Aerial Spraying Against West Nile Needs Debate
Attention-span test: You do remember ... please tell me you remember ... that they sprayed pesticide on you from airplanes last August. I am trying to find out if they plan to spray stuff on us again next summer. Apparently that will be up to the U.S. Centers for Disease Control and Prevention.
I had a good conversation last week with one of the lead CDC scientists who were here last summer and pushed local officials to use aerial spraying. More on that in a moment. Right off, I can tell you that nobody knows whether last summer's spraying did any good.
Nobody. Not yet. I know that you have heard different. Right after the spraying, local officials were tossing around numbers like "93 percent effective." Nah. That was based on a report from the CDC that even the CDC told me last week was "extremely preliminary." It will be next month at the earliest before the CDC will have any kind of report it's willing to stand by to tell us if the spraying worked.
County officials, meanwhile, continue to sell last summer's spraying as a big success. No officials here are even talking about risks to human life from pesticide exposure.
Even though scientists at the University of Texas recommended that pregnant women leave the county last summer to avoid getting doused, County Judge Clay Jenkins and Dallas Mayor Mike Rawlings decided they had no choice but to spray the county with some stuff called endocrine disruptors to combat West Nile disease. Endocrine disruptors attack the immune systems of insects.
The UT scientists say the disruptors attack the immune systems of unborn children too. Jenkins and Rawlings felt they had to roll out the spray planes because Dallas was beset by a serious epidemic. In the end the total death toll here from West Nile was 18.
By all accounts the CDC was early and aggressive in its role here last summer promoting the adoption of aerial spraying. Two CDC scientists in particular pushed local officials to spray from planes — research entomologist Janet McAllister and Robert S. Nasci, a Ph.D. specialist in mosquito-borne disease. Jenkins told me last week he is awaiting their advice on what to do next year. McAllister told me the report will not be finished before December.
Jenkins says he will base any decision about spraying next summer on that report. "Wherever the science leads, that's where I will go," he said.
At the end of last summer's spraying, McAllister and Nasci gave the county a preliminary report indicating the airplanes were a big success, knocking down 93 percent of the bad skeeters in places they bombed. But Dallas entomologist Gene Helmick-Richardson, an airplane skeptic, told me last week he considers the CDC's preliminary report "total bullshit," tossed off way too fast to reflect any serious analysis.
McAllister did not use the same term to describe her own report, but she did say last week, "It was extremely preliminary, because that was based on information we had gathered at the time, so that did not include final testing."
The issue is whether the airplanes really reduced West Nile in Dallas or simply sprayed at a time when the disease was already collapsing on its own because of seasonal cycles. Last week I sat in on a lecture by Dr. Wendy Chung, chief epidemiologist for Dallas County, in front of several hundred public health students at Brookhaven College. She gave them chapter and verse on the process leading up to the decision to spray.
I would have to say the general tenor of her presentation was triumphal, including a reference describing the decision by Jenkins, her boss, to call in the airplanes as "courageous." But when she was done, I asked her if the bombing had done any good.
She said, "The official report from the CDC, the analysis, is ongoing, and the final determination should be forthcoming, we hope. What it appears is that the aerial spraying was done at a time when the activity of West Nile mosquitoes had already started to be somewhat on a decline. So it's difficult to prove whether the spraying measures hastened the decline of West Nile activity in the area or not."
Yeah. I will take that as, "No clue, stay tuned."
I plan to stay tuned. Chung's hour-long lecture, with discourses on media support for the airplanes, a history of West Nile in Dallas and mentions of unspecified political controversy, included no discussion or mention at all of endocrine disruptors. I don't get how anybody can even do the math on this without at least trying first to find out what the risks are.
I know. I know. You're going to say to me, "What about the risk of death and injury from West Nile?" Of course. That's the biggest part of the math. But there is math to be done.
Dallas author Howard Garrett spoke to the Dallas County Commissioners Court last week and presented them with options for killing adult mosquitoes with spray from trucks and airplanes, using substances that do not contain endocrine disruptors. Garrett gave them printed materials with plenty of links and references to programs and experiments with these substances.
After that meeting, I spoke with Jenny Land, who is with a group called Concerned Citizens for Safer Mosquito Control. She said her group has assembled scientific papers and journal articles from places like Rutgers State University in New Jersey and Cornell University in New York strongly supporting what Garrett told the commissioners — that there are effective ways to kill and control mosquitoes without exposing human beings to endocrine disruptors.
When Garrett has spoken on this topic before, some officials have treated him as less than a serious authority, suggesting he may even have a conflict of interest based on his marketing of his own trademarked organic garden products. None of those products is related to aerial spraying for mosquitoes.
But, look, this kind of innuendo, fairly or not, can be turned just as easily against the government agency scientists who promote aerial spraying. Nasci, one of the CDC pair who came here and urged aerial spraying, is a past president of the American Mosquito Control Association. When I look at the AMCA web site, I can't help noticing that it's paid for by a lot of corporate "sustaining members," including Clarke Mosquito Control, the company that produces Duet, the stuff the planes sprayed on us last summer.
I am not even remotely suggesting that Nasci gets marching orders from Clarke. But think about it. It does tell you something, does it not, about the culture of the organization. I can guarantee you that Howard Garrett would never have a logo like that within 100 miles of his web page, because for his own reasons he wants to avoid ever being associated with Big Chem. For Nasci, not so much maybe.
But let's say somebody doesn't trust Garrett because he has his own agenda. What about the people at Rutgers and Cornell? Why would we ignore those resources when we're talking about such an important matter?
If Dallas were to convene some kind of colloquium, we would quickly find a plethora of respected mainstream scientists with hard evidence pointing to three crucial considerations: 1) The substances sprayed on us last summer may be ineffectual in their main mission of controlling West Nile; 2) the substances may pose serious collateral health risks to humans, especially children; 3) better, more effectual, less dangerous substances are readily available.
Each of those three is an argument, not a fact. We can assume there would be many good scientists who would bring us lots of good science to rebut each of those three points and prove something else.
McAllister of the CDC told me last week that there is ample research showing that, "the risk, especially in an epidemic, of getting the disease and the consequences of the disease are much greater than the risk of the exposure to the insecticide. There is a whole series of scientific papers that look at the risk and the safety of the insecticides that are used and how they are used.
"Yeah," she said, "you can say that these compounds are endocrine disruptors, but it depends on the dose and the exposure." She spoke of the anti-insecticide people as "alarmist."
So there is a good conversation to be had about these risks. But we are not having that conversation. Instead what's going on is a lot of behind-the-scenes maneuvering by proponents of aerial spraying in order to have some kind of mechanism already in place next spring so that the decision itself is removed from public debate and control. I asked Jenkins about it. He said neither he nor anyone else at the county is involved in such talks, but he conceded he was aware of "private interests" who may be.
I am working on the question of who those private interests may be. I found Jenkins pretty open about it. I just need some more time to confirm a few things.
In the meantime we should probably start with a basic assumption that West Nile is a genuine and difficult challenge for our region and that all of the people involved in the issue have as their basic guiding intention a sincere desire to protect human life. It's from there on out that things get complicated.
McAllister made a point that seemed especially germane. She said you can't do the math by looking at only one side of the equation — the effectiveness of the spray or the dangers posed by the insecticide. You have to balance each against the other. So far in our discussion, we have looked only at the mosquito-killing power of the spray, not at all at the risk from the pesticide. And the story we have been told about 93 percent effectiveness is not true. This is not a good time to cut off debate.
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