EPA Approves Iodomethane Pesticide Use Despite Scientists' Concerns

The Environmental Protection Agency has announced that it has approved a one-year registration of iodomethane (methyl iodide), a pesticide that is being touted as a substitute for methyl bromide, which is known to deplete ozone. Last month, 54 scientists sent the EPA a letter dissuading the Agency from approving the use of methyl iodide, which the scientists feel is too dangerous to be released into the environment.

The EPA sent a response letter to the group of scientists, many of whom are professors at some of the nation's most distinguished universities. In the response, the EPA assures that the new pesticide has undergone extensive testing and peer-review from Agency scientists and the independent Scientific Advisory Panel. The EPA has also stated in an Agency press release that iodomethane has gone through one of the "most thorough analyses ever conducted on a new pesticide." The testing concluded that iodomethane is an effective soil-fumigant and also meets the health and safety standards set by the EPA.

In September, 54 scientists, headed by Robert G. Bergman from the University of California at Berkeley and Roald Hoffman, a Nobel Laureate in Chemistry and a professor at Cornell University, sent a letter opposing the registration of iodomethane. In that letter, the group of scientists writes they are "perplexed that U.S. EPA would even consider the introduction of a chemical like methyl iodide into agricultural use. The Agency has spent a great deal of effort to reduce industrial toxic emissions from chemical manufacturing plants. It is astonishing then that the Office of Pesticide Programs is working to legalize broadcast releases of one of the more toxic chemicals used in manufacturing into the environment."

The letter to the EPA cautions that due to the water solubility of the chemical, the group of scientists are concerned that "broad use of this chemical in agriculture will guarantee substantial releases to air, surface waters and groundwater, and will result in exposures for many people. In addition to the potential for increased cancer incidence, U.S. EPA's own evaluation of the chemical also indicates that methyl iodide causes thyroid toxicity, permanent neurological damage, and fetal losses in experimental animals."

The group of scientists urges the EPA in very strong language to hold off on the registration of iodomethane, and if anything, to wait until a panel of scientists can adequately access the safety of the pesticide. Of those that signed the letter, there are three Nobel Laureates and 49 members of the National Academy of Sciences.

The EPA's response letter to the Professors Bergman and Hoffman delineated the EPA's testing standards for iodomethane. The EPA is basing the safety of the chemical's release as a pesticide on the "stringent use conditions" and buffers that will keep any levels that come into human contact low enough that the pesticide will not cause adverse effects.

According to the EPA, the buffer zones are specified on the product labels. These zones may be reduced depending on application rate and method, field size, the use of a tarp, and the type of soil. Iodomethane can be used as a pre-planting fumigant to control plant diseases, insects and weeds on strawberries, tomatoes, peppers, ornamental plants, turfs and lawns, trees and vines.

Source: Environmental Protection Agency