Inefficacy and Risks of
Adulticiding for West Nile
Virus
Presented to:
Contra Costa Mosquito & Vector Control District
Board of Trustees, Staff, and Community
By: Parents for a Safer Environment and Supporters
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PfSE is a grass-roots, volunteer group
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Director: Susan JunFish, MPH, BS
Steering Committee:
 Susan JunFish, Cynthia Mantel, Roxanna Hariri, Carol Shenon, Rita
Smith, Jane Zhai
Advisory Board:
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Sophia Chernikova, PhD, Stanford Oncology (cancer) Researcher
Naresh Duggal, MS, Santa Clara County IPM Manager
Jeremy Fish, MD, Physician & U.C. Davis Professor of Medicine
Susan Kegley, PhD, Chemist & Senior Scientist, PANNA
Ken Maderra, MS, & Larry Chen, MS, Computer Analysts
Myrto Petreas, PhD, MPH, Cal/EPA Scientist & Researcher
Debbie Raphael, MS, Toxics Reduction Manager, S.F. County
Margaret Reeves, PhD, Ecologist & Senior Scientist, PANNA
Chris Geiger, PhD, Entomologist, S.F. Dept of Environment
Cynthia Russell, MD, Oncology Surgeon
Stephen Scholl-Buckwold, PhD, Director of PANNA
Joan Reiss, RN, Consultant for Breast Cancer Fund
Mission Statement
Protect the Healthy Development of the
Most Vulnerable Population,
including the Fetus and Children,
from Preventable Environmental
Hazards
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Presentation will Address :
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Inefficacy of Adulticides
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Human Health Risks from Adulticiding
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Ecosystem Risks from Adulticiding
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Harvard Study on Efficacy, 2006
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Do Mosquito #’s Decrease
after Adulticiding as Compared
to Controls?
3 Different Suburban
Neighborhoods in MA.
Truck-based Ultra Low
Volume (ULV) Spraying
Adulticiding Pesticide Used:
Resmethrin
Sprayed at peak flight time,
2 hours after sunset.
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Harvard Study on Efficacy, 2006
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Tested on Free Mosquitoes, Not
Caged
Studied Reproductive Activity
Difference instead of infection rates.
Females that had a Blood Meal, and
may Carry West Nile virus will Attach
to the “Ovitrap” to Lay Eggs.
Counted (eggs in clumps) in Ovitraps
Laid before & after Spray.
Counted at Least 2 Days Prior to and
Up to 2 Weeks After Spraying.
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Harvard Efficacy Study Conclusion
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About as many eggs were deposited by each
species of mosquito before adulticiding as
afterwards, similar to the non-treated
neighborhoods.
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“…ULV applications of resmethrin had little or
no impact on Culex vectors or WNV, even at
maximum permitted rates of application...we
conclude that insecticidal aerosoles dispersed
from the road may not effectively reduce the force
of transmission of WNV.”
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What’s In a Pesticide?
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Active Ingredients
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Kill or repel living things.
Inert Ingredients
Make up >95% of most pesticides
 US EPA: “all inert ingredients are not non-toxic”
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Contaminants & Breakdown Products
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These can be more toxic
Only Active Ingredients are required to be labeled
although the other ingredients can be more toxic.
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Health Effects of Pesticides
Acute
asthma
 nausea
 headaches
 rashes
 dizziness
 aching joints
 flu-like symptoms
 mental
disorientation/
inability to
concentrate
 respiratory problems
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Chronic
asthma
 cancer
 birth defects &
reproductive harm
 developmental
disabilities
 endocrine disruption
 neurological toxicity
 development of
chemical sensitivities
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Pesticides: A Major Environmental
Risk
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Asthma
Reproductive Outcomes
Cancer
Dermatitis
Learning Impairments
Alzheimer’s
Parkinson’s
Chronic Fatigue
Syndrome
CA State Dept of Health Services, Office of Environmental Health
Hazard Assessment, Data Tracking Program, 2005.
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Most Vulnerable Population
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Fetus
Infants & Children
Adolescents
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The Elderly & those
with compromised
immune and nervous
systems
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Those with allergies,
liver dysfunction,
sensitivity to chemicals
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Children More Vulnerable to
Toxics
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Physiological :
 Eat,
drink & breathe more than adults
relative to body weight (higher intake)
 Immature
system less able to detoxify and
excrete chemicals as adults can
 Developing organ systems more susceptible
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Behavioral :
 Play
on floors and ground where pesticides
concentrate; get into low accessible areas
 Place hands and things in their mouths
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Cumulative Effect of Pesticides
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Exposure to very low levels of combined pesticides
result in higher toxic effects vs. single exposures.
Toxicity can cumulate across time.
Lab animals are more vulnerable to pesticide
exposures later in life when exposed to hormone
disruptors during developmental period.
Developmental exposures can cumulate with other
risk factors, such as other toxicants, advancing age
and genetic background; these can also cumulate with
exposures.
~ Deborah A. Cory-Slechta, Ph.D.
Director, Environmental and Occupational Health Sciences Institute
University of Medicine, New Jersey and Rutgers University
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An Adulticide Used: Pyrethroid Family
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CCMVCD uses “Scourge”, w/ Resmethrin.
There are ~ 20 Pyrethroids and not all have been
studied for Reproductive/Developmental
Toxicity, Hormone Disruption, and Cancer.
Pyrethroids act similarly as organophosphates,
targeting the Nervous system.
Acute Exposure: Asthma and Respiratory Effects
Chronic Exposure: Reproductive &
Developmental Damage, Cancer, and Hormone
Disruption.
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Pyrethroids Toxicity
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CCMVCD applies resmethrin at 1.52 grams/acre,
an amount that appears small.
Concentration of resmethrin just prior to
spraying is in the uM concentration range.
Breast cancer study of pyrethroids impact showed
uM concentrations triggering cancer in cells.
Wind or failure of the Spraying System can result
in unpredictable deposition of adulticides in
higher concentrations than from functioning
system.
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Pesticide Residues
Found in Every Person Tested
• Average was 13 Pesticides/Person
• 50% had 18 different Pesticides
• Children had Highest Level Pesticides,
sometimes 200% Higher
~ Center for Disease Control, 2003
• 43 of 148 chemicals studied were pesticides.
• Pyrethroids were found in most people tested,
and were the most common insecticides
~ Center for Disease Control, 2005
detected.
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Pattern: Approve Now, Ban 30 yrs Later
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DDT comes on market in 1940’s
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Diazinon & Dursban replace DDT in 1970’s
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banned in 1972 after 30 yrs of contamination.
banned in 2005 for residential application.
Pyrethroid use steps up to replace Diazinon &
Dursban in 2000’s.
Most common insecticide found in spray cans, flea
control for homes and used by pest control operators.
 CA Dept Pesticide Regulation Re-evaluating due to
risks to the environment and thus to people.
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Adulticides & Aquatic Toxicity
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Pyrethroids are very toxic to water
organisms that are used as health
indicators in sediment.
Piperonyl butoxide mixed with the
wrong, existing pesticides in creeks and
increased toxicity by 200%.
“…interaction of compounds is a
whole new issue when doing pesticide
risk assessments that has been largely
ignored by regulators…” Donald
Weston, PhD U.C. Berkeley, Dept of
Integrative Biology, Env. Toxicology
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Results from U.C. Aquatic Toxicity Study
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CA Dept of Pesticide Regulation has begun reevaluating 600 pyrethroid-containing products,
including adulticides used for mosquito control.
Regulators will have to consider toxicity of a
product from interactions of chemicals already
existing in the environment.
Interactions of PBO and pesticide residues
already existing in human bodies is now being
questioned for more research.
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American Medical Association
“Particular uncertainty exists regarding
the long-term health effects of low dose
pesticide exposure… Considering [the]
data gaps, it is prudent … to limit
pesticide exposures … and to use the
least toxic chemical pesticide or non
chemical alternative.”
~ American Medical Association,
Council on Scientific Affairs, 1997
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Pesticide Safety:
U.S. General Accounting Office
"The general public receives limited
and misleading information on
pesticide hazards and is misled on
pesticide safety by statements
characterizing pesticides as safe or
harmless."
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U.S. General Accounting Office, 1997.
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Summary of Adulticide Toxicity
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Known to be of higher risk to public health
and environment as compared to larvicides.
Pesticides even at “low doses” are linked to
illnesses such as asthma, hormone disruption,
developmental/reproductive damage, & cancer.
The Fetus, Children, the Elderly, and the
immune-suppressed are the most susceptible.
Leading Researchers, Government, and
Professional groups give warnings on Current
Exposures and Discourage Adulticiding.
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Prudent Steps for CCMVCD Board
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Suspend All Adulticiding until Efficacy of Decreasing
WNV is Shown and that the Risk from Contracting WNV
is Shown to be Higher than the Risk from Exposure to the
Adulticides.
Increase Work on Larvicing and Public Outreach to
Provide Improved Controls of Breeding Sites.
Provide a Special Public Workshop that includes
Community, CCMVCD Staff and Board members to
Discuss and Address Adulticiding and Safer Alternatives.
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Pesticide Info Resources
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UCSF Pediatric Environmental Health Specialty
Unit (PEHSU): 1-866-827-3478.
www.ucsf.edu/ucpehsu. Advice to public on
pesticide toxicity.
• Comprehensive toxicity info if you have the exact name
or US EPA registration # of pesticide: www.panna.org.
Click on “PAN Pesticide Database” on left-hand column.
• US EPA funded Pesticide Hotline: 1-800-858-7378
www.npic.orst.edu/index
• Biointegral Resource Center: www.birc.org.
Dr. Bill Quarles have reviewed efficacy of adulticiding
from studies around the world, concluding it ineffective.
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