Fifty-four scientists warned against it. The Farmworker Association of Florida opposed it being registered for use in Florida. The state of California is in a heated debate over approving it. Now, results of air monitoring and groundwater testing in our state are sounding the alarm that are being heard from Florida to California. It is a toxic fumigant pesticide called methyl iodide. And, it is being used on strawberry fields in Florida.
The Florida Department of Agriculture approved methyl iodide for use in Florida in 2008. The Farmworker Association of Florida initiated a letter writing campaign to oppose the registration of this fumigant in our state. While the campaign was unsuccessful in stopping the approval of methyl iodide, it was successful in that Florida adopted stricter regulations than those proposed by the EPA. Part of those regulations included air and groundwater monitoring by the manufacturer of the pesticide. Arysta LifeScience—methyl iodide manufacturer and the largest privately held pesticide company in the world—was obligated to conduct air and groundwater monitoring after field applications in the state. Consultants hired by Arysta to conduct the monitoring recently revealed in their report that iodide, a breakdown product of the pesticide, was found in Florida groundwater near a field fumigated in 2008 and 2009 at levels that ranged from 0.12 to 0.15 mg/L, substantially above typical levels of iodide in fresh water or sea water. The results cast serious doubt on growers’ ability to use methyl iodide without contaminating groundwater.
The levels of iodide found in Florida groundwater exceeded levels considered safe for children. Children drinking water with this level of iodide contamination could receive 1.2 times the tolerable upper limit of iodide exposure defined by the Centers for Disease Control and the National Academy of Sciences of 0.20 mg/day. Excess iodide exposure is associated with pre- and post-natal developmental toxicity and autoimmune thyroid disease, and possibly impairment of childhood cognition and postpartum depression. Healthy children with no iodine deficiency are assumed to be getting the recommended daily intake (RDI) amount in their diets on a daily basis. Any added iodide from contaminated groundwater would be on top of normal dietary iodide and would result in exceeding the 0.20 mg/day standard.
The report also indicates that the air near fumigated fields contains methyl iodide at levels posing health risks to community residents and farmworkers in nearby fields. Air monitoring results from Florida showed an average air concentration of methyl iodide at a 30-foot buffer boundary during the first 24 hours after application to be 9 parts per billion (ppb), or 30 times higher than the 0.3 ppb concentration deemed to be marginally acceptable by the Scientific Review Committee, a peer–review committee of independent scientists who reviewed California’s Department of Pesticide Regulation’s risk assessment of methyl iodide. The maximum air concentration measured between 4 and 8 hours after application was 37.5 ppb, or 125 times the 0.3ppb level that these scientists recommend as a maximum exposure limit to prevent fetal death.
“These results confirm that farmworkers’ and their families’ health is at risk from the use of this dangerous pesticide in Florida. Even with tight restrictions, these test results show that methyl iodide is impacting air and groundwater – the very air that farmworkers breathe and the well water that is their source of drinking water. Worker health is first and foremost our priority and methyl iodide has been proven to be too harmful for Florida agriculture,” said Jeannie Economos, Health and Safety Project Coordinator for the Farmworker Association of Florida.
“These methyl iodide air levels were found even though the field was covered with the special type of tarp (called Virtually Impermeable Film ) that DPR is counting on to control exposures ,” observed Anne Katten, Pesticide and Work Safety Specialist at California Rural Legal Assistance Foundation. “While larger buffers would be required in California, the Florida monitoring also found levels over 2 ppb (about 8-fold higher than the 0.3 ppb level scientists deemed marginally safe) after buffer zones would have expired.”
The Arysta-funded air and water monitoring report from Florida can be downloaded at http://dl.dropbox.com/u/491851/IR1_MIDAS_004-11437-00.pdf.