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Pesticides database
Banned pesticides

Pesticides-health surveys by farmers

Chemical families of pesticides

Each pesticide generally belongs to a chemical family on which general health effects are known.

	Organophosphates: disturbs the peripheral nervous system (long acting)
	Carbamates: disturbs the peripheral nervous system (short acting)
	Organochlorines: disturbs the central nervous system (long acting)
	Pyrethroids: irritant to eyes, skin, and respiratory tract
	Thiocarbamates: irritant to eyes, skin, and respiratory tract
	Paraquat: irritant to skin and upper respiratory tract, if enters blood stream (through skin or ingestion) causes lung and kidney failure

Organophosphates

Organophosphates affect the central nervous system (brain) and peripheral nervous system (nerves found outside of the brain or spinal cord). Organophosphates attach themselves to the enzyme (acetylcholinesterase- AChE) that stops nerve transmission. Therefore, there is suppression of AChE and continuous electrical nerve transmission. This particularly affects the muscles, glands and smooth muscles that make the body organs function. 

Farmers may have the following symptoms that can appear 30 minutes after exposure and may last up to 24 hours:

	General central nervous system: Fatigue Dizziness Headache Hand tremors Staggering gait Convulsions Loss of consciousness Coma
	From muscle over stimulation: Muscle weakness Muscle cramps Twitching eyelids
	From gland over stimulation: Salivary gland- excessive salivation Sweat gland- excessive sweating Lacrimal gland-excessive eye tearing
	From organ over-stimulation:  Eyes Blurred vision (constricted pupils) Gastrointestinal Stomach cramps Nausea Vomiting Diarrhea Pulmonary (Lungs) Chest tightness Wheezing Cough Runny nose

Carbamates

Carbamates behave the same way as the organophosphates in that they suppress AChE, and cause over-stimulation of the nerves. The effect comes on sooner after exposure (as fast as 15 minutes) and does not last as long (3 hours).

Symptoms are the same with the exception of these symptoms below which are rare:

	Convulsions
	Loss of consciousness
	Coma

Organochlorines

Organochlorines affect the central nervous system. They are absorbed by fat so they can stay in the body a long time. As the fats cells in breast tissue can store organochlorines, it can measured in breast milk. The effects can occur within one hour after absorption and acute effects can last up to 48 hours. Some organochlorines (endosulfan) are rapidly and easily absorbed through the skin.

The nerves stimulating glands are not affected so you will not see:

	excessive salivation
	excessive sweating
	excessive eye tearing
	over-stimulation of small muscles like twitching eyelids

But you will see symptoms that are from disruption of central nervous:

	Muscle Weakness
	Dizziness
	Headache
	Numbness
	Nausea
	Loss of consciousness
	Convulsions
	Vomiting
	Hand tremors
	Staggering gait
	Anxiety/restlessness
	Confusion

Pyrethroids

Pyrethroids are irritants to the eyes, skin and respiratory tract. The symptoms last from 1-2 hours. The symptoms from spraying can be:

	Normal use: Numbness (hypersensitivity of skin) Shortness of breath (wheezing) Dry throat Sore Throat Burning nose Skin itching
	If ingested: Loss of consciousness/coma Convulsions
	High doses: Vomiting Diarrhea Excessive saliva Twitching eyelids Staggering gait Irritability

Thiocarbamates

Thiocarbamates are similar to the pyrethroids in that they also are irritants to the eyes, skin and respiratory tract. The symptoms can appear immediately when spraying and can be:

	Respiratory tract: Dry throat Sore Throat Burning nose Cough
	Eyes: Eye irritation (burning, itching) Red eyes
	Skin: Skin itching White spots on skin Scaling skin rash Red rash

Paraquat

Paraquat is very toxic to the skin and mucous membranes (inside of mouth, nose, eyes). Particles are too large to get deep into the lungs (manufacturer claims), but once paraquat is in the blood it collects in the lungs. If ingested (drink) it is very lethal. Symptoms can be:

	Skin: dryness, cracks erythema (redness) blistering ulcerations
	Nails: discoloration splitting nails loss of nails
	Respiratory tract: cough nosebleeds sore throat
	Eyes: conjunctivitis (irritation) ulceration, scarring, blindness
	Ingestion: lung fibrosis (stiff lungs) multi-system organ failure, specifically: respiratory failure kidney failure

Training manuals

	Farmer and school children's cross sectional survey on the health effects of pesticides
	A farmer self-surveillance system of pesticide poisoning

Download the manuals here:

Farmer-kid manual English.zip (0.74 Mb) 

Surveillance manual English.zip (0.46 Mb) 

Farmer-kid manual Thai.zip (1.49 Mb)

Surveillance manual Thai.zip (1.32 Mb)

In October-November 2002, Helen Murphy conducted training for two groups of farmers in Thailand to conduct cross-sectional surveys. More information on this training and the results of the surveys are on this website:

	Introduction
	Survey by vegetable growers Kanchanaburi
	Survey by mango growers Phitsanulok
	Conclusion

Links

	A good source of information on pesticides and symptoms of poisoning is the handbook "Recognition and Management of Pesticide Poisoning" by the U.S. Environmental Protection Agency. It can be downloaded from the EPA at http://www.epa.gov/oppfead1/safety/healthcare/handbook/handbook.htm
	More links with information on pesticides.