Study to measure pesticides near fields

YAKIMA – Monitoring stations have been set up at some central Washington orchards to measure whether pesticide sprays are drifting toward homes or schools.

Growers from Wenatchee to the Tri-Cities have agreed to allow the air around their orchards to be sampled, under the pilot program that started in early March. They have not been publicly identified and the sites are kept secret so that no one can tamper with the equipment or compromise the collection of data.

State lawmakers approved more than $1 million for the monitoring plus a study by the Washington Tree Fruit Research Commission in Wenatchee to find ways to reduce the amount of certain pesticides used on fruit trees.

Pesticide use has been a politically and emotionally charged debate among growers and farmworker advocates.

Growers fear the goal of the program may be to restrict their use of pesticides before alternatives can be developed, jeopardizing the state’s $6 billion tree-fruit industry.

Jim McFerson, manager of the Wenatchee-based Tree Fruit Research Commission, said growers will cooperate as long as the results aren’t used to punish the industry.

“If we’re put out of business, the game’s off,” McFerson said.

Even farmworker advocates aren’t completely comfortable with the design of the program. Carol Dansereau, executive director of the Seattle-based Farm Worker Pesticide Project, is concerned that because orchard owners know they are being monitored, they may be tempted to instruct their pesticide applicators to alter their spraying.

“My instinct is that this is problematic,” Dansereau said.

Richard Fenske, a University of Washington scientist, is leading the study for the state Department of Health. Fenske acknowledges that growers are wary of the study, but he said it can’t be done without their cooperation. Adding growers to his technical advisory committee has helped, he said.

“There was apprehension about air monitoring and I can understand that,” Fenske said. “So having people that growers know and trust review what we’re doing has helped avoid that acrimony.”

The monitoring is for a chemical called Chlorpyrifos, which is used by apple growers in the spring to protect trees before they bud. It has been banned for use indoors because of a health risk to children. Until 2002, the chemical was used in pet collars and as a bug killer in homes under the brand name Dursban.

In the field, if a worker is accidentally overexposed to the chemical, known as Lorsban as an agricultural brand, the effects are well documented. Symptoms range from dizziness and difficulty breathing to paralysis.

However, the risks of chronic, low-level exposure haven’t been definitively studied.

The results of the study will be presented to the 2009 Legislature. Fenske has cautioned that whatever the numbers show, they won’t be definitive.