Methyl Iodide Controversy: Warning About Strawberry Field Chemical Ignored
09 Nov, 2010
The Department of Pesticide Regulation has set acceptable exposure levels for methyl iodide that are 120 times higher than recommended by its own scientists and an eight-person panel the department commissioned to peer-review its work.
The decision to increase exposure levels has caused a rift within the DPR, a little-known but powerful agency that oversees a major segment of the state’s multibillion-dollar farming industry. In interviews, all eight peer-review scientists said their warnings and scientific analysis of the health risks of methyl iodide appear to have been disregarded.
“I’ve never seen anything like this,” said Ron Melnick, a panel member and scientist at the National Institutes of Health, who has participated in similar assessments in the past. “Why have someone review a document when you’re just going to ignore it?”
Thousands of Californians live, work or play within a stone’s throw of the state’s strawberry fields. Thousands more do the hands-on field work that supplies supermarkets across the country, fueling a $2 billion industry.
Currently, most California strawberry growers rely on a fumigant called methyl bromide. But that chemical is being phased out under an international treaty because it damages the ozone layer.
Conventional strawberry growers have spent a decade looking for a viable alternative and have turned up only one: methyl iodide. Under the new regulation, farmers would use the chemical as a fumigant to sterilize the soil before the plants go in.
Lab tests involving rats and rabbits show methyl iodide can cause thyroid cancer and miscarriages. But scientists say methyl iodide is also a neurotoxin. Although this research is less well-developed, case studies of people who were accidentally exposed to methyl iodide show “chronic, irreversible brain damage,” according to John Froines, a chemist at UCLA who chaired the independent review panel.