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Nature 01358.txt

Scientists fume over California's pesticide plans: Nature Newschemists and activists encountered another setback in their battle to see methyl iodide banned from agricultural use last week, when the state of California proposed its approval. The state would require further, stringent regulations on the use of the soil fumigant, going far beyond the federal rules that allow for its use in other states. But Robert Bergman, a chemist at the University of California, Berkeley, who cosigned a 2007 letter of protest against the use of the fumigant, says that he is disappointed still greatly. The proposal is open to comment until 14 june after which California will make a firm decision. Methyl iodide is a replacement for methyl bromide, a pesticide that is known to contribute to depletion of the ozone layer and is being phased out under the Montreal Protocol on ozone-depleting substances. Methyl iodide is an effective pesticide and ozone-friendly, but it is known a mutagen, and it could cause cancer, nerve damage or fetal-development problems among workers and people living near fumigated fields. California is a major of purchaser of soil fumigants, which are used largely for growing strawberries and tomatoes. The state has been deliberating over methyl iodide for a year weighing up different safety evaluations. The US Environmental protection agency (EPA) approved the fumigant in October 2007, finding it safe for use. But a report by the California Department of Pesticide Regulation (DPR) concluded in 2009 that the compound posed significant health risks. The DPR commissioned an independent review, led by chemist John Froines, to settle the debate (see'Strawberry pesticide leaves sour taste').'The review sided with the assessment of the California DPR, saying in its 5 february reviewreport. pdf>report that in every instance where the DPR findings differed from the US EPA risk assessment for methyl iodide, this was attributable to a more insightful and scientifically rigorous approach having been undertaken by the DPR. It concluded that adequate control of human exposure would be difficult, if not impossible, and any anticipated scenario for â Â use of this agent would result in exposures to a large number of the public and thus would have a significant adverse impact on the public health. This led the nonprofit environmental law firm Earthjustice based in Oakland, California, to file a petition to the EPA, asking the agency to cancel its national registration of methyl iodide. Nevertheless, the DPR decided on 30 april that further restrictions would make methyl iodide safe enough for use. These include requiring site-specific licences, limiting exposure for workers and people living nearby to one-half and one-fifth, respectively, of the EPA's regulatory target levels, increasing buffer zones, and limiting the rate and extent to which the fumigant can be used. The extra, health-protective use restrictions we are proposing â Â are much stricter than those imposed anywhere else in the United states said DPR director Maryann Warmerdam in a written statement on 30 april. But the measures have done little to quell the fears of opponents. I am astounded that the California DPR in making this decision has ignored more or less an expert outside review, says Roald Hoffmann, a Nobel-prize-winning chemist at Cornell University in Ithaca, New york, who cosigned the 2007 protest letter with Bergman. The regulations assume that everything's going to go right, says Ted Schettler, science director of the Science and Environmental Health Network in Ann arbor, Michigan, and another protester against the use of the chemical. You have to have a lot of faith that there won't be accidents. There's not a lot of wiggle room for error with a compound like this. There are non-chemical alternatives to soil fumigants including planting strawberries alongside mustard or broccoli, which release chemicals that deter insects but these can be expensive or difficult to implement. The economic interests of farmers and pesticide manufacturers affect these decisions as much as science reports, says Schettler. There's probably no better example than pesticide regulation where you see strong interests attempt to affect policy. The DPR, however, has defended its decision to move forward with allowing the fumigant. The review members are experts in assessing pesticide risks not in regulatory risk management that leads to decisions on registration, the DPR said in a statement to Nature. Risk management is a distinct process of weighing scientific and other factors. The EPA is due to review its approval of methyl iodide in 2013. The chemical is registered already for use in 48 states. The agency does not have figures on how much methyl iodide is being used at present, press officer Dale Kemery told Nature in September. Our understanding is that there have been no reports of adverse health effects, he said.

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