking about genetic engineering conducted in a lab setting. This technique, called “transgenic technology,” has been practiced only in recent decades. Unlike conventional breeding, genetic engineering invites crossbreeding of unrelated species, taking specific genes from one species and inserting them into another. (The process has been described as using “chemical scissors.”) This new wave of genetic engineering is being used for medical and pharmaceutical research, as well as in agriculture.

What crops are GE?

Transgenic technology has been used to develop dozens of genetically-engineered crops both for animal and human consumption. Currently, there are nine GE crops in production and in the global food supply: Alfalfa, canola (a variation of rapeseed), corn (both field and sweet), cotton, Hawaiian papaya, soybeans, sugar beets, yellow crookneck squash, and zucchini. (GE papaya is the only engineered fruit currently in the marketplace.)

About 90 percent of all corn, cotton, and canola grown in the U.S. comes from genetically-engineered seeds. About 95 percent of sugar beets (which are refined into sugar) are GE, and 93 percent of soybeans.

The United States is the world leader of GE crop production, at 170 million acres (about half of all U.S. cropland).  The U.S. and four other countries—Canada, Argentina, Brazil, and India—grow 90 percent of all GE crops worldwide.

How long have GE crops been on the scene? 

GE crops were first introduced in the U.S. in 1996. But since 1994, dairy cows have been treated with a GE bovine growth hormone to increase milk production.

Who makes genetically-engineered seeds?

In the 17 years since GE crops were introduced, genetically modified seeds have become a multi-billion-dollar global industry dominated by a handful of multinational conglomerates. Monsanto, DuPont, and Syngenta are among the major players in GE seeds, capturing nearly half of the global market share. These companies, along with BASF, Bayer and Dow, also dominate the global market for herbicides and pesticides.

How do genetically-modified seeds work?

Genetically-modified food crop seeds fall into two general categories: Herbicide resisters and pesticide creators.

The most widely used herbicide among GE crops is glyphosphate, also known as Roundup, its brand name. Herbicide-resistant seeds are commonly known as “Roundup Ready.” They are modified to be immune to weed killers. So a farmer can spray weeds with glyphosphate without fear of killing crops. “Roundup Ready” crops include alfalfa, canola, corn, cotton, sugar beets, and soybeans.

Corn and cotton seeds have also been re-designed as pesticide creators, plants that are insect proof. They are modified with the addition of a gene from Bacillus thuringiensis, a naturally occurring soil bacterium commonly known as Bt. The Bt gene effectively turns the plant into an insecticide, making it deadly to insect predators such as the corn rootworm, earworm, and the cotton bollworm.

Other than warding off weeds and pests, what are the benefits of GE crops?

Ever since GE seeds have been in the marketplace, the industry has touted two key advantages: Increased crop yields, a solution to feeding the world, and decreased use of herbicides and pesticides, which helps farmers save money and arguably is better for the environment.

“Roundup agricultural herbicides and other products are used to sustainably and effectively control weeds on the farm,” according to the Monsanto web site. “Their use on Roundup Ready crops has allowed farmers to conserve fuel, reduce tillage and decrease the overall use of herbicides.”

From the DuPont web site: “DuPont Crop Protection works hard to understand the needs of growers as they rise to the challenge of feeding a growing world. We use inclusive thinking to create answers in insect, weed, and disease control that help growers improve the quality and yield of their crops, and the productivity and sustainability of their farming operations.”

Are the industry claims proving true?

Herbicide-resistant crops have spawned one unexpected outcome: herbicide-resistant weeds. Scientists, industry analysts, and government researchers alike have documented an outbreak of several species of Roundup-resistant “superweeds,” which are spreading in epidemic fashion on GE cropland. Superweeds first appeared in 2000 in a Delaware soybean field; they have since spread to more than 20 states.

According to a three-year survey of GE farmers by the agribusiness market research firm Stratus, 61 million acres of U.S. cropland in 2012 were “infested with glyphosphate-resistant weeds, almost doubling from 2010.” This accounts for about 30 percent of GE cropland.

Typically several feet tall, superweeds are strong enough to stop a combine, forcing farmers to use more glyphosphate, the opposite of what had been promised. Cotton farmers have been hit particularly hard; over the past decade, a superweed known as pigweed has threatened cotton production and forced some growers to abandon their crops.

In a 2010 report, the National Research Council said “the repeated use of glyphosphate as the only weed-management strategy favors the evolution of glyphosphate-resistant weeds.” The report warned that “eventually, repeated use will render glyphosphate ineffective.” The solution, according to the report, is to use additional and perhaps even more potent weed killers.

To that end, agrichemical company Dow has sought USDA approval of an herbicide containing 2,4-D (a major ingredient of Agent Orange, the notorious chemical used during the Vietnam War), as well as 2,4-D resistant corn seed.

Charles Benbrook, a Washington State University research professor, has been monitoring both herbicide and pesticide usage among GE corn, cotton, and soybean growers. Using USDA data, he found that between 1996 and 2011, combined herbicide and pesticide amounts increased by 404 million pounds, or 7 percent. His findings were published last year in the peer-reviewed journal Environmental Sciences Europe. He warns that the introduction of 2,4-D-resistant crops would increase herbicide use by 50 percent.

Nine GE crops don’t seem like much. Where do I see them in the grocery store?

The vast majority of GE crops go into livestock feed. What’s left for human consumption goes into processed foods. Seventy to 80 percent of processed and packaged foods on supermarket shelves—breakfast cereal, sandwich bread, cookies, crackers, chips, salad dressing, ice cream, cake mix, frozen entrees, to name a few—contain GE-derived ingredients, but you’d only know that by reading through the often long list of ingredients.

Some of the more commonly known GE ingredients in processed foods are the sweetener Aspartame, high-fructose corn syrup, corn starch, soy lethicin, molasses, sucrose, cottonseed oil, soybean oil, maltodextrin, textured vegetable protein and flavorings, both “natural” and “artificial.”

Unless they are labeled organic or non-GMO verified, the following supermarket items are presumably produced directly or indirectly from GE ingredients: Canola oil, soy milk, tofu, soy sauce, frozen veggie burgers, corn chips, tortillas, cornmeal, grits, beef, chicken, pork (GE corn and soy are major components of animal feed for conventionally raised livestock), eggs, milk, and dairy products.

As mentioned earlier, dairy cows have been treated with a synthetic growth hormone known as rBST since 1994. Consumer demand for organic milk or milk without synthetic growth hormones forced many non-organic commercial dairies to reconsider their practices. Voluntary labels such as “not treated with rBST” have been in place in the U.S. since 2007.

Is GE food safe to eat?

Depends on whom you ask. Back in 1992, the FDA determined that GE food is “substantially equivalent” to non-GM food and is therefore exempt from the definition of “food additive.” As such, GE corn and its brethren are “Generally Recognized as Safe” (AKA GRAS) under the Federal Food, Drug and Cosmetic Act and do not require pre-market approval.

At the time this policy was enacted, the deputy commissioner of policy at the FDA was Michael Taylor, appointed in 1991. Prior to his appointment, Taylor practiced law at King & Spalding, a firm that represented Monsanto.

The 1992 FDA policy has been the basis for much of the industry’s safety claims. On the Food Safety page of the Monsanto Web site, there is no citation of clinical studies done to determine the effects of GE products on human health. In response to the question, “Why aren’t you running human clinical trials on GM crops?” on the company’s FAQ, Monsanto says: Because existing food crops are recognized as safe, the logical starting point for safety assessment of a GM food is to ask ‘what’s different?’

To date, there have been no long-term, peer-reviewed studies of GE food on human health. The closest thing in recent years is research done on pigs. Earlier this year, a U.S.-Australian research team studied the impacts of a GE versus non-GE diet on newly weaned pigs on an Iowa farm. In their 22.7-week blind study, the team found that the pigs fed a GE diet had a higher rate of stomach inflammation (32 percent versus 12 percent for non-GE diet). They also found that females fed a GE diet had a 25 percent heavier uterus, a possible indicator of disease. The results were published in the peer-reviewed Journal of Organic Systems in June. The industry vigorously opposed the study, with British journalist, author and GE supporter Mark Lynas describing it as “propaganda dressed up as science.”

In the absence of long-term studies on humans, it is difficult to say with certainty if GE crops are safe. The industry did not anticipate the explosive growth of superweeds; does it really know for sure what the long-term effects of eating GE foods will be? In the words of Gary Hirshberg, co-founder of Stonyfield Farm and chair of the Just Label It campaign, “No one can now definitely prove that the genetic engineering of food does or does not pose a health or safety threat to any of us. But there is no question that the use of GE crops is increasing our exposure to herbicides and Bt toxins.”

Other than California’s Prop 37 last year, are there other state-level GE bills or initiatives underway?

Connecticut and Maine passed labeling laws earlier this year, but they won’t go into effect until neighboring states pass similar laws. More than 20 states have introduced labeling legislation this year alone.

There is proposed legislation on the federal level as well. In April, Sen. Barbara Boxer (D-CA) and Rep. Peter DeFazio (D-OR) introduced The Genetically Engineered Food Right-to-Know Act, which would mandate the FDA to amend the Federal Food, Drug and Cosmetic Act and require GE foods to be labeled. Both the Senate version (S.809) and the House version (H.R. 1699) remain stalled in their respective committees.

Where do other countries stand on GE labeling?

More than 60 countries have GE labeling laws in effect. The European Union has required labels on GE food since 1997.

Additional Notes of Interest

Earlier this year, Whole Foods Market announced that regardless of labeling legislation, it would remove all GE foods from its shelves worldwide by 2018.

Photo: One San Franciscan on Prop 37. Credit: Lynn Friedman/Flickr

A version of this story originally appeared on Crosscut.com.