Beyond Pesticides Urges NYC Department of Health to “Avoid Adulticiding”

“It should be noted that adulticiding for mosquito management is the least-effective method for managing mosquitoes”

Beyond Pesticides was a plaintiff, along with the No Spray Coalition, Disabled in Action, and Save Organic Standards, in a lawsuit against the City of New York around its pesticide spray program. We won that lawsuit against the City in 2006 when a federal judge ruled that the City’s spraying was a violation of the Clean Water Act. As part of the final settlement in 2007, the City admitted, signed and in writing, that the pesticides:

  • may remain in the environment beyond their intended purpose
  • cause adverse health effects
  • kill mosquitoes’ natural predators (such as dragonflies, bats, frogs and birds)
  • increase mosquitoes’ resistance to the sprays, and
  • are not approved for direct application to waterways.

Beyond Pesticides has written this important, detailed letter to New York City Department of Health Commissioner Ashwin Vasan on critical issues with the way the pesticide spraying is being conducted and a path forward to improvement.

LETTER from Beyond Pesticides:

September 23, 2022

Commissioner Ashwin Vasan, MD, PhD

New York City Department of Health and Mental Hygiene

125 Worth Street

New York, New York 10013

Dear Commissioner Vasan,

Beyond Pesticides, on behalf of our members and supporters in New York City, is writing to express concern with the mosquito adulticiding schedule approved by the New York Department of Health and Mental Hygiene (NYCDOH). Over the course of this year, the city has conducted over 15 spray events in various locations throughout the city. Beyond Pesticides has concerns about the chemicals selected by NYCDOH (in particular, the product Anvil 10+10), lack of public education on pesticide risks, and the chemical-intensive treatment approach employed.

The public health threat of mosquito-borne diseases, such as Eastern Equine Encephalitis and West Nile Virus, requires effective mosquito management. A science-based, integrated, ecological strategy for managing mosquito-borne disease emphasizes increased monitoring and surveillance, elimination of breeding sites, enhancing habitat for mosquito predators, biological controls of mosquito larvae, and public education on source reduction. To ensure public safety from both mosquito-borne and pesticide-induced diseases, it is critical that the city strives to continuously improve its approach to insect-borne disease management and limit public exposure to nervous system toxicants, such as those being used. This is generally important and of particular concern during the current threat posed by Covid, when people are more vulnerable to exposures that harm the nervous, immunological, and respiratory systems. In other words, pesticide spray events are weakening the public’s nervous, immune, and respiratory systems and increasing their vulnerability to Covid, should they contract the virus.[1]

Avoid Adulticiding

It should be noted that adulticiding for mosquito management is the least-effective method for managing mosquitoes, since most of the spray does not hit the target mosquitoes but moves through the environment and air to exposure people, wildlife, and waterways.[2] It should also be noted that regular spraying leads to resistance in mosquito populations that are hit by the spray and result in adverse impacts to predator populations that help in management.[3] 

Treatment Approach

Beyond Pesticides has serious concerns with the city’s widespread adulticiding with nervous system poisons. In the city’s Comprehensive Mosquito Control Plan for 2022, adulticiding is listed as an acceptable option (Level 3) when there is “persistent detection of mosquito-borne pathogens or detection in bridge vector mosquitoes or non-avian vertebrate populations in New York City.”[4] According to the city’s plan, this is the highest level of concern. We strongly suggest the city add additional detail to this approach that ensures that all preventive measures to manage mosquito breeding areas are aggressively undertaken. This can be accomplished by splitting Level 3 and increasing surveillance and public education when there is persistent detection of mosquito-borne disease in sentinel species or bridge vector mosquitoes, but only using adulticiding in extremely rare instances, based on the confirmed presence of a mosquito-borne disease in non-avian vertebrate populations. Then, should adulticiding be warranted in the event of such an imminent risk to public health, the city should further tier its adulticide approach with a targeted approach. Backpack applied pesticides can better target problematic areas, and the truly least-toxic products, such as organic approved or EPA 25(b) minimum risk pesticides, should be used before the application of toxic synthetic pesticides, like those being use currently.

As it currently stands, the tiered “Levels” employed by the city are not adequately protective of public health and are resulting in excessive applications of adulticides, the least-effective means of managing mosquito populations.

Public Education on Pesticide Risks

“These chemicals also harm pollinators and other nontarget wildlife.”

Synthetic pyrethroids, with the active ingredients sumithrin and prallethrin in the toxic chemical products being used—Anvil 10+10 and Duet, are associated with cancer, endocrine (hormone) disruption, reproductive effects, neurotoxicity, and damage to the kidneys and liver.5 These chemicals also harm pollinators and other nontarget wildlife. One study reports that after exposure to sublethal levels of a synthetic pyrethroid, worker bees failed to return to the hive at the end of day,  and only 43% of these bees were ultimately able to return to the hive because of disorientation due to treatment.[5] Pyrethroids have also been found to significantly reduce bee fecundity, decrease  the rate at which bees develop to adulthood, and increase their immature periods.[6] Research finds that exposure to pyrethroids reduces bee movement and social interaction.[7]

Sumithrin (d-Phenothrin) exposure can result in lung irritation and has been documented to cause asthmatic responses in those exposed.[8] The label for Anvil 10+10 provides a box with a “Note to Physician: Contains petroleum distillate – vomiting may cause aspiration pneumonia.”[9] These potential health impacts present significant concerns while Covid continues, as the virus attacks the respiratory system.

Anvil 10+10 is not a singular ingredient. It is a formulation that also contains piperonyl butoxide (PBO), a chemical listed as an active ingredient but is intended to perform the role of “synergist,” increasing the potency and toxicity of the active ingredient. The U.S. Environmental Protection Agency (EPA) considers PBO a possible human carcinogen.[10]

In addition to the respiratory irritant sumithrin and the possible carcinogen PBO, Anvil 10+10 contains “other ingredients” that are not listed, yet comprise 80% of the product formulation. We encourage NYCDOH to contact the manufacturer of this product and identify these other ingredients. If the manufacturer fails to disclose this information, citing them as trade secrets and not required to be disclosed under federal law, NYCDOH should as a public health measure not expose the public to undisclosed and potentially toxic ingredients.

Notwithstanding the secrecy of these other (or so-called “inert”) chemical ingredients, they are also not required to be tested in combination with the other active ingredients in Anvil 10+10.[11] Federal regulations under EPA only review the health and environmental effects of the active ingredients in product formulations.

None of this information is conveyed on the NYCDOH website. NYCDOH should be aware of these and other risks posed by the pesticides selected for use for the city’s mosquito management program. This is evidenced by the updated technical review conducted by the city in 2017, which outlined a range of risks and hazards posed by the chemicals employed by the city.[12] However, despite strong language around the dangers posed by mosquitoborne disease, the city downplays the risks posed by pesticide exposure.

For example, in the FAQ on the city’s comprehensive plan, it reads:

“Do the pesticides used during spraying hurt people and pets?

The City conducts spraying carefully and follows all state and federal requirements. Most people and their pets do not have health effects during and after pesticide spraying. Some people who are sensitive to spray ingredients may have short-term eye or throat irritation, or a rash. If you have stronger reactions after spraying, contact your doctor.”

NYCDOH knows, or should know, that referencing the federal requirements as an indicator of pesticide safety is misleading and not truthful. EPA’s Office of Inspector General in July 2021 stated in its report, “EPA’s Endocrine Disruptor Screening Program Has Made Limited Progress in Assessing Pesticides,”[13]:

Twenty-four years after the Food Quality Protection Act of 1996 amendments were passed, the Office of Chemical Safety and Pollution Prevention has not implemented Section 408(p)(3)(A) of the Federal Food, Drug, and Cosmetic Act to test all pesticide chemicals for endocrine-disruption activity. In addition, the OCSPP’s Office of Pesticide Programs recommended in 2015 that 17 pesticides needed additional testing for endocrine disruption in wildlife in order to provide the data needed to conduct an ecological risk assessment, but that recommendation has not been implemented. Endocrine Disruptor Screening Program testing delays are inconsistent with the Federal Food, Drug, and Cosmetic Act, which directs the EPA to take appropriate action to protect public health if a substance is found to have an effect on the human endocrine system.

There are other reports that clearly find that EPA does not disclose the unknowns and uncertainties associated with mixtures and synergistic effects and impacts to those with preexisting health conditions, and neither does NYCDOH.

The scientific literature on synthetic pyrethroids, cited in city’s technical review, notes risks related to breast cancer, endocrine disruption, developmental toxicity, liver damage, and neurotoxicity.[14] However, instead of disclosing these risks to the public, the NYCDOH website explains that “when used correctly, pesticides pose no significant health risk to people or their pets.” It is important to note that because pesticides are designed to kill, all pesticides present some level of risk to the public. EPA makes determinations on safety in the context of a statutory mandate to stop pesticides from resulting in “unreasonable risks on man or the environment.” Within this regulatory scheme, the agency permits a level of “acceptable risk” to the public. This “acceptable” risk does not constitute safety, particularly for vulnerable populations, such as young children and pregnant mothers, or those who are immunocompromised or have chemical sensitivities. Additionally, it has been found that communities of color in New York City, including landscapers, are already exposed to landscape pesticides at a disproportionate rate,[15] indicating a need to embrace strategies that reduce chemical exposure in these communities.

It is evident that NYCDOH is focused on conveying the acute risks of pesticide exposure to the public. Such an approach provides a false level of safety to vulnerable individuals who are at disproportionate risk of chronic disease from pesticide exposure. It is therefore critical that the agency convey to the public the chronic disease risks associated with the pesticide products it is employing.

Pesticide Selection

Apart from the need to further refine the decision-making process around pesticide selection and convey to the public information on the chronic risks posed by mosquito adulticides, there are emerging concerns regarding contaminants in the pesticides the city is currently using.

The product Anvil 10+10 may contain highly hazardous PFAS (per and polyfluorinated alykyl substances) “forever chemicals.” PFAS are a large family of nearly 5,000 chemicals that may never break down in the environment and have been linked to cancer, liver damage, birth and developmental problems, reduced fertility, and asthma.17 Reporting initially from the Boston Globe on preliminary testing conducted by the nonprofit organization Public Employees for Environmental Responsibility (PEER) was subsequently confirmed by EPA analysis.[16] The agency indicates that fluorinated high-density polyethylene (HDPE) used to store pesticides likely form PFAS through the container fluorination process, and have the ability to leach from their container into a pesticide product.

NYCDOH is currently using Anvil 10+10, the adulticide product that triggered this investigation, and contained levels of PFAS concerning to public health. EPA indicates that the amount of PFAS could increase over the course of storage time. As a result, Beyond Pesticides would like to know whether NYCDOH was aware of these reports. If so, what brought NYCDOH to the decision to continue using this product? Have the stocks of Anvil 10+10 that have been used this year been tested for the presence of PFAS? If not, how does the agency plan to respond?

Beyond Pesticides urges the agency to immediately stop the use of Anvil 10+10, and conduct testing on other mosquito adulticides it has used or plans to use, for the presence of PFAS.


While pesticides are often cited as a silver bullet for mosquito control, such claims are rarely if ever true. A program that focuses on killing adult mosquitoes after they are hatched, flying, and biting people and animals is the least-effective approach to mosquito management. It requires a knock-down rate of 90% of mosquitoes in a given area to achieve adequate control.[17] Research finds that aerosol plumes from truck mounted ultra-low volume spraying fail to make adequate contact with target mosquitoes at the rate necessary to achieve disease reduction.[18] And while adulticides may indiscriminately reduce some level of flying insect abundance, larval mosquitoes remain.[19] Overarching concerns regarding efficacy, repeated spraying of mosquitoes may foster pesticide resistance.[20]

We urge DOH to reform its mosquito management program: i) elevate its larviciding program, source reduction by managing breeding sites, and public education efforts to participate in removing standing water (e.g. flower pots, discarded tires, and other areas that collect water); ii) improve public education around the chronic risks posed by mosquito adulticides with new materials on their dangers; iii) tighten up on the city’s treatment approach by raising the threshold to spray adulticides, and use organic or minimum risk products by backpack in the most limited area possible first, before considering truck spraying; and iv) conduct comprehensive testing of currently-used mosquito adulticides to ensure no PFAS is present, and eliminate use of any products that do contain PFAS.

Local governments like the City of Boulder, Colorado,23 Madison, Wisconsin,[21] and Washington, DC[22]provide proof of concept that toxic adulticiding as a regular course of action throughout the mosquito season is not necessary to protect the public from mosquito borne disease and may in fact cause more harm than good.

We look forward to NYCDOH’s response and remain available to speak further about the importance of science-based, integrated, ecological strategy for managing mosquito-borne disease in New York City.


Jay Feldman                                                                Drew Toher

Executive Director                                                       Community Resource and Policy Director                                                                                                                  Beyond Pesticides



[1] Rajak, Prem. 2021. Immunotoxic role of organophosphates: An unseen risk escalating SARS-CoV-2 pathogenicity. 

[2] Pimentel, David. 1995. Amounts of pesticides reaching target pests: Environmental impacts and ethics. Journal of Agricultural and Environmental Ethics.

[3] Cox, Caroline. 2003. Insecticide Factsheet: Sumithrin. Journal of Pesticide Reform. Volume 23 #2.

[4] NYCDOH. 2022. Comprehensive Mosquito Control Plan for 2022. 5 Beyond Pesticides. 2022. Pesticide Gateway: Sumithrin and Prallethrin.

[5] Mullin CA, Frazier M, Frazier JL, Ashcraft S, Simonds R, vanEngelsdorp D, et al. 2010. High Levels of Miticides and Agrochemicals in North American Apiaries: Implications for Honey Bee Health. PLoS ONE 5(3): e9754.

[6] Dai, PL, Wang, Q, Sun, JH, et al. 2010. Effects of sublethal concentrations of bifenthrin and deltamethrin on fecundity, growth, and development of the honeybee Apis mellifera ligustica. EnvironTox. 29(3): 644–649.

[7] Ingram EM, Agustin, J, Ellis, MD, Siegfried, BD. 2015. Evaluating sub-lethal effects of orchard-applied pyrethroids using videotracking software to quantify honey bee behaviors. Chemosphere, 135: 272–277.

[8] National Pesticide Information Center. 2020. Sumithrin.

[9] Clarke. 2022. Label Anvil 10+10.

[10] EPA. 2018. Chemicals Evaluated for Carcinogenic Potential.

[11] Donley, Nathan. 2016. Toxic Concoctions: How the EPA Ignores Dangers of Pesticide Cocktails. Center for Biological Diversity.

[12] NYCDOH. 2017. Technical Memorandum.

[13] U.S. Environmental Protection Agency, Office of Inspector General. 2021. Report: EPA’s Endocrine Disruptor Screening Program has Made Limited Progress in Assessing Pesticides. Report #21-E-0186

[14] Ibid.

[15] The Black Institute. 2020. Poison Parks. 17 Harvard University. 2022. Health risks of widely used chemicals may be underestimated.

[16] Abel, David. 2020. Toxic ‘forever chemcials’ found in pesticide used on millions of Mass. Acres when spraying for mosquitoes. ; EPA. 2022. EPA Releases Data on Leaching of PFAS in Fluorinated Packaging.

[17] Pimentel, David. 2004. Encyclopedia of Pest Management.

[18] Reddy et al. 2006. Efficacy  of  Resmethrin  Aerosols  Applied  from  the  Road for  Suppressing  Culex Vectors  of  West  Nile  Virus. Vector-Borne and Zoonotic Diseases. Volume 6, #2.

[19] Jensen T, Lawler SP, Dritz DA. 1999. Effects of ultra-low volume pyrethrin, malathion, and permethrin on nontarget invertebrates, sentinel mosquitoes, and mosquitofish in seasonally impounded wetlands. J Am Mosq Control Assoc. 15(3):330-8.

[20] Cox, Caroline. 2003. Insecticide Factsheet: Sumithrin. Journal of Pesticide Reform. Volume 23 #2. 23 City of Boulder. 2022. Ecological Mosquito Management.

[21] Lafferty, Jeffery. 2021. Mosquito larvae monitoring and control – Madison metro area.

[22] District Department of Health. 2016. Arbovirus Surveillance, Mitigation and Prevention Plan 2016.

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