Every summer since 1980, Columbus has sprayed insecticides from truck-mounted foggers to kill mosquitoes. I never thought about it until a few years ago when I learned that property owners could ask that their houses not be sprayed.

My wife and I immediately opted out of having our Clintonville home sprayed and have every year since. This year, I heard confusing information coming out of Columbus Public Health, the agency responsible for mosquito control. I also heard from a neighbor that she had been sprayed while riding her bike to work. After more investigation, I became concerned about how mosquito control is performed in Columbus.

First, some background: Mosquitoes are a part of the ecosystem. They’re an annoyance that I’ve tolerated with the aid of repellent and citronella candles. And I figured that the dragonflies, bats and birds would keep them in check, just as they’ve done for thousands of years.

With the arrival of the West Nile virus in central Ohio, however, the specter of mosquitoes as a source of disease was resurrected. When I first heard about the disease, it sounded a little scary; it was hard to tell what was hype and what was fact. It was especially hard to figure out what the risks were so that I could put the risk of West Nile virus into perspective with, say, the proverbial risk of getting hit by lightning. Thinking about risks is something I do a lot professionally. I’m a software engineer, so I spend a lot of time thinking about cost/benefit or risk/reward trade-offs. I wanted to understand the risks of mosquito-borne disease as well as the risks from mosquito control.

On the one side, you can control mosquitoes and reduce the risks of West Nile virus. On the other side are the effects of the controls, such as risking pesticide poisoning or developing cancer. These risks need to be understood and compared when determining whether or when to apply a particular mosquito control. The risks (and costs) are what drive agencies to develop plans (often called integrated pest management plans) that determine thresholds for applying particular controls when attempting to reduce the effects of a particular pest.

In the case of mosquitoes (and West Nile virus-carrying mosquitoes in particular), a variety of controlling mechanisms is available. The mechanisms typically cited are eliminating mosquito breeding sites, education (about how to avoid mosquito bites and reduce breeding habitat), assisting groups that are at higher risk for West Nile virus (such as the elderly), controlling mosquitoes before they change into flying insects, and using pesticides.

Each of these strategies has its own costs and benefits (as well as its own risks). An integrated pest management plan would attempt to quantify the costs, benefits, and risks to minimize costs and risks while maximizing benefits. The plan would define increasing thresholds of infestation or other observations to trigger an appropriate response. Typically the plan would quantify the expected results of each particular control.

Unfortunately, Columbus doesn’t have such a plan. At last summer’s meeting, I asked the city’s mosquito control administrator about having such defined thresholds for escalating efforts (as well as well-defined goals for each effort). He dismissed the concept; his belief was that such policies were unfounded and ill-conceived. At a more recent meeting, I learned that in 2005 the Ohio Department of Health developed a mosquito management plan (replete with thresholds and goals) suitable for use by local mosquito control agencies; Columbus has yet to adopt it.

Besides having an effective integrated pest management plan, the city must act according to the agreed procedure. In the case of Columbus, the administrator said that, despite their having told folks that the city would be using the insecticide malathion for mosquito control, a permethrin-based insecticide was used. This is especially distressing since permethrins are deadly to cats. Cat caretakers should have been provided this information so that they could take precautions to minimize the risk to their companion animals. Permethrins are also extremely toxic to aquatic wildlife. Ravine dwellers and fish pond owners should have been given this information so that they could have taken precautions to opt out of spraying or to cover their ponds.

More importantly, the city must follow federal law when fogging. The U.S. EPA mandates that permethrin (and malathion) can be applied near bodies of water only when weather conditions will move the pesticide away from the water. This is to minimize the amount of poison that falls into the water.

Until a few weeks ago (when the EPA’s regional pesticide specialist intervened) the city’s mosquito control administrator maintained that Columbus was exempt from following federal law and thus did not need to take precautions around waterways. The administrator has modified the fogging policy for 2009—pesticide application will be suspended while crossing bridges that span waterways.

This is an improvement, but there is still a need to refrain from spraying around Columbus’s rivers, creeks, and lakes unless there is sufficient wind to blow the poisons away from the waterway. In the case of Columbus’s ravine-based creeks and tree-canopied rivers, it’s doubtful that enough wind would ever occur.

I’m concerned that we’re not adequately understanding the risks of West Nile virus. I’m concerned that we’re not adequately understanding the risks of the controls the city has decided to use. I’m concerned that the city is not embracing the best current practices for pest management. I’m concerned that we’re not making wise use of city funds. I’m concerned that the city isn’t doing a better job of keeping us apprised of what it is doing at our behest for the purpose of mosquito control.

As a result, I’ve created a website to document what I’ve found: “No-Spray Columbus”. Its name expresses my current thinking about mosquito control. If you are interested in working with us on this issue, please contact me through the website.

Jeff Frontz is a software engineer for a biotech startup; he spends his free time using the Internet to support environmental issues.

Editorial Note: In 1999 the Central Ohio Sierra Club brought integrated pest management expert David Frieders, Agriculture Commissioner for the City and County of San Francisco, to Columbus to meet with the Columbus Public Health Department. At that time they expressed no interest in updating their mosquito fogging policy.