Department of Pesticide Regulation’s own scientist decries fumigant methyl iodide registration

Science was “subverted” in the state Department of Pesticide Regulation’s approval of the strawberry fumigant methyl iodide, and its use is likely going to have a negative impact on public health.


Those strong words came not from opponents of methyl iodide, but from the lead scientist hired by the DPR to conduct an independent review of the controversial fumigant. 


During a hearing Tuesday before the California Assembly Committees on Health and Environmental Safety and Toxic Materials, that scientist, John Froines, testified “there is no safe level for methyl iodide.”


"It is painful for me personally and professionally to have to report the science was subverted in the DPR approval,” said Froines, a professor of chemical toxicology at the UCLA School of Public Health. 


The fumigant kills nematodes, weeds and disease in the soil, and was registered by the DPR for use on Dec. 1, 2010. The same properties that make it an efficient pesticide also make it a human health hazard, according to opponents.


DPR registered methyl iodide for use at exposure rates as much as 100 times higher than what Froines’ Scientific Review Committee recommended. Froines contends real-world conditions must be taken into account, and that DPR’s risk management calculations do not effectively do so. 


For example, the agency’s “utopian view” that respirators are 90 percent effective is at odds with the scientific panel’s assumption that they are only 50 percent effective, said Froines. 


In a 2010 letter, Froines wrote, “DPR has taken a highly appropriate public health protective approach throughout this assessment.” His change of heart comes after the agency took a “fanciful and even ludicrous” approach to mitigating methyl iodide’s effects on workers and rural residents. 


Citing concerns like wind-blown tarps or long days for field workers, Assembly Health Committee Chair Bill Monning said, “My concern is the gap between label conditions and real-world conditions.”


The president of the California Farm Bureau Federation said user error should not be presumed. “As an applicator, I put full trust in that label, and that label had to go through rigorous approval,” Paul Wenger said. “I trust the system to be working.” 


Scientists have challenged methyl iodide at each step of the regulatory process. In 2007, as EPA was preparing to register the fumigant federally, 54 scientists – among them five Nobel prize winners – submitted a letter decrying the chemical as too toxic for use. The chemical has carcinogenic and neurotoxic properties, and can cause fetal damage or death. 


Methyl iodide was developed as a replacement for methyl bromide, which is being phased out because of its ozone-depleting properties. Some California berry growers have permits for limited methyl bromide use through 2012, and pending applications for 2013. 


But as to alternatives, California Strawberry Commission Director of Public Policy Rick Tomlinson says a fumigant like methyl iodide is the only viable business option for growers besides subsidies. 


As of Feb. 22, no growers had applied to any county agriculture commissioners for application permits.


The $2.1 billion industry may be waiting for their season to approach – or to see if the controversy leads to DPR pulling the registration. California Rural Legal Assistance and the environmental group EarthJustice also filed suit against DPR, asking the court to order the approval to be rescinded.

DPR chief Mary Ann Warmerdam read a statement during the hearing saying registration “would not have been granted if we were not confident these products could be used safely.”