UC Blog
UCLA study links pesticide exposure to Parkinson's disease
UCLA scientists have found that people whose workplaces were close to fields sprayed with the pesticides ziram, maneb and paraquat -- not just those who live nearby -- are at higher risk of developing Parkinson's disease, reported the Los Angeles Times.
The disease has been reported to occur at high rates among farmers and in rural populations, contributing to the hypothesis that agricultural pesticides may be partially responsible, said a UCLA news release about the study.
The researchers discovered that combined exposure to the three pesticides increased the risk of Parkinson's disease threefold, while combined exposure to ziram and paraquat alone was associated with an 80 percent increase in risk. The results appear in the current online edition of the European Journal of Epidemiology.
Scientists already knew that in animal models and cell cultures, such pesticides trigger a neurodegenerative process that leads to Parkinson's, a disorder of the central nervous system that impairs motor skills, speech and other functions and for which there is no cure.
In the past, data on human exposure had been unavailable, largely because it was too hard to measure an individual's environmental exposure to any specific pesticide.
"This stuff drifts," said Dr. Beate Ritz, senior author and a professor of epidemiology at the UCLA School of Public Health. "It's borne by the wind and can wind up on plants and animals, float into open doorways or kitchen windows — up to several hundred meters from the fields."
Ritz and her colleagues developed a geographic information system-based tool that estimates human exposure to pesticides applied to agricultural crops, according to the distance from fields on which pesticides are sprayed. This GIS tool combined land-use maps and pesticide-use reporting data from the state of California.
From 1998 to 2007, the researchers enrolled 362 people with Parkinson's and 341 controls living in the Central Valley, then obtained historical occupational and residential addresses from all the study participants. Employing their geographic information system model, they estimated ambient exposures to the pesticides ziram, maneb and paraquat, at work and home, from 1974 to 1999.
The data "suggests that the critical window of exposure to toxicants may have occurred years before the onset of motor symptoms, when a diagnosis of Parkinson's is made," the news release said.
'No fever' policy at California horse shows
In light of the recent equine herpesvirus outbreak in horses, the UC Davis School of Veterinary Medicine recommends that horse show organizers impose a "no fever" policy for horses attending their events.
The school acknowledges that most horses with a fever don't have equine herpesvirus, but the policy should be enforced for biosecurity reasons.
Equine herpesvirus is a highly contagious airborne virus that has killed or led to the euthanization of at least seven horses this month, the Los Angeles Times reported. The outbreak has been traced to an event in Ogden, Utah, between April 18 and May 3, and an event in Bakersfield on May 13. It has spread to nine states, including New Mexico, Oregon and Washington.
The California Department of Food and Agriculture announced yesterday that 12 California counties have positive confirmed cases of equine herpesvirus.
- One case each in Amador, Los Angeles, Marin, Napa, Plumas, Sacramento, Shasta and Ventura counties
- Two cases each in Glenn and Kern counties
- Three cases each in Placer and Stanislaus counties
Seven of the infected horses displayed severe neurological symptoms, including one whose condition grew so grave that he had to be put down. The 17 others are under a state-ordered quarantine and are being treated by private veterinarians, CDFA public affairs director Steve Lyle told the LA Times.
Lyle said the department was not ordering or recommending that horse events in the state be canceled, though "that could change at some point."
Horses with a 102-degree fever or higher may not participant in horse shows.
Calaveras County considers consolidation
The Calaveras County Board of Supervisors expressed some concerns on Tuesday about plans to reorganize the UC Cooperative Extension service on a regional basis, reported the Calaveras Enterprise. The board took no action, but the issue is expected to be brought forward for a vote in June.
Under the plan, UC Cooperative Extension in Calaveras, El Dorado and Amador counties would be consolidated. Satellite offices would be maintained in each county and the main office located in the El Dorado County community of Placerville.
“The UC system has been hammered with budget cuts, we know you’re getting hammered with budget cuts and we’re looking at ways to keep the programs that we have,” the director of ANR Strategic Advocacy and UC-County Partnerships Don Klingborg told the board. By making administration more efficient, the consolidation could save each county about 10 percent of their contribution to the program.
Supervisor Steve Wilensky took issue with the Placerville location, the newspaper reported.
“I’m not interested in an unequal partnership,” Wilensky was quoted.
The board was also concerned with the possible job loss for clerical staff.
Exotic stink bug threatens nearly nationwide damage
"All that we do know for certain is that a tremendously large population went into overwintering in fall 2010. So, if they survived, there could be a very large population emerging in the spring," the story quoted Tracy Leskey, a research entomologist at the U.S. Agriculture Department's Appalachian Fruit Research Station in Kearneysville, W.Va.
The stink bug will feed on almost anything, including cherries, tomatoes, grapes, lima beans, soybeans, green peppers, apples and peaches. When it feeds, it leaves behind an ugly spot that renders the fruit or vegetable unmarketable.
UC Cooperative Extension farm advisor Stephen Vasquez and viticulture specialist Matt Fidelibus warned of the new pest's potential to harm California grape crops in a post to their new Viticulture blog. They wrote that damage can be substantial when BMSB populations are not identified early and managed appropriately. Growers and wineries are also concerned that the “stink” from any bugs accidentally crushed in wine or juice grapes could taint the product with off flavors.
"One might define this thing as the bug from hell," U.S. Congressman Roscoe Bartlett told the Chron. "If I was a mad scientist doing gene splicing and putting together a bug that would really be nasty and I was turning it loose on my enemy, I probably couldn't do a better job."
The Chronicle said the best hope for farmers that have brown marmorated stink bugs is the insecticide dinotefuran, the active ingredient in the commercial products Venom and Scorpion. The chemical compound is labeled by the Environmental Protection Agency for use on vegetables, grapes and cotton, but not in orchards, as it is in Japan and other Asian countries.
More information about the BMSB and current research is available in a streamed PowerPoint presentation by USDA's Lesky posted on the web.
Methyl iodide applied on a Sanger farm
Even as controversy continues to swirl about the use of methyl iodide in agriculture, the fumigant was used for the first time in California when it was applied to a one-acre Sanger chile pepper farm this month, the Fresno Bee reported.
The story, written by Robert Rodriguez, said the farm, northwest of DeWolf and North avenues, is owned by Sarkis Sarabian.
The California Department of Pesticide Regulation approved the use of methyl iodide in December and created restrictions that include buffer zones, special training and tarps to contain the chemical.
"These are the strictest conditions in the nation," Fresno agricultural commissioner Carol Hafner was quoted in the story. "And we made sure they were followed. Everything went fine."
The article generated numerous outraged comments.
"Our government is now in the business of feeding poison to people and telling us that it's good for us," said one.
"It's the biggest disgrace of our time. Killing a nation as well as the rest of the world with this garbage. Feeding people empty foods with little nutritional value. Nice to fatten your wallet while the world withers to dust," wrote another.
UC Riverside emeritus professor Jim Sims also posted a comment on the Fresno Bee website, pointing readers to a DPR document that explains DPR's decision to register methyl iodide. Sims is the patent-holder for methyl iodide as a soil fumigant. He spent more than 30 years researching the chemical in the lab and in the field.
Sims recently penned the "pro" view of a "point/counter point" op-ed piece about methyl iodide for The Salinas Californian.
He said that:
- Methyl iodide doesn't make the cancer-causing-chemical lists of the world's leading agencies for cancer research.
- Methyl iodide is a naturally occurring compound present in the sea and air and on land.
- Research demonstrates that methyl iodide does not get into groundwater supplies.
- Methyl iodide has been used on thousands of acres in the United States without a single negative impact to human health or the environment.
The "con" view was written by Pesticide Watch Education Fund director Paul S. Towers.
He said that:
- Methyl iodide is so reliably carcinogenic that it is used in the lab to create cancer cells.
- Washington state denied the use of methyl iodide based on California's scientific review.
For more on methyl iodide, see Hanson's December 2010 blog post.