Spraying to Stop West Nile - Is It Safe?

Not trying to be obnoxious. This is not I-told-you-so. But I did told you so.

In a column published December 29, I did point out that North Texas was taking all kinds of wild chances with its water supply by refusing to adopt the type of strict safety measures in effect in the Great Lakes region and in Southern California to protect lakes and rivers from invasive zebra mussels.

When I told Jeff Alexander, a Michigan journalist with an award-winning book on the topic, what was going on here, he said, "To me that just seems like Russian roulette at the highest levels."

Jared Boggess


After that? Radio silence. Who cares? Not a peep from City Hall.

So we played Russian roulette. And we lost. A couple weeks ago a story in The Dallas Morning News reported that "Zebra mussels have invaded Lake Ray Roberts and are expected to wreak havoc on drinking water systems in Dallas, Denton — and eventually cities along the entire Trinity River system."

Havoc. That's a bad word when applied to massive public drinking water systems.

So I come back to you now on another topic — West Nile mosquito pesticide spraying. I am not here with a big screaming prediction of doom but with the suggestion that maybe we might want to think a little bit about what we're doing, instead of ignoring possible perils the way we did with zebra mussels.

I asked city of Dallas spokesperson Frank Librio what research the city has done on possible biohazards associated with the chemical compound it is now spraying throughout our neighborhoods at night to combat West Nile. I asked because I was aware that both the U.S. Environmental Protection Agency and the California Department of Pesticide Regulation have just come out with much tougher restrictions.

Librio told me he would check with the city staff people involved. After several days, he emailed me back: "The product is considered safe when used according to manufacturer's label."

They read the label. Their research consisted of going into the chemical store like some dude off the street, picking up a bottle of the stuff and saying, "Yup, looks pretty good."

There's a big problem with that. Dallas sprays a compound called Aqualuer 20-20, whose active ingredient is a chemical called permethrin, a member of the pyrethroid family of compounds. If permethrin were being sprayed by anybody but a public health authority, extremely strict controls on its application would apply. No one else would be allowed to drive down a street and spray this stuff indiscriminately into the air.

Public health authorities, however, are exempt from those restrictions. I spoke to Lea Brooks at the California Department of Pesticide Regulation, because their new restrictions on Aqualuer 20-20, put in effect just a week ago, are even tougher than the new EPA standards.

But Brooks told me that in California, as here, public health authorities get a pass from those restrictions. "This product is allowed under an exemption as a public safety issue," she said. "I know in California and probably in other states the health authorities here have a lot of authority when it comes to protecting the public health."

I asked if in their review her agency had come up with any evidence that spraying permethrin into the air in the way it's done as mosquito control actually does any good at cutting back West Nile infections in human beings. She said pesticide manufacturers supply the state with their own "efficacy data."

That was really what I wanted to find out from Librio. It's two questions. Do you know what the biohazards are? Do you have proof that it's worth our while to run those risks?

The reason to ask those questions is a growing body of negative opinion on both points.

Sheldon Krimsky, a professor of urban and environmental policy planning at Tufts University in Massachusetts and author of several books dealing with public policy and environmental risk, was one of a panel of experts, including people at Harvard and MIT, convened to study pyrethroids after the city of Cambridge, Massachusetts, began spraying them in 2000. Cambridge has not sprayed since that panel issued its report, even though West Nile has been found there.

Krimsky says a principal reason the panel recommended against spraying pyrethroids was that the known risks were not outweighed by any evidence that spraying did any good. "There was no evidence that the aerial spraying really reduced the mosquito population," he told me.

In 2008, a student at Yale working on a combined master's degree in public health and business authored a study, later reported in the Yale School of Public Health newsletter, which found that pyrethroid spraying in Sacramento County, California, in 2005 had reduced the incidence of West Nile virus found in humans. The author claimed that his study had been "peer-reviewed" by experts in the field.

But that same year the Pesticide Watch Education Fund published its own knock-down of the Yale student's study, reporting that they had made open-records demands for underlying data and for the claimed peer reviews of the study and had received nothing in response. In the meantime, they showed in their own article that the Yale grad student had started measuring the incidence of West Nile in California after that year's West Nile season had begun its natural seasonal decline. He then gave credit for the seasonal decline to the spraying.

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We now have not only a confession from Zachary Thompson, DCHHS of his criminal behavior these past two years in regards to ordering the spraying of his fellow citizens with Chemical Agents and Poisons; but a "Terrorist Threat" to continue to do so; even when he receives a refusal from ANYONE in the DCHHS jurisdiction;. In essence he has threatened more than 2 million people.

We will make this communication available if we have an email address to forward the information to.


We have over whelming evidence that this practice has no impact on the spread of West Nile Virus simply because the Virus is already endemic in the wild bird population. Contact us at themindfuldissenters@outlook.com and we will forward  the very arrogant letter from DCHHS/ and another attachment that will offer a solution to those who wish to "dissent to being sprayed"..

"When you stand you will not stand alone"


BATS EAT MOSQUITOS! put up a bat house, attract bats to your yard or community. Bats eat over 1000 flying insects in a single evening. Lone Star Woodcraft makes certified cedar bat houses.

Ian Gregory
Ian Gregory

There's almost an airforce of planes in Florida dedicated to mosquito control, has anybody in North Texas considered taking advice from the folks down there?


...over the years, it has appeared that "government" is more concerned about looking good than it is about actually serving and protecting the public...so I don't trust 'em...I guarantee one thing...I won't be inhaling around any city machine that looks like it might be spraying for anything...as a matter of fact, I don't plan to be found anywhere near such a machine...


"you would need to spray during the day when those mosquitoes are flying, not at night when the big fat belly-full mosquitoes are safe under their leaves of grass."


Does that make sense?  Mosquitoes are flying after dark.  You are more likely to receive a mosquito bite at night than in the middle of a 100+ degree sunny day.  At least in North Texas.


A far more effective program of mosquito abatement would be to arm our city council members with flyswatters and haz-mat suits and send them out at dawn and dusk to kill the little buggers individually.


As an added bonus, we'd actually get some productivity out of our city council.

Myrna.Minkoff-Katz topcommenter

There is, in addition to the West Nile crisis, an incipient epidemic of intestinal illness caused by  cryptosporidium hitting the DFW area.


Cassandra wasn't listened to, either.


You raise some good points, but you are forgetting something VERY IMPORTANT to our 'leaders';


Rule #1 In any sort of a crisis or public alarm raising incident, you have to be seen as "DOING SOMETHING!", regardless of the effectiveness or efficiency of that "something".

JimSX topcommenter

 @cynicaloldbastard I think you're right. I got this wrong, sort of. The blood-gravid adults are actually protected under plants at night, so night spraying doesn't get them, but day spraying wouldn't., either. Maybe. They sure fly during the day at my place.  But the real answer is to go after larvae.