Brian Moench and Courtney Henley: A second opinion on the use of anti-mosquito pesticides

Chemicals used to fight mosquitoes are toxic to humans and may actually boost pest population.

(Rick Bowmer | AP file photo) In this Aug. 26, 2019, photo, Salt Lake City Mosquito Abatement District biologist Nadja Reissen examines a mosquito in Salt Lake City.

Thanks to an anachronistic 1924 law, Salt Lake City Mosquito Abatement District operates almost autonomously, with little oversight, virtually no voter accountability and little public health or environmental expertise.

Most Salt Lake City residents probably had no idea that every year SLCMAD revives a ritualistic relic of the 1970s, aerial mosquito insecticide spraying. These toxic chemicals are derivatives of WWII nerve agents and act on human nerve cells much like sarin gas does, but SLCMAD insists they are “safe” because the doses are very low and the EPA has approved these chemicals.

In a 63 page report, drawing on hundreds of studies, Utah Physicians for a Healthy Environment offers a contrasting “second opinion.” The report was reviewed by 13 physicians with substantial expertise on the human health toll of environmental toxins, many with past or present academic appointments.

Based on that report, UPHE is calling for a two-year moratorium on SLCMAD’s use of insecticides, followed by an independent analysis of the end result on human health and the Great Salt Lake ecosystem.

Because of the inherent potential conflict of interest, we also call on SLCMAD to withdraw from the American Mosquito Control Association because it accepts financial support from pesticide manufacturers and other businesses that profit from pesticide spraying.

Below is summary of our report.

1. Pesticides in general, including those used by SLCMAD, represent a widespread risk to human health, especially for the developing brain of fetuses and infants, even at the low doses common in our environment. SLCMAD’s primary insecticide, the neurotoxic organophosphate, naled, was banned by the European Union, stating naled represents “an unacceptable risk” to human health. EPA has banned it for use by home owners and on pet collars.

Nonetheless, SLCMAD relies almost exclusively on EPA approval to exonerate their spraying. But as we detailed in our report, most of the research used in EPA’s risk assessments is supplied by the chemical manufacturers themselves or from company hired contract labs. The potential for corruption is obvious, but starkly illustrated by Industrial Bio-Test Labs (IBT), the largest contract lab in the country for three decades. Several IBT executives were convicted in 1983 of extensive scientific misconduct for fraudulent research favoring industry. Thousands of IBT’s tests led to the “approval” of 212 pesticides. EPA later concluded only 16% of IBT results were valid, yet only a tiny number have been replaced and most of those pesticides are still EPA approved.

2. Volatile organic compounds (VOCs), like those from hair spray that Utah DAQ has been asking Utahns to stop using, are also released from pesticide spraying. California research found pesticide spraying contributes significantly to local air pollution.

3. A recent headline in National Geographic reads, “How pesticides can actually increase mosquito numbers.” Mosquitoes are developing resistance to common pesticides, but their predators, like damselfly larvae, are not. The end result is that pesticide spraying can actually be counterproductive, doubling the number of mosquitoes in sprayed areas compared to unsprayed areas. Another study found mosquitoes from sprayed areas tolerated 10 times the amount of chemical as did mosquitoes from non-sprayed areas. This sets up a never-ending chemical arms race.

4. We must not allow a cure worse than the disease. Nationwide the incidence of severe outcomes from West Nile Virus is very low and decreasing, despite increasing mosquito populations. Only two cases were reported in the entire state last year. All-out attempts to prevent WNV should not eclipse the long list of health and environmental concerns from pesticide use. Cities that don’t spray actually have a lower incidence of WNV than those that do. Spraying does not reduce the incidence of WNV.

5. There is no doubt pesticide spraying has adverse impacts on beneficial insects, bird populations, wildlife, and the health of the Great Salt Lake ecosystem and beyond.

6. Better, safer methods of mosquito control exist today, used by cities like Boulder, Colorado, and Madison, Wisconsin, that have abandoned the pesticide treadmill. SLCMAD can do the same and we should demand it.

Across the country mosquito districts have operated with tunnel vision of killing mosquitoes and little expertise or even appreciation of the public health and ecological consequences of their insecticides. UPHE joins many other groups in calling for a pause in this dead-end chemical arms race.

Dr. Brian Moench | president, Utah Physicians for a Healthy Environment

Brian Moench, M.D., is president and co-founder of Utah Physicians for a Healthy Environment and the author of the non-fiction books “Death by Corporation,” and “The Great Brain Robbery.”

Courtney Henley, M.D. | Utah Physicians for a Healthy Environment

Courtney Henley, M.D., is a board member of Utah Physicians for a Health Environment.