Pesticide Health Effects Medical Education Database (PHEMED) 2010 Pesticide Basics Uses, Exposures, Types and Acute Effects

Pesticide Health Effects Medical Education Database (PHEMED) 2010

Pesticide BasicsUses, Exposures, Types and Acute Effects


Did you know? 5 million at risk population (U.S. EPA, 1992)

250-500 physician-diagnosed cases occur per 100,000 agricultural workers (Blondell, 1997).

Migrant and seasonal farmworkers are especially at high risk

84% of American households used pesticides, most commonly insecticides (Whitmore et al, 1992)

Homeowners use 5-10 lbs/ acre/yr on their lawns and gardens, many x greater than farmers apply to corn and soybean fields (Robinson et al, 1994).


Did you know? Non -agricultural pesticide exposure as disinfectants

widespread: (e.g., pine oil cleaners, bathroom cleaning products, and cleaning materials for swimming pools).

Non-Ag Sector a concern = pest control, nurseries, greenhouses, and landscaping.

The medical profession uses disinfectants to sanitize and sterilize surfaces and instruments.

Organophosphate and pyrethroid insecticides most implicated for poisonings.

Water chlorination is one of the largest (by tonnage) uses of pesticides.


Where Are Pesticides Used?

Forests to control insects and under-story vegetation;

Landscapes, parks, and recreational areas to control weeds, insects, and disease pests;

Rights-of-way along railroads and under electric wires to control vegetation;

Houses, schools, and commercial and office buildings to control insects, rodents, and fungi;

Boat hulls to control fouling organisms;


Where Are Pesticides Used?

Aquatic sites to control mosquitoes and weeds

Wood products to control wood-destroying organisms

Food preparation areas to control insects and rodents

Human skin to kill or repel insects

Household pets to control fleas and ticks

Livestock to control insects and other pests.


Non Occupational Pesticide Encounters

• Accidental or intentional ingestion

• Food and water residues• Contaminated clothing• Treated wood/structures• Residues on animals/carpets• Garden residues• Termite control• Hazardous waste sites/spills


Agriculture Pesticide Applications

Aerial

Air blast sprayer

Enclosed cab

Backpack wand

Boom sprayer


Agriculture Jobs

Orchard thinner Mixer loader

Flagger Picker


Professions Exposed to Pesticides

• Aerial equipment Aerial equipment maintenancemaintenance

• AgronomistsAgronomists• Building Building maintenance workmaintenance work• Emergency respondersEmergency responders• EntomologistsEntomologists• FirefightersFirefighters• ForestryForestry workers workers• Formulating end productFormulating end product• Greenhouse- nursery Greenhouse- nursery

workersworkers• Hazardous Hazardous waste waste workersworkers• LandscapersLandscapers• Livestock dippers and Livestock dippers and

veterinariansveterinarians

• Marina Marina workersworkers• Medical Medical personnelpersonnel• ParkPark workers workers• Plant pathologistsPlant pathologists• Research Research chemistrychemistry• SewerSewer work work• Storage/warehouse workStorage/warehouse work• Structural applicationStructural application• Transporting pesticidesTransporting pesticides• Treating Treating contaminated contaminated

workersworkers• Vector control workersVector control workers• Wood treatment workersWood treatment workers• Work on Work on highway highway or or

railroad rights of wayrailroad rights of way



Key Household Safety Points

1. Proximity2. Take home3. Garden4. Animals5. Recycle6. Decant7. Storage8. Disposal9. Child play/daycare

“ Partly Trained Gorillas Always Run Down Streets Doing Cartwheels”


ROUTES OF EXPOSURE

Source: EPA Protect Yourself from Pesticides-Guide of Agricultural Workers

OP’s are readily absorbed:

Across the SKIN with skin contact

In the lungs with INHALATION of pesticide contaminated air/dust

In the gut by INGESTION of pesticide residue on food/dirt/dust


Risk Factors for Occupational Pesticide

Exposures Concentration of commercial

preparations > than diluted final product = greater risk

AG workers highest exposure risk in mixing, loading, applying, and flagging.

Source: H Murphy - Cambodia


Occupational Risk Factors

• Pregnant Women: 1st trimester• Field workers entering sprayed field

before re-entry interval [REI] • Residuals on skin and clothes

– How to remove PPE– How to clean PPE– Showering after use


Evidence? Agriculture Risk Factors

• Indonesia:– Cocktail mixture of multiple products– Spray frequency– Skin contact > wet clothing– Use of toxic products (1a/Ib, II)

• Washington state: – Protective: Chemically resistant boots– Protective: Full face respirators – Risk: Mixing and loading pesticides– Risk: Cleaning equipment – Protective: Using a workplace locker for

PPE

Source: H Murphy - Indonesia


Preventing Pesticide Illness

Non-chemical Alternatives

Engineering Controls

Personal Protective Equipment

[PPE]

Primary

Secondary

Tertiary

It’s the law


Risk factors for pesticide exposures

at home

• Migrant families > risk• Children’s vulnerability • Location near fields• Take home pathway • Pesticide storage and use in homes• Multiple chemical sensitivities (MCS)


Migrant Families

• Living conditions: quality and location

• Communication: language and literacy

• Immigration status• Access to health

care• Diet


Unintentional (Accidental)

• GI absorption from accidental ingestion = acute poisonings

• Respiratory and dermal absorption from surrounding environment

• Hand to mouth activity in children


Occupational

• Dermal is most important

• Inhalation is a common pathway

• Ingestion less common but can occur if not use gloves or poor hygiene


Intentional (Suicide/Homicide/Abuse)

• Ingestion is primary pathway

• Inhalation is another pathway, although primary agents of abuse in this manner are non-pesticide chemicals (aromatic solvents).


Washington State Source of Case Reports 2002 and 2003 Combined

Source: 2004 Pesticide Incident Reporting and Tracking (PIRT) Annual Report

Poison Control

Workman’s Comp

Dept of AG



67%

Washington State Pesticide Events - 2003


Agricultural vs. Non-Agricultural Cases of

Poisonings


19992000

20012002

2003

Agricultural

Non Agricultural

72

90

62

99

111

68

113

58

75

73

0

20

40

60

80

100

120

case

s


Occupational versus Non-Occupational Cases of

Pesticide Poisoning

Occupational

52%

Non-

Occupational

48%



Proportion of PoisoningsRanked 8th Cause of Poisonings = 102,754 cases in 2005 (4.2%)

Source: Watson WA. 2004 Annual Report of the American Association of Poison Control Centers Toxic Exposure Surveillance System

Children Adults


US: Intentional vs. Accidental

6 suicide attempts used pesticides out of 196,164

8%

84%Accidental

Suicide


WHO Sentinel Surveillance

Country INDIA NEPAL INDONESIA THAILAND MYANMAR PHILIPPINESTime period 12 mo 6 mo 6 mo 6 mo 12 mo 10 moReporting sites 10 5 8 9 8 38Cases 1531 256 126 130 208 327Circumstances identified 95% 93% 96% 98% 94% 99%Intentional 89% 92% 43% 62% 86% 87%Accidental 5% 1% 16% 8% 8% 8%Occupational 6% 0% 37% 28% 0% 4%


Pesticide

Types of Pesticides

Insecticides Herbicides Fungicides Rodenticides

‘cide = to kill

DisinfectantsFumigants


Pesticide Chemical Families

-grouping based on similarities-

1. Similar chemically (similar structure)2. Attacks pests in a similar way (toxicity)3. Common treatment + antidote

OrganophosphateOP

CarbamateC

PyrethroidPY

OrganochlorineOC

Chlorophenoxy Paraquat

Diquat


Pesticide Sample Label

Type of pesticide (used for?)Company nameBrand nameCommon/generic name (active

ingredient)Chemical family (? atropine under 1st

aid)Signal word (hazard level)



Pesticide Classification Table

# Type Company

Name

BrandName

CommonName

Chemical Family

SignalClass

1.

Insecticide

Gowen Supracide

methidathion

OP(Organophospha

te)

Danger-PoisonIb


COMPANY BRAND COMMON TYPE FAMILY SIGNAL Who

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

Pesticide Labels

Bayer Temik Aldicarb Insecticide Carbamate Danger-poison la

Verdicon Sevin Carbaryl Insecticide Carbamate Caution ll

UCP Alliance Thiodan Endosulfan Insecticide Organochlorine Warning ll

Bayer Guthion Azinophos methyl Insecticide Organophospate Danger-poison lb

Dow Dursban Chlorpyrifos Insecticide Warning ll

Syngenta Gramoxone Paraquat Herbicide Paraquat Danger-poison ll

Helena Weed Rhap 2, 4-D Herbicide Chlorophenoxy Danger-poison ll

DuPont Asana Esfenverlate Insecticide Pyrethroid Warning lV

Bayer Captan Captan Fungicide Danger-poison

Max Roundup Glyphosate Herbicide Caution U-IV

II

Dow DithaneMancozeb Fungicide

Caution U-IV

Cerexagri-Nisso Ziram Ziram Fungicide Danger III

Exercise: Classifying Pesticides

Organophospate


How toxic is it?

Source: Richards, Kerry Penn State University Extension Service




LD50

Lethal dose = Amount of chemical it takes to kill 50% of an experimental population




Adapted from Richards, Kerry Penn State University Extension Service

DANGER/POISON = extremely toxic by ingestion DANGER = extremely toxic high potential for skin and eye irritation

*

*




Insecticides• ChE Inhibitors:

– Organophosphates – n-methyl carbamates

• Pyrethroids– Pyrethrins (ocloresin extract of chrysanthemum) – Pyrethroids (the synthetic derivative)

• Organochlorines (e.g. DDT)• DEET• Boric Acid• Fluorides• Nicotine • Arsenicals


Herbicides

• Chlorophenoxy herbicides (e.g. 2-4D)

• Paraquat and diquat• Pentachlorophenol and

dinitrocresol (wood preservatives)• Copper chromium arsenate

( decks, fences, and children’s wood playground sets – d/c 2003)


Fungicides

• Hexachlorobenzene• Thiram • Maneb• Methylmercury compounds


Fumigants

• Cyanide, • 1, 3-dichloropropane• Metam sodium• Methyl bromide• Naphthalene• Phosphine gas (from

aluminum phosphide)


Rodenticides

• Warfarin-related compounds: – Warfarin – Coumarins – Brodifacoum – Difenacoum (so-called

“super warfarins”)

• Others: – Thallium– Zinc phosphide– Sodium fluoroacetate


Disinfectants• Agents used for sanitization and

sterilization in the home and hospital• Registered as pesticides by the U.S. EPA• Examples include

– Alcohols – Chlorhexidine – Hypochlorites – Iodines – Phenols – Pine oil



General central nervous system • Fatigue• Dizziness• Headache• Tremors• Ataxia • Convulsions (uncommon w/carbamate)• LOC (uncommon w/carbamate)• Coma (uncommon w/carbamate)

From muscle over stimulation: • Muscle weakness• Muscle cramps• Muscle fasciculations

From gland over stimulation: • Salivary gland- excessive salivation• Sweat gland- excessive sweating• Lachrymal gland-excessive eye tearing

From organ over-stimulation: • Eyes • Gastrointestinal

• Pulmonary

•Blurred vision (constricted pupils)• Stomach cramps• Nausea• Vomiting• Diarrhea• Chest tightness• Wheezing• Cough• Runny nose

Organophosphates: 30”-240 & Carbamates: 15”-30


PyrethroidsPyrethroids: are irritants to the eyes, skin and respiratory tract. The symptoms last from 1-2 hours. Systemic toxicity from inhalation or dermal absorption is low.

Normal use: * Paresthesias (cyno pyrethroids) * Shortness of breath (wheezing)* Mucous membrane irritation (throat nose)* Skin itching

If ingested: • Loss of consciousness/coma • Seizures (cyno-pyrethroids)

High doses: • Vomiting • Diarrhea • Excessive saliva • Muscle fasciculation • Ataxia

• Irritability: to sound ~ touch

Cyno-pyrethroids: fenverlate, flucythrinate, fluvalinate cypermethrine, deltapermethrin,


Organochlorines: 10 - 480

lipophylic The nerves stimulating

glands are not affected so you will NOT see:

• excessive salivation• excessive sweating• excessive eye tearing (or over-stimulation of

small muscles like)• twitching eyelids

CNS Effects• Muscle Weakness• Dizziness• Headache• Numbness • Nausea/vomiting• LOC• Seizures• Tremors• Ataxia • Anxiety/restlessness• Confusion


ParaquatParaquat is very toxic to the skin and mucous membranes. Particles are too large to get deep into the lungs*, but once in the blood it collects in the lungs. If ingested high case fatality rate.

• Skin: • dryness, cracks• erythema • blistering• ulcerations

• Nails: • discoloration• splitting nails• loss of nails

• Respiratory tract: • cough• nosebleeds• sore throat

• Eyes: • conjunctivitis • ulceration, scarring, blindness

• Ingestion: • lung fibrosis (stiff lungs)• multi-system organ failure,

specifically • respiratory failure• kidney failure


DEETDIETHYLTOLUAMIDE

• Few toxic cases - given the widespread use

• Toxic if ingested• Children: toxic encephalopathy w/

heavy use on large surface area on kids (+ ETOH - isopropyl or ethyl)

• Dermal problems: tingling, irritation, desquamination, contact dermatitis, exacerbate pre-existing skin dz

• Kids: use 5-6.5% formulations


Boric AcidAnts, Cockroaches in Residences

“broiled lobster appearance”


Boric Acid Respiratory tract irritant

Moderate skin irritant

Historic antibacterial: poisonings from burn compresses, diaper powder, irrigation solutions

Targets: GI tract, skin, vasculature, brain

Chronic ingestion more toxic than acute (13 ½ life)

Absorption: via gut and abraded skin


Fluorides

• Transformed in stomach to corrosive hydrofluoric acid: thirst, nausea-vomiting,

diarrhea, abdominal pain

• Fluoride ion reduces extra-cellular fluid concentrations of Ca+ and Mg hypocalcemic

tetany• Cardiac arrythmias- shock 2ndary to

fluid/electrolyte imbalances, hypokalemia and the fluoride itself

• CNS H.A. muscle weakness, stupor, seizures and coma


Focus on OP’s

Children at risk for neurodevelopmental problems

Most commonly used insecticide in agriculture

Common cause of poisoning


Normal Electrical Nerve Impulse Transmission

nerve cell

muscle cell

Once acetylcholine is broken, it can no longer transmit electrical nerve impulses.

Electrical nerve impulses stop and the muscles and glands are quiet

Electrical nerve impulse coming from nerve cell stimulates the body to produce acetylcholine.

Acetylcholine acts as a bridge transmitting the electrical charge to the muscle cell.

Muscles and glands contract.

After electrical nerve impulse transmission is completed, the body produces cholinesterase.

Cholinesterase breaks up acetylcholine into acetate and choline.

acetate

choline


Organophosphate-Carbamate Disruption of Electrical Nerve Impulse Transmission Therapeutic Effect of Atropine

nerve cell

Atropine relieves the over stimulation of the muscles and glands by reducing the amounts of acetylcholine.

The effect only lasts 15 minutes. Therefore the dose must be repeated until the organophosphate binding effect has worn off.

If an organophosphate (Op) or carbamate is present, they bind with cholinesterase. [This is an irreversible effect with an Op but not with a carbamate]

The bound cholinesterase cannot penetrate acetylcholine to break it up.

The body continues to produce acetylcholine unimpeded.

This results in a build up of acetylcholine with continuous electrical nerve impulse transmission and over stimulation of muscle and glands.

muscle cell

Electrical nerve impulse

acetate

choline

cholinesterase

organophosphate

atropine


Signs and Symptoms in Adults

• Miosis• Blurring

Eye CNS Lungs GI Glands Muscle Heart

Exercise: Body Mapping

• Fatigue• Dizziness• Headache• Tremors• Ataxia • Seizures• LOC• Coma • Insomnia• Mental Δ

TightnessWheezingCoughRhinorrhea

Abd. crampsNauseaVomitingDiarrhea

Drooling

Sweating

Tearing

Weakness CrampsFasciculations

Tachy

Brady

BP

↓ BP


Signs of Pesticide Poisoning in Children

Lethargic sleepy

Seizures

Coma

Can be confused with the flu

Documents

Pesticide Health Effects Medical Education Database (PHEMED) 2010 Pesticide Basics Uses, Exposures, Types and Acute Effects