Is Dallas Getting Smarter in the Fight Against West Nile?
You get a lot of dumb and dumber news here, so I figure I owe it to you to mention when things might be trending the other way. It's just possible the county's efforts to control West Nile disease could be headed in that other uncustomary direction. Smarter. Believe it or not.
Last year was awful, we all know that. Nineteen people died. Dallas County had 173 cases of the paralyzing form of mosquito-borne West Nile disease and 225 cases of the form that causes brutal fevers. Tests caught 19 people who wanted to give blood but turned out to have the disease in their systems. The incidence rate per capita was more than twice the rate in the last major outbreak in 2006.
This year is upside down from that. So far we have had only four human cases of West Nile, two of each kind, and no deaths. But according to the County Health and Human Services Department, we have way more mosquitoes this year. Entomologists say this kind of up and down cycle for the disease is typical and predictable. We can expect a worse year soon.
Last year at the height of it, people felt they were under attack, and maybe it's understandable that some groups like the county medical society went a little daft on us. They have a lot of members who live in the heavy-lawn-irrigation district in the Park Cities and Preston Hollow gold coast, where the incidence was higher. So they were the ones calling for the Air Force to come carpet-bomb us with neurotoxins.
For whatever reasons, there was a lot of craziness in our response to the 2012 West Nile epidemic. Dallas County Judge Clay Jenkins was doing map and baton lectures about the spray planes like he was about to go save Private Ryan. Every time Dallas Mayor Mike Rawlings talked about mosquitoes he sounded like Winston Churchill (fight them on the tennis courts, fight them on the golf courses).
But the really crazy thing was the outcome, once there was time to go back and measure what really was accomplished by spraying toxic chemicals all over the city. A report by the U.S. Centers for Disease Control and Prevention, a big booster of the aerial campaign in the first place, insisted the aerial spray had had some kind of measurable positive effect, but the fine print in the report said the best effect they could gin up was well within the margin of error, and way down in the fine print was the fact that our mosquito population actually increased during the spraying.
Say what? Airplanes carpet-bombing us with mosquito poison, and we have more mosquitoes, not fewer? While the bulging-eyed gin-and-tonic crowd at the medical society were out waving their putters over their heads screaming for nukes, an informal ad hoc group of residents and activists was busy assembling research from all over the country to show that the ineffectiveness of the aerial campaign should not have surprised anybody.
As it turns out, spraying chemicals from airplanes to kill flying adult mosquitoes at night is dumb. One big problem: That's not when they fly. Other big problem: If they're not flying, the poison doesn't get to them.
Meanwhile, the poison companies typically add other ingredients to their spray called endocrine disruptors to shut down the endocrine and immune systems of insects. But the same stuff also affects the endocrine systems of human beings, at least temporarily. The endocrine system governs brain development in very young children. A Harvard scientist told the Dallas citizen group no research has been done on the effect of endocrine disruptors on human development. But a scientist at UT-Austin who works in a related field said there is cause for concern.
The way things go normally around here, whatever they did last year that was dumb they should be doing again this year only dumber, like maybe go to the hospitals and fog the maternity wards. But that may not be where we are headed this time.
For one thing, the citizen group, Concerned Citizens for Safer Control (CCSC), now gives high marks to County Judge Jenkins for actually listening to them once the panic attack was over, and they give especially high marks to Dallas County Health and Human Services Director Zachary Thompson, who they say has been receptive to their central argument. They want the county to use the neurotoxins only as a last resort and go after the mosquitoes with larvicides first. They say Thompson has at least been willing to listen to argument and look at data.
Jennifer Land of CCSC told me: "We've always appreciated Zach Thompson. We've met with him several times. I think he's in the hardest position. No matter what he does, nobody thinks it's right."
Land believes the larvicide-first policy is right. In the first place, larvae are usually easier to find than flying adults. But also, larvicides are so non-toxic to mammals that it's safe to put them in your dog's water bowl. (Experiment first by putting them in your neighbor's dog's water bowl.)
Two weeks ago, CCSC delivered a letter to local officials urging the larvicide-first approach, signed by 50 people including a pretty amazing array of the city's top chefs, several scientists, garden groups, food producers, clergy and concerned residents. It was a stunning show of support for CCSC's position. No politician could smack that letter back down on his or her desk and mutter, "Damn kooks."
The basic idea is simple: Go out before any infected mosquitoes are found, before the disease cycle ever gets going, and use a variety of tools — mosquito "dunk" tablets placed in standing water, backpack sprayers or even the same spray trucks used for the neurotoxins — and kill the larvae with the much safer larvicide, cutting off the breeding cycle before it can get going. If that doesn't work and infected mosquitoes start showing up in the traps, then maybe it's time for the neurotoxins.
The larvicide seems to work. One of the signers of the letter was Howard Garrett, the Dallas organic gardening expert who does a nationally syndicated radio show under the moniker "The Dirt Doctor." Garrett is also involved in commercial land management. He told me last week that the larvicide-first approach is already being used in Dallas by some major lawn-care companies. He told me of one big company that he said is using larvicide on 40 residential properties.
"They are having tremendous results," he said, "coming pretty close to totally eliminating the problem."
In turning from a policy of neurotoxins first to a policy of neurotoxins last, however, local officials face a hurdle. Last year when the gin-and-tonic putter-wavers were calling for air strikes, they had a major ally in the CDC, which gave strong support to the aerial campaign, the first in Dallas since 1966. While many local and regional vector control (skeeter killing) agencies around the country now treat adulticide toxins as a last resort and larvicides as the first, the CDC will not rank them that way.
Janet McAllister, a CDC entomologist in Fort Collins, Colorado, described CDC policy to me as geared to local conditions, to the science and to what's going on with the insects. "Our message," she said "has always been integrated mosquito management.
"That means you use the most appropriate methods to control the mosquitoes but you pick that method also keeping in mind that it's what you could afford to do and what is going to be least hazardous to people and to the environment."
That may sound even-handed, but it's not where people like the CCSC group want to wind up. If neurotoxins are considered a solution equally weighted with larvicide in a mosquito control strategy, then that leaves the door open for communities to wait for trouble and then go straight to the neurotoxins. In order to use larvicides effectively, a community needs to get out ahead of the disease and begin killing larvae long before there are human cases.
Thompson, the county health director, told me that he and other county officials are keeping their options open, sticking to the concept of an integrated approach based on conditions. But he sounded as if he is also giving serious attention to the idea of a larvicide-first and larvicide-early approach.
"I have talked to Jennifer Land, and they have some great ideas," he said. "I want to be very clear. I don't mince words. We are going to consider as part of our 2014 strategy looking at the larviciding scenario that they have mentioned. We are all on the same page on that, and we definitely take their information seriously."
So, look, I don't get all weepy about it here and start blowing my nose and stuff, but this is actually the second important instance I have encountered in recent months in which local officials are dealing attentively and respectfully with environmentalist-leaning citizen action groups. The other one was about saving an important archeological site from the trampling hooves of rich horse-club people. I think they also drink gin-and-tonics and wave putters or something that looks like a putter in the air while they ride, but we can look into that another day.
The point now is that citizen outcry and a public demand for safer, saner use of pesticides may be on the verge of producing tangible results in local public policy. That's a huge deal in terms of chemical safety and health. It could be an even bigger deal in terms of political culture. If this trend toward a more enlightened local politics continues, I'm going to be parking cars for a living.
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