Pesticides can prevent their own detoxification.

Paraoxonase is a critical enzyme for organophosphate (OP) detoxification.

The PON1 gene is responsible for its production.

OP exposure can cause PON1 polymorphisms (variations).

Thus, OPs can prevent their own detoxification.

Examples of harm associated with the effect of OPs on PON1 activity include

  • DNA damage
  • Birth defects
  • Reduced sperm count and poorer sperm morphology
  • Clogged arteries (atherosclerosis) and coronary heart disease
  • Oxidative stress
  • Cancers and tumors
  • Whole-body inflammation (sepsis)
  • Peripheral nerve damage (neuropathy)
  • Motor neuron failure and neuromuscular disorders (myasthenia syndromes)
  • White-matter lesions in the brain
  • Parkinson's disease
  • Gulf War Syndrome

Individuals with PON1 polymorphisms prior to OP exposure are even more vulnerable.

Polymorphisms from OP exposure can happen at any stage of life.

Pregnant mothers and children under the age of two are particularly susceptible to OP exposure.

Outcomes include

  • Allergies
  • Attention deficits
  • Hyperactivity
  • Premature birth
  • Low birth weight
  • Stunted growth
  • Obesity
  • Hypothyroidism
  • Immune dysfunction
  • Congenital defects
  • Neuron cell DNA damage
  • Brain and CNS cell death
  • Developmental delays - cognitive, motor, behavioral
  • Leukemia
  • Seizures
  • Childhood brain cancer
  • Death - miscarriage, stillbirth, SIDS

Pre-natal exposure to the OP diazinon leads to children with autistic behavior.

Endosulfan and dicofol are organochlorines.

Pre-natal exposure within 500 meters of spraying led to a 6x increase in autism.

Some babies are more susceptible to OPs than other babies.

This study found newborns who were 50x more sensitive.

Newborns like these are 130x more sensitive than adults.

Pre-natal OP exposure can generate effects continuously over long periods of development.

Some effects do not appear until adolescence or adulthood.

  • Disrupted glial cell growth
  • Altered neurotransmitter function
  • Altered cell signaling
  • Behavioral deficits
  • Schizophrenia
  • Brain defects
  • Heart and liver failure

More than 100,000 chemicals are used regularly.

More than 2,000 new ones are produced annually.

Every day we ingest some of them.

Many accumulate in our fatty tissue.

In pregnant women, these accumulated toxicants pass to the fetus as it develops.

Later the toxicants are passed through breast milk.

This study examined over 300 pregnant women.

100% had at least one pesticide in their placenta.

The average pregnant woman harbored 8 different chemicals.

Some placentas contained 15 of the 17 pesticides analyzed.

These studies produced similar results.

All women carry a pesticide burden.

OPs came from the development of nerve gases during WWII.

In 2006 the EPA approved use of 32 OPs.

The EPA's own scientists complained strongly about the added risk of developmental neurotoxicity.

Currently there are 40 OPs registered with the EPA.

Organophosphates are just one class of pesticide.

Other classes include

Most organochlorine pesticides have been banned worldwide (but not quite) because of their toxicity and persistence.

DDT is the most infamous.

Exposure contiues even decades after a ban.

Dicofol and endosulfan are the only organochlorines registered for pesticide use in the U.S.

The FDA still permits the use of lindane (banned by the EPA in 2006) for treatment of head lice.

Pesticides show toxic synergy.

Current safety thresholds do not reflect real-world combinations.

Atrazine, an organochloride, is the most commonly used herbicide in the United States and probably the world.

The European Union banned atrazine in 2003.

Atrazine is associated with a wide range of toxic conditions.

Male frogs grow ovaries when exposed to 0.1 ppb atrazine in water.

Raindrops can contain 10x that level even where atrazine is not used.

The EPA permits children to drink water containing 1000x that level.

Map of atrazine in agriculture

Paraquat is an excitotoxic organochlorine linked to Parkinson's disease (see also this and this).

Farm laborers exposed to paraquat develop the disease 2x to 3x more often.

Other organochlorines behave similarly.

The CDC's biomonitoring project shows pesticide exposure is widespread and continuous.

There are many routes of exposure.

Pesticides are sprayed on crops from the air or ground, sprinkled in granular form, watered in, trenched in, time-released,...

Livestock and pets get sprayed, dusted, dipped, fogged, rubbed, collared,...

Pests get bombed, fogged, sprayed, sprinkled, coated, baited, fed,...

Imported goods get fumigated at ports of entry,...

Industrially there are releases from manufacturers, emissions from incinerators,...

... all resulting in unintended contamination elsewhere.

Running off into water

Blowing in the wind

Settling into topsoil

Clinging to crops

Getting tracked around on tires, shoes, and anything (or anyone) else that roams

Pesticides float in house dust for decades.

Carpets collect and transfer the chemicals.

Agricultural pesticides can easily drift 50 miles.

They are found at the farthest points where samples are taken.

Go farther and the chemical can still be detected.

Victims seldom recognize this far-away source of exposure.

Establishing a "buffer zone" does not ensure safety outside the zone.

Laws concerning drift are written to protect farmers from each other’s pesticides.

They are not designed to protect individuals from unwanted exposure or to protect nearby residences.

Long-term studies are in progress here.

Farm worker prior to pesticide contaminationFarm worker after pesticide exposure
Copyright © Laurie Tümer 2003
Glowing Evidence: Farmworker
Courtesy of the artist and
photo-eye gallery, Santa Fe

This image illustrates how farm workers become contaminated by pesticides while spraying in spite of wearing protective gear.

It was the starting point for further visualizations of how invisible pesticides have become the backdrop of our lives (off the farm).

Laurie Tümer's work is inspired by the research photographs of environmental scientist Richard Fenske.

This image, the foundational work in her series, incorporates many of Dr. Fenske's photographs.

Foods are a daily source of pesticide exposure.

Hundreds of different pesticides are used in food production.

The synergistic combinations are staggering.

USDA Pesticide Data Program reports from 2005 and 2006reveal

Samples Contaminated Food
5% pork muscle
6% poultry breast
8% poultry thigh
11% pork fat
13% prunes
15% sweet peas frozen
22% soybeans (especially chlorpyrifos)
25% watermelon
26% eggplant
30% peanut butter
46% grapefruit
46% winter squash
52% cantaloupe
53% orange juice
63% raisins
69% cranberries
69% plums
69% wheat (especially malathion and chlorpyrifos)
70% grapes
70% kale greens
73% collard greens
76% bananas
80% cauliflower
84% carrots
85% pears
88% broccoli
88% potatoes frozen
90% oranges
92% green beans
93% applesauce
93% strawberries
94% lettuce (43 different pesticides detected — 9 on a single sample)
94% spinach (48 different pesticides detected)
95% summer squash
98% apples (36 different pesticides detected)
99% milk
99% peaches
99% cream

It is common to find 3 or more different pesticides on a single sample.

On average, 20 different pesticides are found in any given crop.

More than 160 different pesticides were identified among all samples.

The latest Pesticide Data Program reports can be found here.

DDT was banned in 1972.

It was found in 15% of lettuce samples shown above.

It was also found in 85% of milk and 87% of cream.

DDE is a toxic metabolite of DDT.

It was found in 4% of all fruits and vegetables — but especially in spinach and kale greens.

DDE was also found in poultry and peanut butter.

Dieldrin was banned in 1974 except for termite control and then banned completely in 1987.

It was found in various samples of fresh produce including

1% of cantaloupe

7% of winter squash

9% of summer squash

23% of milk

33% of cream

The banned pesticides heptachlor (1978) and chlordane (1986) were also detected in various samples.

The reports above also found pesticides in community drinking water.

58% contained the herbicide 2,4-D (used on lawns and farms)

74% contained atrazine

19% of bottled drinking water contained residues — mostly herbicides and a fungicide.

Lindane and other pesticide residues are present in much of the world's chocolate.

This study links pesticide exposure to pregnancy-related diabetes.

Women who worked with any of these 7 chemicals during their 1st trimester had 2x the rate of gestational diabetes mellitus:




2,4,5-TP (Silvex)




This disease can cause serious health problems during pregnancy and at birth.

After an initial case, 20% to 50% of affected women will develop type 2 diabetes within 5 to 10 years.

It's a downward spiral — this study found that later stages of diabetes may cause a loss of PON1 functionality.

This DDT study shows the impact of pesticide exposure happening years before symptoms appear.

Girls exposed to pesticides during early breast development have a 5x greater likelihood of developing breast cancer later in life.

DDT was banned in 1972, but women curently reaching age 50 can experience breast now due to their childhood exposure.

The paraoxonase enzyme expressed by PON1 acts on many different kinds of toxicants (aryl esters, glucocorticoids, lactones, lipid peroxides, statins, etc.)

Disruption of paraoxonase sets up a cascade of detoxification failure and increased toxic body burden.

On top of that, chemicals other than pesticides can inhibit paraoxonase.

This causes a synergistic amplification of harm.

Interesting examples include mercury exposure, smoking, and taking drugs such as aspirin, glucocorticoids or statins.

But paraoxonase is just one of many enzymes affected by pesticide exposure.

For example, the enzyme acetylcholinesterase (AChE) is critical for neurotransmitter function.

A reduction in AChE leads directly to excitotoxicity.

OP pesticides suppress AChE.

Flying in jet aircraft can expose you to an organophosphate.

Hot air is drawn out of the engines, cooled down, and ducted into the plane cabin and cockpit.

This provides climate control inside — it is roughly -55°C outside at 8000 m altitude.

But jet oil leaks into the bleed air system and contaminates the cabin.

Maybe you've smelled it.

That jet oil contains a number of toxicants including tricresyl phosphate (TCP).

TCP is a neurotoxic organophosphate.

Symptoms of exposure include

  • Loss of concentration
  • Headaches
  • Nausea
  • Dizziness
  • Blurred vision
  • Temporary paralysis
  • Chronic fatigue
  • Chemical sensitivity
  • Long-term neurological damage

Further information starts here, here, and here.

There is an interesting correlation between pesticide use and polio.

The fate of amphibians (such as frogs) is an indicator of toxicity in humans.

Three commonly used OP pesticides — chlorpyrifos, malathion and diazinon — are highly toxic to amphibians.

Their breakdown products — chloroxon, malaoxon, and diazoxon — are 10x to 100x more toxic.

More than 6.5 million pounds of OP pesticides were used in California alone during 2004.

These pesticides are widespread, even in remote mountains areas.

General information about pesticides can be found at the Pesticide Action Network North America (PANNA).

This chart profiles many common pesticides in terms of human health and environmental effects.