Pyrethroid Pesticides:Hidden Hazard

Rupali Das, MD, MPH, FACOEMChief, Exposure Assessment Section

California Department of Public Health Environmental Health Investigations Branch

andAssociate Clinical Professor

UCSF Division of Occupational and Environmental Medicine

Faculty Disclosure: Rupali Das, MD, MPH, has no conflict of interest to disclose.

Western Occupational and Environmental Medical Association Webinar

December 10, 2009

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Learning Objectives• Understand why illness due to pyrethroids is a concern

• Recognize settings where pyrethroid pesticides are used

• Identify potential health effects of pyrethroid pesticides

• Manage illnesses due to pyrethroid pesticides

• Learn how to report pesticide illness

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Pesticides: Defined by Law

Substances that prevent or destroy pests

• US Environmental Protection Agency▪ Federal Insecticide, Fungicide, and Rodenticide

Act (FIFRA) 1947

http://www.epa.gov/pesticides/regulating/laws.htm

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Pesticide Classes: Examples

Functional Class Chemical Class Target Organisms

Insecticide Organophosphates, Pyrethroids

Aphids, fleas, beetles

Herbicide Glyphosate Invasive grasses

Rodenticide Coumarins Mice, rats

Disinfectant Hypochlorite, Glutaraldehyde Microbes

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Many Pesticides Associated with Worker Illnesses

www.cdph.ca.gov/programs/ohsep/Documents/pestillness.pdf

Occupational Pesticide Illness in California 1998 – 2007

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Pyrethroids: Use Widespread

• Agriculture

• Structures

• Pet flea control, pediculocide

• Vector control

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Vector Control: Aircraft “Disinsection”

Source: CDC

From DDT to Pyrethroids

Sutton P. Pesticide Illness Among Flight Attendants Due to Aircraft Disinsection. Am J Indust Med. 2007; 50:345–356. http://www.cdph.ca.gov/programs/ohsep/Documents/aircraftdisinsection.pdf

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Pyrethroid ProductsALLETHRIN (Bansect Flea Shampoo)BIFENTHRIN (Speckoz Termiticide)CYFLUTHRIN (Intruder)CYPERMETHRIN (Raid, Sweep)DELTAMETHRIN (Deltox)ESFENVALERATE (CB Total Release Fogger)FENVALERATE (Tricomin)PERMETHRIN (Elimite, Nix, Off!, Raid)PHENOTHRIN (Seargant’s Flea Soap)RESMETHRIN (Scourge Inecticide)S-BIOALLETHRIN (Off! Mosquito Coil)TETRAMETHRIN (Petscription Aerosol Flying

Insect Spray) TRALOMETHRIN (Chemisco Flea Killer)

Some products listed here may no longer be registered for use

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Increasing Use

0

200,000

400,000

600,000

800,000

Pyrethroid Use in CA

Organophosphate Use in CA

Pesticide use data: www.cdpr.ca.gov/docs/pur/pur06rep/tables/table5a.htm and CDPR, personal communication 11/10/09.

Pou

nds

of R

epor

ted

Use

0

4,000,000

8,000,000

12,000,000

16,000,000

20,000,000

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

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Increasing Exposure

% of all US Insecticide Exposures Due to Pyrethroids/Pyrethrins and Organophosphates

From Power 2007. Source of data: American Association of Poison Control Centers Toxic Exposure Surveillance System annual reports

Power L. Pyrethrin and pyrethroid exposures in the United States: a longitudinal analysis of incidents reported to poison centers. J Med Toxicol. 2007; 3:94-9.

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Body, Environmental BurdenPyrethroids most common pesticide detected in homes

▫ American Healthy Homes Survey

Pyrethroid metabolites found in the urine of at least 95% of random US population tested

▪ Levels in females slightly higher than males▪ Levels in Non-Hispanic Whites, Non-Hispanic Blacks higher

than in Mexican Americans ▫ CDC National Health and Nutrition Examination Survey (N-HANES)

Urine metabolite levels in pest control operators increased after application of pyrethroid pesticides

CDC. Third National Report on Human Exposure to Environmental Chemicals 1999-2002. p. 414. www.cdc.gov/exposurereport/Stout M. American Healthy Homes Survey: National Study of Residential Pesticides Measured from Floor Wipes. Environ Sci Technol. 2009; 43:4294-4300.Leng G. Pyrethroids used indoors—biological monitoring. Int J Hyg Env Health. 2003; 206:85-92.

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Case: Farmworker24 year-old female farmworker complains of headache, eye

and throat irritation, tearing, cough, nausea, and numbness and tingling in her hands and feet.

Picking leaves off grape vines when a tractor drove by spraying cyfluthrin.

Physical exam significant for injected conjunctivae and erythema on face and dorsal hands.

Given acetaminophen and sent home. She is told to return to work the next day but comes to the clinic complaining of headache and cough. PE the next day is normal.

Symptoms persist for several days; she misses 2 days of work.

Worker Illness Related to Ground Application of Pesticide --- Kern County, California, 2005. MMWR 2006; 55:486-488. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5517a4.htm

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Pyrethrins and PyrethroidsPyrethrins• Natural chrysanthemum extract

▪ “photo-unstable”

• Low acute systemic toxicity

Pyrethroids ▪ Synthetic derivatives ▪ Increased stability▪ Human toxicity varies

Chrysanthemum cinerariaefolium, the pyrethrum flower, is the source of natural insecticidal pyrethrins

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Pyrethrins: Acute Health EffectsRespiratory sensitization• Asthma

▪ Fatalities have been reported*

Skin reactions• Paresthesias • Allergic dermatitis

* Wagner SL. Fatal asthma in a child after use of an animal shampoo containing pyrethrin. West J Med. 2000; 173:86-7.

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Pyrethroids: Acute Health Effects Skin• Paresthesia, erythema, dermatitisEyes• Severe irritation, tearing, conjunctival

and lid edemaRespiratory• Rhinitis • Increased airway responsiveness in

asthmaticsSystemic• Dizziness, headache• Fasciculations, seizuresHe F. Clinical manifestations and diagnosis of acute pyrethroid poisoning. Arch Toxicol. 1989; 63:54-58.Salome CM. The effect of insecticide aerosols on lung function, airway responsiveness and symptoms in asthmatic subjects. Eur Respir J. 2000; 16:38-43.

Top Health Effects Reported by Workers with Pyrethroid Illness CA, 1998—2007HeadacheNauseaEye Pain/IrritationDizzinessVomitingUpper Resp IrritationShortness of BreathSkin Tingling/Irritation

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Pyrethroids: Mechanism of ToxicitySodium channel toxin

Affinity for nerve membrane sodium channels Prolongs inactivation, or sodium “tail current” Highly toxic to bees, fish, aquatic invertebrates

Effects may be observed in various organs Central nervous system Gastrointestinal Respiratory Skin

Pyrethrins and Pyrethroids. http://oehha.ca.gov/multimedia/biomon/pdf/0709PyrethrinsPyrethroids.pdf

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Structure Determines Toxicity

Pyrethroid structure

Type I (non-cyano) · Shorter toxicity

Type II (-cyano)· Longer toxicity

R’R

Coats JR. Mechanisms of toxic action and structure-activity relationships for organochlorine and synthetic pyrethroid insecticides. Environ Health Perspect. 1990; 87:255-262.

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Pyrethroids: Chronic Health ConcernsAsthma in adults

• Tetramethrin, allethrin, chlorothalonil, fluazinam

Developmental toxicity• Resmethrin

Reproductive toxicity (decreased fertility)• Various

Carcinogenicity • Resmethrin - “known to cause cancer” (Prop 65)• Permethrin- “likely to be carcinogenic to humans” (US EPA)• Bifenthrin, cypermethrin, tetramethrin - possible human carcinogens

Endocrine disruption• Various

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Diagnosing Pyrethroid IllnessOccupational & environmental history• Occupation• Exposure

▪ Including use records, label, MSDS• Symptoms

▪ May be nonspecific

Physical exam may confirm suspicion• Erythema• Upper airway irritation

CDC. Recognition of Illness Associated With Exposure to Chemical Agents. MMWR. 2003; 52:938-940.

In most cases, diagnosis of pesticide illness relies on: • Clinical suspicion• Occupational and

environmental history

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Read the Label

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Pesticide Formulations

Technical grade chemical • Pyrethroid

Adjuvants/synergists• Piperonyl butoxide

“Inert” ingredients• Inert ≠ Benign

Toxic effects • may be due to any

ingredient in the pesticide formulation

• vary by product

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Laboratory ConfirmationLab tests are not needed to diagnose

pyrethroid illness

Cholinesterase tests are NOT indicated

Urine metabolites• Research method, not widely available• Indicate exposure, not physiologic effect

Future biomonitoring potential?

Leng G. Pyrethroids used indoors—biological monitoring. Int J. Hyg Env Health. 2003; 206:85-92.

Laboratory tests are not needed to diagnose most pesticide illness

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Pyrethroid Poisoning: TreatmentDecontaminate

▪ Protect treating staff

Symptomatic treatment▪ Maintain airway-breathing-circulation

Topical Vitamin E cream for paresthesias

Provide counseling on prevention

Treatment for most pesticide illnesses is based on symptoms and signs and is not specific to the pesticide

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Preventive Guidance for Workers Prevent Exposure At Work•Do not enter treated areas until it is safe•Do not bring food into a treated areas•Keep pesticides off your skin•Use respiratory protection when required•Wash hands before eating•If you become ill, tell your supervisor and seek treatment immediately

Don’t Take The Workplace Home•Do not use water in drainage ditches •Change clothes and shower if possible before entering house and or/playing with your children •Never take pesticide containers home•Store and wash clothes separately

www.cdph.ca.gov/programs/ohsep/Documents/pestillness.pdf

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Preventive Guidance for All Prevent pests• Fix leaks• Put food in tightly sealed containers• Seal cracks and holes in walls, floors,

baseboards• Keep floors and surfaces clean at all times

Use alternatives at home▪ http://www.pesticide.org/factsheets.html#alternatives

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Pesticide Reporting Regulations:Vary by State

Pesticide-related illness (WOEMA states*)▫ Reportable condition in AZ, CA, HI▫ No reporting requirement: NV, UT

*WOEMA states: AZ, CA, HI, NV, UT

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Pesticide Reporting Requirements for California PhysiciansPhysicians must report suspected

• Occupational injury or illness ▪ Within 5 days▪ To Workers’ Compensation carrier

• Pesticide Illnesses ▪ Within 24 hours▪ To Local Health Officer

▫ Who notifies other parties

Failure to comply may result in a civil penalty of $250

Treatment for pesticide illness is not first aid

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Pesticide Illness Reporting: Hawaii

Health care providers are required to report to the Department of Health within 1 day in any case of pesticide poisoning involving organophosphates or carbamates

• Oahu 808-586-4249▪ 24 hour hotline 808-247-2191

• Toll-free numbers exist for each island

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Reporting Pesticide Illnesses*Arizona

▪ www.azdhs.gov/phs/oeh/invsurv/pesticide/pestprovreport.htmCalifornia• Doctor’s First Report

▪ www.dir.ca.gov/dlsr/dlsrform5021.pdf

• Pesticide Illness Report▪ www.oehha.ca.gov/pesticides/pdf/PIR_99.pdf

• California Poison Control System▪ 1-800-411-8080 (national health care provider line)

• Confidential Morbidity Report▪ www.cdph.ca.gov/pubsforms/forms/CtrldForms/pm110.pdf

Hawaii▪ hawaii.gov/health/environmental/hazard/poison.html

*In WOEMA States

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Pyrethroids: Summary• Use is rising, exposure ubiquitous• Acute and chronic health effects• Diagnosis primarily by history• Laboratory test not clinically available• Treatment is symptomatic• Provide preventive guidance• Report pesticide illness

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Poison Control Center: 1-800-411-8080National Pesticide Information Center (NPIC)

• 1-800-858-7378 or npic.orst.eduExtoxnet: extoxnet.orst.eduHousehold Products Database: http://householdproducts.nlm.nih.gov/NIOSH: www.cdc.gov/niosh/topics/pesticides/US EPA: www.epa.gov/pesticides/index.htm

• Recognition and Management of Pesticide Poisonings. 1999; 5th ed.▫ www.epa.gov/pesticides/safety/healthcare

California Department of Public Health• www.cdph.ca.gov/programs/ohsep/Pages/Pesticide.aspx

California Department of Pesticide Regulation: www.cdpr.ca.govCA Office of Environmental Health Hazard Assessment

• oehha.ca.gov/pesticides/prgram/helpdocs1.html

Pesticide Resources

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Chronic Health Concerns: ReferencesGarey J. Estrogenic and antiprogestagenic activities of pyrethroid

insecticides. Biochem Biophys Res Comm. 1998; 251:855-859.

Hoppin J. Pesticide exposure and asthma. Am J Respir Crit Care Med. 2002;165:683-9.

Meeker J. Pyrethroid insecticide metabolites are associated with serum

hormone levels in adult men. Reprod Toxicol. 2009; 27:155-60.

Welshons W. Large effects from small exposures. I. Mechanisms for endocrine-disrupting chemicals with estrogenic activity. Environ Health Perspect. 2003; 111:994–1006.

Wigle D. Epidemiologic evidence of relationships between reproductive and child health outcomes and environmental chemical contaminants. J Toxicol Environ Health B Crit Rev. 2008; 11:373–517.

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AcknowledgmentsCalifornia Dept of Public Health•Robert Harrison•Barbara Materna

California Dept of Pesticide Regulation•Louise Mehler

Public Health Institute•John Beckman•Christine Hannigan•Patrice Sutton•Justine Weinberg

WOEMA•Shannon Jamieson•Kerry Parker•Educational Committee

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