What is methyl iodide, and why is it in your produce?

Flickr photo by sigusr0, http://www.flickr.com/photos/sigusr0/1460105322/

If you’ve been to a farmer’s market lately, you may have noticed that it’s peak strawberry season. But you may also have noticed a sign next to many strawberries with the label, “Pesticide Free” – even when they aren’t organic.

That might be because last December, California approved the use of a controversial pesticide called methyl iodide, which would be used primarily on strawberry fields. But just last week, the D.C.-based Environmental Working Group released a report ranking strawberries as the third most pesticide-laden produce – behind apples and celery.

The controversy around the use of methyl iodide has some consumers asking more questions about where their strawberries are coming from, even when they might not know that much about the pesticide. KALW’s Laura Flynn went to the Berkeley Farmers’ Market to see exactly what some consumers there know about methyl iodide.

MOLLY GRAYDEN: You know, I guess it’s the thing to replace methyl bromide, or something? It’s very, very toxic.

MANUEL CARRASCO: I’ve noticed with just about anything that begins “methyl” is probably bad for me.

GRAYDEN: I guess there’s a plan to start using it.

CARRASCO: I avoid those sorts of products. I don’t need them.

CLAUDIA AVILAR: I think it doesn’t belong in our food system.

GRAYDEN: I think it’s a bad idea.

AVILAR: It goes off in the runoff water.

GRAYDEN: Not just for consumers, but for farmers and people who live in communities where strawberries and other produce is grown.

AVILAR: It’s basically a poison and it really doesn’t serve a purpose. I mean, it’s not necessary.

There’s been enough concern over methyl iodide that within days of the pesticide’s approval, environmental groups filed a lawsuit against the government. California counties have started issuing permits for use of the pesticide, but protests against its use continue.

KALW’s Max Jacobs sat down with Dr. Susan Kegley, a chemist and consulting scientist for Pesticide Action Network, one of the organizations involved with the lawsuit. She explained exactly what methyl iodide is, and why it has so many people concerned.

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DR. SUSAN KEGLEY: Meythl iodide is a chemical that is used in chemical laboratories to do organic synthesis, and the reason it works is that it’s very reactive, which is one of our concerns about releasing it to the environment. It reacts pretty much right away with biological molecules like DNA and can cause damage to cells, to tissues, and pretty much every living thing it comes in contact with.

MAX JACOBS: That’s the position of the Pesticide Action Network. The state government argues that with the proper regulation, methyl iodide is safe to use for agricultural purposes. The California Department of Pesticide Regulation declined to comment on the record for this story, but they did provide some information regarding their decision. In a written statement, the DPR says, “Methyl iodide is the most evaluated pesticide in the department’s history.” And this pesticide “can be used safely under its toughest-in-the nation health-protective measures, including stricter buffer zones, more ground water protections, reduced application rates and stronger protections for workers.”

Methyl iodide is used as a fumigant, which means that it’s not actually sprayed on the produce.

KEGLEY: It’s a liquid that very readily is transformed into a gas at average temperatures and it’s used by injection into the soil. And this happens before planting occurs in bare soil with plastic tarp rolled out over the land afterwards.

Methyl iodide has been touted as the best replacement for methyl bromide, another chemical soil fumigant, which has been in use as pesticide in the U.S. since the 1960s. But it was discovered that methyl bromide causes ozone depletion. In 2005, the U.S. phased out use of the chemical completely, except for a couple critical use exemptions.

The government turned to methyl iodide as a replacement because it doesn’t cause ozone damage. But Kegley and the Pesticide Action Network argue that it’s a difficult chemical to use with any certainty of safety.

KEGLEY: ...in fact, impossible to use with any certainty of safety. The people at greatest risk are those that are not necessarily involved with the application, because the people involved with the application are supposed to be wearing respiratory protection. But workers in adjacent fields or at adjacent businesses, and residents who live in particular areas in California – strawberry growing areas, where this pesticide is likely to be used (it’s one of the main crops it could be used on) – people who live a quarter to a half a mile of those fields are going to be at risk.

Kegley isn’t aware of a good alternative to methyl iodide. Instead, she advocates for farmers to stop relying on pesticides altogether.

KEGLEY: Organic farms do grow these crops without fumigation. And they way they do it is by first rotating the crops and not planting the same crop in the same place all the time. But also, by utilizing beneficial organisms in the soil. They are not silver bullets like methyl bromide. But they’re also not killing and hurting the other organisms, like the animals that live around the fields as well as the humans.

Don’t expect to see methyl iodide available for purchase at your local Home Depot. Untrained farm workers won’t have access to it, and anyone who does must undergo extensive safety training, licensing, and receive permits from their county specific to the site where the pesticide would be used.

For Crosscurrents, I’m Max Jacobs.

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