Amid widespread public fear Monday night, Sacramento County's top health officials conducted the area's first aerial spraying to kill mosquitoes and try to rein in West Nile virus.
As night fell at McClellan Park, two twin-engine planes began spraying Sacramento County north of the American River. One plane was grounded for an hour with software problems, but 71,000 acres were expected to have been covered by early morning.
Mosquito-control officials said the spray is safe for people, animals and fish, as well as landscapes and waterways, because it is being applied in minuscule droplets that should dissipate before touching the ground, but not before wiping out mosquitoes. They noted the chemical is approved by state and federal environmental agencies for use on food crops at higher levels.
Many residents, however, were concerned about the spraying because the chemical being used includes an ingredient that the federal government has listed as a possible carcinogen.
"We do understand this is unprecedented," said David Brown, manager of Sacramento-Yolo Mosquito and Vector Control District. "We have a West Nile virus epidemic at this point."
Brown said later that the aerial attack was "carefully thought out, not a knee-jerk reaction."
"The agency has been working on this for more than two years," he said.
The spraying took place on a day marked by fear that reached panic levels in some places, and the news that two more potential cases of the virus are being investigated in Sacramento County.
Throughout the day, people from across the region flooded the mosquito control district and local media with questions about the safety of all that is dear to them: newborn babies, elderly family members, kittens and koi fish, garden tomatoes, backyard pools and the paint on their cars.
Several groups of residents called a news conference and at one point threatened to seek a court injunction, saying the chemicals pose health dangers and should not be sprayed overhead.
At a separate news conference, county officials insisted the insecticide is safe. Similar spraying programs have been used routinely in cities across America, they said, including Miami, Houston and New York.
Spraying will be repeated tonight in the same northern areas of the county, and district officials will know by noon whether they spray again Wednesday. People are being advised to once again remain in their homes and close windows and doors from about 8 p.m. until midnight.
The product being used, EverGreen Crop Protection EC 60-6, lists on its label toxic ingredients such as pyrethrins, insecticides extracted from chrysanthemum flowers widely used in household and garden products, and piperonyl butoxide, or PBO, a chemical that inhibits insects' ability to detoxify pyrethrins.
Some critics of aerial spraying said they are more concerned about PBO because the U.S. Environmental Protection Agency considers it a "possible" cancer-causing agent that targets the liver. PBO makes up 60 percent of the insecticide, compared with 6 percent pyrethrins.
In the small amounts that will be used, the chemicals are far less hazardous than a continued upswing in West Nile, said Dr. Glennah Trochet, Sacramento County's public health officer. In some areas north of the American River, one in 10 mosquitoes recently were found to be infected.
The disease has made a steady march across the nation and has begun escalating in California, with three deaths reported to date in 2005.
For most victims, the mosquito-borne virus passes with no noticeable symptoms, but roughly one in 150 contract more serious versions that can cause paralysis and other neurological problems. A small proportion of those end in death.
Although no deaths have occurred in Sacramento County, the county counted 22 confirmed cases of human infection as of Monday, with additional reports being investigated, Trochet said.
"We are really at the brink of an explosion," she said. The full reach of the disease is difficult to measure because so few feel symptoms, though blood donations offer a glimpse: Since July 15, a little more than one donor of every 1,000 in the greater Sacramento region has been found with West Nile virus, according to Dr. Chris Gresens, medical director of clinical services for BloodSource.
Over the next two days, the vector control district will monitor mosquito populations and determine whether a third spraying in the north area will be needed Wednesday night, Brown said.
A similar string of nighttime applications in the south county could come as early as Thursday evening, depending on mosquito monitoring results.
During the spraying, the insecticide is atomized and its droplets are so tiny that they can kill a mosquito on contact, but not a larger insect, Brown said.
The dosage is so small it is not expected to collect in measurable amounts in waterways or land areas, officials said, although their assurances were disputed by representatives of organic gardening and other groups.
The vector control district and independent researchers plan to track what actually happens on the ground, using sensitive slides, films or other devices to monitor six to 20 sites, Brown said.
Walter Boyce, director of the University of California, Davis, Center for Wildlife Health, will monitor effects on "nontarget" insects like beetles, earwigs and ladybugs. The center is studying West Nile's impact on the bird population.
The insects will be put in small containers under the path of the aerial spraying, so that the effects on other species can be understood, and the results will be shared quickly with county officials.
The potential for spray to drift into waterways, essentially ruled out by mosquito control officials, could form the basis of a legal challenge.
Aerial pesticide spraying that affects waterways is not allowed without a permit from state water-quality enforcement agencies, according to Craig Wilson, chief attorney for the State Water Resources Control Board. The mosquito district did not apply for a permit, he said, "so they must be taking the view that they will not be discharging into the waters of the United States."
That is the district's view, Brown said, but it was met with skepticism by organic gardening and chemical watchdog groups who attacked the work for being done without water regulators' OK.
There were other worries about potential risks for those below.
"We're really concerned," said Sacramento resident Bob O'Brien. "Is the solution worse than the problem?"
Shawn Harrison, who commercially farms about 10 acres in northern Sacramento County, wondered whether he could honestly sell his crops as pesticide-free after the spraying.
Brown said the unusual combination of heavy rains into mid-June, followed by a stretch of 100-degree-plus days, sent mosquito populations soaring.
"I would love to have given people a month's notice," Brown said. "I don't think anyone thought it would hit this hard, this fast, this early."
While the district believes that staying indoors during spraying would be prudent, it doesn't think any other precautions are necessary, he said.
Mo Zubeidi said he saw no need to worry as he sat reading a newspaper outside Java City at Loehmann's Plaza about 9:40 p.m., a few minutes after the spray planes took off.
Zubeidi was one of about 30 customers on Java City's patio.
"It's better than having West Nile virus," he said. "I believe them when they say they're doing this for the public good."
Others around the Sacramento region were more cautious.
Games at the Sacramento Softball Complex, near the Capital City Freeway and Watt Avenue, after 8:30 p.m. were canceled.
"The players were notified by phone this morning when we found out," said Chris Jackson, a site supervisor. She said there were no complaints. The complex usually closes about 11 p.m.
Next door, the Haggin Oaks Golf Complex closed the driving range, usually open 24 hours a day, at 8:30 p.m. "Even the rain didn't close us down; the mosquitoes did," said Angela Schulz, cashier at the range.
About the writer:
- The Bee's Deb Kollars can be reached at (916) 321-1090 or firstname.lastname@example.org. Bee staff writers Nancy Teichert, Chris Bowman, Edgar Sanchez and Cameron Jahn contributed to this report.