Tuesday, June 6, 2006 • Ag commissioner responds to pesticide protesters

Before pesticide spraying begins to protect residents from contracting West Nile Virus from mosquitoes, Lassen County Agriculture Commissioner Ken Smith will have to get approval from the Lassen County Board of Supervisors.

Smith responded to five residents who complained about the possible health consequences of pesticide spraying to kill mosquitoes infected with West Nile Virus at the Tuesday, May 23 Board of Supervisors meeting.

Though there’s only been one human case of WNV in Lassen County in 2004, state WNV data show surrounding counties had numerous cases in 2005, including 25 in Butte County, four in Tehama County, and one in Shasta County.

Smith issued a press release last week saying his plan to control mosquitoes is an integrated control program and a multi-method approach using several strategies and “as a last resort, application of adult mosquito control materials only after pre-notification of the public.”

“Citizen prevention is the basic method of control,” Smith wrote. “It involves the exclusion of mosquito breeding habitat from residences and other critical areas and methods of personal protection from adult mosquitoes.”

He will continue to distribute information about how to limit mosquito breeding grounds around homes.

County staff, with help from the California Department of Health Services, continues to survey and collect species of birds especially prone to West Nile, including blackbirds, crows and magpies. Finding dead birds “is an indicator of the presence of West Nile Virus,” Smith wrote.

The ag staff will also continue to sample standing water for mosquito larva and trap adult mosquitoes to determine the species present and their numbers. DHS will analyze the results and recommend either adult or larva treatments.

If DHS recommends larva treatment, Smith‘s staff will apply several mosquito growth regulators and biological control materials to sources of standing water, storm drains and other areas where mosquitoes breed. The ag department is also developing a mosquito fish distribution program.

If trapping reveals a critical number of WNV mosquitoes, DHS may recommend adult mosquito treatment. Before any pesticides are used, Smith’s staff will notify those who have registered for a notification of treatment and/or requested no spraying at their homes. To get on the no spray or treatment notification lists, call the ag department.

If spraying is planned, Smith’s staff will notify the public at least 24 hours before treatment begins through radio, billboard message, the office answering machine, the county website and any other available effective means.

Information will include areas to be treated, the time of treatment and a copy of the pre-treatment pesticide risk reduction recommendations for home, property, children and pets.

Spraying for adult mosquitoes will begin after dusk and end before dawn. Adulticides will be applied using a fogger at ultra-low volume of only the least toxic mix and the lowest effective rate.

“By law, any and all pesticides used in California must be registered with the California Environmental Protection Agency, Department of Pesticide Regulation,” Smith’s press release said. “All of the control materials that will be used are registered in California. After treatment, county staff will conduct follow-up sampling and monitoring.”

Smith will seek approval from the Board of Supervisors for treatment of nuisance mosquitoes before large events like the county fair, it said.

The press release said the treatment program is “consistent with vector control programs throughout California and the nation” and is based on “accepted scientific data.”

Pesticide risk reduction recommendations for home, property, children and pets
If spraying of adulticides for mosquitoes becomes necessary, the amounts planned for spraying pose a relatively low risk to people and pets.

However, the Lassen County Department of Agriculture recommends that all individuals take the following precautions to avoid and reduce the risk of direct exposure and reaction to contact with pesticides:

• Some individuals may be sensitive to pesticides. Persons with asthma or other respiratory conditions are especially encouraged to stay indoors during spraying to reduce the chance of aggravating their health conditions.
• Air conditioners may remain running. It is recommended to set the air conditioner vent to the closed position or choose the re-circulate function.
• Bring children’s toys, outdoor equipment and furniture, clothing and other items that you come in contact with outdoors indoors until after the spraying has been completed.
• If items mentioned above do become exposed to pesticides, it is recommended that they be washed with soap and water before any contact is made with them.
• Park all vehicles in the garage not in your driveway and keep all vehicle windows closed.
• Wash immediately, with soap and water, any skin or clothing that has been exposed to pesticides during spraying.

Anyone experiencing adverse reactions to pesticides as a result of mosquito spraying should seek immediate medical care or call your local poison control center at (800) 222-1222.

The onset of symptoms in milder exposures can occur anytime up to 12 hours later, but usually within four hours. Consequently, diagnosis of a suspected poisoning must also be rapid. It is imperative to be familiar with the signs and symptoms these types of pesticides cause.

Signs and symptoms associated with mild exposures to organophosphate and carbamate insecticides include:

• Headache, fatigue, dizziness, loss of appetite with nausea, stomach cramps and diarrhea;
• Blurred vision associated with excessive tearing;
• Contracted pupils of the eye;
• Excessive sweating and salivation;
• Slowed heartbeat, often fewer than 50 beats per minute;
• Rippling of surface muscles just under the skin.

These symptoms may be mistaken for those of flu, heat stroke or heat exhaustion or upset stomach.

Moderately severe organophosphate and carbamate insecticide poisoning cases exhibit all the signs and symptoms found in mild poisonings, but in addition, the victim:

• Is unable to walk;
• Often complains of chest discomfort and tightness;
• Exhibits marked constriction of the pupils;
• Exhibits muscle twitching;
• Has involuntary urination and bowel movement.

Severe poisonings are indicated by incontinence, unconsciousness and seizures.

The order in which these symptoms appear may vary, depending on how contact is made with the pesticide. If the product is swallowed, stomach and other abdominal manifestations commonly appear first; if it is absorbed through the skin, gastric and respiratory symptoms tend to appear at the same time.

Fortunately, good antidotes are available for victims of organophosphate or carbamate poisoning at emergency treatment centers, hospitals and many physician’s offices. As with all pesticide poisonings, time is extremely critical. If a pesticide is swallowed, obtain prompt medical treatment. If a dermal exposure has occurred, remove contaminated clothing, wash exposed skin and seek medical care.