Indoor Pesticide Health Effects Research
Research compilation supporting why indoor pesticides in schools, homes & offices
should be suspended and alternatives implemented -
Compilation of the Scientific Research
- by - December 2016
Below is a compilation of the latest research showing health problems occur with greater frequency after pesticide use inside buildings. This section pertains to the health effects on children and adults from indoor pesticide use. Health problems are typically related to the nervous system and immune systems' of occupants - resulting in increased rates of cancers, autoimmune disorders (such as diabetes and arthritis), weaker protection from viruses and damage to brain function including memory, learning and behavior. Pesticides used inside buildings create a special situation because once applied, they quickly evaporate into the indoor air and become concentrated within the closed walls of the building. This exposes occupants to higher concentrations of the chemical for days and sometimes weeks after application. Pesticides used to kill insects are technically referred to as "insecticides" and are intentionally designed to damage the nervous system of insects. Unfortunately, poisons designed to kill insects also affect people in a similar manner, but at a slower rate. Research studies were acquired from searches through the bound Index Medicus at University of Florida Shands Medical Library and through online searches through PubMed and MedLine. Click any research title below to view the journal summary or scroll down to view all studies. Doctors, researchers and media wishing to confirm our summary or get more infromation, can view the original journal article by clicking the link "View Orignal Journal" directly below each Journal name.
Child Cancer Higher- Study #1   Neurological & Behavioral Abnormalities   Flea Treatments Major Concern
Child Cancer Higher - Study #2   Non-Hodgkin's Lymphoma   Hyperactivity - Single Pesticide Exposure
Child Cancer Higher - Study #3   Mosquito Repellent DEET - Brain Damage   A.D.D. (Attention Deficit Disorder)
Child Brain Damage   Fetal Death and Malformations   Male Infertility Linked & Home Pesticides
Learning & Memory Lower   Brain Damage During Pregnancy   Pet Bladder Cancer Linked to Flea Dips
Smaller Head Circumference   Home Pesticides Increase Child Cancer   Doctors Warn Increased Child Cancer
Social Deficits in Children   Neuroblastoma Link   Infertility
Cognition & Behavior Impaired   ADHD Higher in Children   Brain Defense Damaged - Mental Illness
Child Behavior Problems   Pesticide Vapors Present Weeks/Months   Epilepsy Linked to Pesticides
Diabetes & Obesity - The Pesticide Connection   Immune System Defects After Exposure   Epilepsy - Pesticides & Defective BBB
Hyperactivity Higher   Smaller Testicles - Reduced Penis Size   Autoimmune Problems
Cancer & Viral Fighting Immune Cells Damaged   Thymus Protects from Autoimmune   Obesity Higher if Exposure in Pregnancy


Indoor Pesticides Increase Child Cancer Rates - Study #1

SOURCE: CANCER: Volume 89(11):2315-21, 2000
(An International Publication of the American Cancer Society)
View Original Journal

Lymphomas are the third most common tumor of childhood. Lymphoma is a cancer in which immune system cells called lymphocytes multiply to exceptionally high numbers and is usually found in the lymph nodes (such as under the arm and other locations).

In this study, conducted by a grant from the National Cancer Institute, it was found that children exposed to household pesticides or professional extermination methods were 3 to 7 times more likely to develop the lymphoma known as non-Hodgkin's lymphoma (NHL) when compared to children not exposed to home pesticides.  Specific types of cancer were found to occur at even higher rates. For example, home insecticides increased the risk of lymphoblastic lymphoma by 12.5 times over what would normally be expected. 

Lymphoma occurred at a rate of 21.7 new cases per million children age < 15 years in the year 2000.  Approximately 60% of these cases were NHL. 

The study included children and adolescents less than 20 years of age who were diagnosed with NHL between February 1986 and June 1990.  Tumors were classified according to cell type (predominantly B-cell or T-cell).  Telephone interviews with the mothers included questions regarding occupational and home exposure to pesticides around the time of pregnancy and direct exposure of the child to pesticides.  From a total of 268 child cancer cases (NHL), 49 children had what is called lymphomatous leukemia, while the other 218 children were diagnosed with various NHL morphologies,  including lymphoblastic subtype (38%), Burkitt lymphoma (28%),  undifferentiated (non-Burkitt) lymphoma (12%), and large-cell NHL (19%).  Frequency of household pesticide use by the mothers around  the time of the pregnancy (in utero) was associated with a 2.62-fold greater risk of NHL for limited applications (1-2 days per week), compared with a 7.33-fold greater risk for regular use (on most days).   Professional home extermination was related to a 3-fold greater risk for developing NHL.  Direct exposure of the child to pesticides after birth was associated with a 2.4-fold greater risk.

The risk for developing large cell lymphoma or Burkitt lymphoma was 6.7 and 8.0 times higher, respectively, after professional insect extermination. 

The risk for developing lymphoblastic subtype lymphoma and large cell non-Hodgkin's lymphoma was 10.9 times and 6.5 times greater, respectively, for these children compared with children who have not been exposed to pesticides. The researchers also noted a 7.1 times greater risk for Burkitt lymphoma among these children. Overall elevations in the risk associated with pesticide exposure were present for both the younger (< 6 years) and older (> 6 years) study participants.

Jonathan D Buckley, M.B.B.S. Ph.D.
Anna T. Meadows, M.D.
Marshall E. Kadin, M.D.
Michelle M. Le Beau, Ph.D.
Stuart Siegel, M.D.
Leslie L. Robinson, Ph.D.

Cancer Higher in Children when Using Home Insect Pest Control - Study #2

SOURCE:  American Journal of Epidemiology, Volume 151(7):639-46, April 2000
View Original Journal

This is another study similar to the one above which also found higher cancer rates among children living in homes where pesticides are used.

In this study, over 2,000 children with cancer were studied regarding pesticide use in their homes. This included 1,184 children with leukemia, 234 with non-Hodgkin's lymphoma and 940 children with a solid tumor.

When families used pesticides in the home for insect control (either applying it themselves or hiring professional pest control) it was associated with a 2.6 greater likelihood of the child developing lymphoma Along with this, they also found that the use of pesticides on farms was linked to a 50% increased rate of child cancer.

In conclusion the researchers stated,

The major strengths of this study were the population base and the large number of cases and controls included; a drawback was assessment of exposure on the basis of parental interviews. The data provide some evidence for an increased leukemia risk for children living on farms and for an association between use of household pesticides and risk of childhood leukemia or lymphoma.

Institute of Medical Statistics and Documentation,
Johannes Gutenberg-University of Mainz, Germany

Home Pesticides Increase Risk of Child Leukemia

SOURCE: Journal of the National Cancer Institute, Volume 79(1):39-46, July 1987
View Original Journal

Children who lived in homes where indoor or outdoor pesticides are used face a far greater chance of developing leukemia (leukemia is a cancer that occurs from having too many white blood cells in the blood). The study, published in the July 1987 issue of the Journal of the National Cancer Institute, studied 123 Los Angeles children with leukemia and 123 children without the malignancy. Results showed that children living in the pesticide treated homes had nearly a 4 times greater risk of developing the disease. If the children lived in homes where pesticides were used in the garden as well, the risk of leukemia increased to 6.5 times greater. All children in the study were 10 years of age or younger. 

Dr. John Peters 
University of Southern California  

Coughing Higher in Children Exposed to Pyrethroid Pesticide Chemicals

SOURCE:  Environment International, Volume 48: 156-161, Nov 1, 2012
View Abstract - View Journal Online

Pyrethroids are the most common pesticides now used in homes, schools, restaurants and offices. Nearly all pyrethroid pesticides (including permethrin) are mixed with a compound known as piperonyl butoxide (also called PBO). PBO is called a synergist and is added to pyrethroid pesticides because it increases the chemical's toxicity.

In this study, 224 children living in Northern Manhattan and south Bronx were studied for connections between use of pesticides and non-infectious cough. Children were measured for pesticide exposure at ages 5-6 and also to mothers during pregnancy.

No increased cough was seen with exposure to pesticides in the air, however, if children were exposed to PBO in the womb during their mother's pregnancy, they had a 27% increased rate of cough compared to other children.

Division of Pulmonary, Allergy and Critical Care of Medicine,
Department of Medicine
Columbia University College of Physicians and Surgeons
New York, NY 10032, USA.

Learning & Memory Lower in African American Children After Pesticide Exposure

SOURCE:  Environmental Health Perspectives, Volume 119(8): 1196-120`, April 21, 2011
View Journal Online

265 early elementary school children were found to score lower on tests of learning and memory if their mothers had higher levels of a common pesticide. Children were selected from low-income communities in New York City. During delivery, umbilical cord blood samples were taken from the mothers and tested for a common pesticide. The pesticide is used in agriculture and hundreds of gallons per home was applied as a termite barrier in homes built before 2000. Exposure can also occur from non-organic food sources when importing food from other countries.

After 7 years, their children were tested for ability in learning and memory using a test known as the Wechsler Intelligence Scale for Children (4th Edition). Also called the WISC, this test measures four areas of mental functioning including the Verbal Comprehension Index (which predicts school readiness), the Perceptual Reasoning Index (measures nonverbal and fluid reasoning), the Working Memory Index (measures a child's short term memory and ability to memorize new information) and the Processing Speed Index (which tests the child's ability to focus attention and scan, discriminate and sequentially order visual information). The Full-Scale IQ score is formed from the results of these four tests.

Results demonstrated a dose-effect response in which scores on the Working Memory Index declined by nearly 3% for each standard deviation increase in pesticide exposure.

In conclusion, the researchers stated:

This is of great concern as problems in working memory may interfere with reading comprehension, learning, and academic achievement.

Heilbrunn Center for Population and Family Health, Mailman School of Public Health,
Department of Biostatistics, Mailman School of Public Health
Columbia Center for Children's Environmental Health, Mailman School of Public Health
Columbia University, New York, New York
Emory University, Atlanta, Georgia

Hyperactivity Higher in Children
Exposed to Common Pyrethroid Pesticides

SOURCE:  Environmental Health, Vol. 14:44, May, 2015
View Journal Online

687 children were tested for urinary levels of the pyrethroid pesticides. Pyrethroid pesticides are used in truck and airplane mosquito control applications, food, and also for home and school pest control (including Integrated Pest Management - IPM). Children with detectable urinary levels of the pyrethroid metabolite called "3-BPA" were more than twice as likely to have hyperactive-impulsive symptoms. After that, every 10-fold increase in 3-PBA resulted in an additional 50% increase in hyperactive-impulsive behavior.

This study is of concern as pyrethroid pesticides are now commonly used as a replacement for the previously banned organophosphate pesticides. They are commonly used in school pest control - home pest control and community mosquito control applications from trucks and planes. The pesticide is also found commercially grown foods but not in organically grown foods.

Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
Rutgers Robert Wood Johnson Medical School and
Environmental & Occupational Health Sciences Institute.
Brown University of Public Health, Providence, RI


Mosquito Bug-Sprays Linked to Child Brain Damage

SOURCE:  International Journal of Developmental Neuroscience
Volume 22(1):31-37, Feb; 2004
View Journal Online

Scientists in Lucknow, India have found that the blood-brain barrier is damaged by ingredients typically used in mosquito repellents. A quick science lesson - The blood brain barrier is basically a "wall" that protects the brain from damage that would otherwise occur from the many toxic compounds in our blood. Without a properly working blood brain barrier, the brain malfunctions - resulting in a variety of neurological conditions.

Scientists tested for blood brain barrier damage using a common over-the-counter mosquito repellent containing a 3.6% solution of the pyrethroid pesticide - allethrin. Their previous work had shown that bug sprays caused significant blood brain barrier damage to newborn rat pups (Link). The current study was designed to find out what types of blood brain barrier damage would occur if exposure occurred at different times during development.

Since humans could not be directly tested using this procedure - scientists exposed "rat pups" to the mosquito/bug spray early in pregnancy and also just before and after birth. They used what is called a micromolecular tracer to determine if the pesticide "leaked" into the brain after exposure. Results showed exposure during any of the three time periods resulted in a significant break-down of the animals' blood brain barrier. Also of concern, it was found that damage persisted when tested one week after exposure. The scientists concluded by stating,

The results suggest that Mosquito Repellent inhalation during early prenatal - postnatal - perinatal life may have adverse effects on infants leading to central nervous system (CNS) abnormalities, if a mechanism operates in humans similar to that in rat pups.

Chem-Tox Comment: This study is of particular concern for the following reasons:
1) Individuals with Epilepsy, Psychosis, Depression and Alzheimer's have been found to have a weakened blood brain barrier. Thereby raising the possibility that children exposed to "bug" repellent sprays could also experience increases in these neurological conditions when older.
2) Blood Brain Barrier toxicology testing is currently not required as part of EPA's neurotoxicology guidelines (but clearly should be....). Therefore, chemical companies are not required to test or report any evidence of blood brain barrier damage.
3) Of great concern, pregnant mothers are often encouraged to apply mosquito bug sprays during pregnancy, however, this research shows that by doing so, we may very well be causing significantly more harm to the unborn child.

Developmental Toxicology Division
Industrial Toxicology Research Centre
Lucknow, India


Pesticides Reduce Head Circumference in Children
Concern for Decreased Academic Ability

SOURCE:  Environmental Health Perspectives, Volume 112(3): 388-91, March, 2004
View Journal Abstract Online
or View Entire Article in PDF

Scientists at the Mount Sinai School of Medicine investigated pesticide exposure in 404 pregnant mothers and looked for evidence of effects upon their infant's birth weight, length, head circumference and gestational age. Mothers were primarily from East Harlem, but also from other parts of New York City.

Along with measuring for blood levels of a common organophosphate pesticide, scientists also measured the mothers' blood for an enzyme known as paraoxonase (also called PON1). PON1 is an important enzyme made by the liver that flows freely in the blood and works like a magnet to grab onto and "render harmless" organophosphate pesticides in the blood.

After comparing infant growth numbers - it was found that some mothers had infants with significantly smaller head size. This reduced head size in the child only occurred if the mother was exposed to the pesticide and also had lower than average levels of PON1. Therefore, mothers with lower levels of PON1 have pesticides remain in their blood for longer periods, thereby giving more time for the pesticides to damage their unborn child's nervous system.

In conclusion, the researchers stated:

Because small head size has been found to be predictive of subsequent cognitive ability, these data suggest that chlorpyrifos may have a detrimental effect on fetal neurodevelopment among mothers who exhibit low PON1 activity.

In a related article, it was found that infants and children have greatly reduced levels of PON1 than adults and do not reach normal reach adult levels until age 7. This innate biological difference would predispose children to far more harm from pesticides than adults. This can be seen HERE.

Department of Community & Preventive Medicine
Department of Microbiology, Mount Sinai School of Medicine, New York
Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
Department of Pediatrics, Mount Sinai School of Medicine, New York


Diabetes & Obesity Higher - The Pesticide Connection

SOURCE: Reproductive Toxicology, Volume 31(3):297-301, April 31, 2011
View Journal Online

Quick Background: Cells in your body and brain use glucose for fuel, without it, they simply can't function. Diabetes is an illness in which our cells are unable to use glucose properly. This occurs from the body's inability to make or use insulin. To use an analogy; insulin is like a "bus" that carries glucose into the cell. Without the Mr. Insulin bus - glucose can't hitch a ride into the cell.

Diabetes Trends: In 1960, the percentage of the U.S. population with diagnosed diabetes was less than 1%. In 2014, 7% had diagnosed diabetes (see CDC study). This 7% is actually 10% as studies show a larger percentage of the population has "undiagnosed" diabetes. The bottom line is that diabetes continues to increase at the astounding rate of 3-4% per year in the U.S. For just Type 1 diabetes (in which a malfunctioning immune system attacks the insulin making cells of the pancreas) the annual incidence rate in the U.S. was between 10 and 20 new cases per 100,000 people - for comparison, half of the European population had incidence rates of 5 to 10 per 100,000 people (see study here). Medical costs were $245 billion in 2013 in the U.S. (American Diabetes Association website).

The Pesticide Connection: Diabetes Study at Duke University
To investigate details on a pesticide/diabetes connection in a controlled setting - researchers at Duke University exposed rat-pups to extremely low levels of 3 commonly used pesticides including - diazinon - chlorpyrifos and parathion. Levels of exposure were below that showing any sign of toxicity and on the border of detecting what is called cholinesterase inhibition. Of great interest, the researchers found that when the offspring of pesticide exposed rats consumed a high fat diet in adulthood, metabolic defects related to diabetes worsened and animals gained excess weight compared to the animals not exposed to the pesticides - in other words, pesticide exposure increased obesity and metabolic problems related to diabetes.

The scientists concluded by stating,

These studies show how common insecticides may contribute
to the increased worldwide incidence of obesity and diabetes.

Background on the Pesticides
Although diazinon and chlorpyrifos were banned in the U.S. back in 2001, people can still be exposed by living in older homes (built before 2002) or homes which have been treated for termite protection (up to hundreds of gallons were typically applied under a house foundation for termite prevention).

Faster Rise of Diabetes in Children Under Age 5
The journal Lancet reported overall annual incidence rates of Type 1 diabetes in Europe were rising at about 3.4% each year. Incidence rates of childhood diabetes varied greatly from 3.2 cases per 100,000 in the former Yugoslav Republic of Macedonia to 40.2 cases per 100,000 in two regions in Finland. Of great concern, when looking deeper, researchers found diabetes rates increasing faster for the youngest children.

1. Children ages 10-14 experienced a 2.4% annual increase in incidence per 100,000.
2. Children ages 5-9 experienced a 3.1% annual increase in incidence per 100,000.
3. Children ages 0-4 showed a much higher 6.3% annual increase in incidence per 100,000.
(The above figures were reported in Lancet, Nov 11, 2000 - see study here)

STOP SPRAYING COMMENT: Type 1 diabetes is what affects younger children - therefore, we know that children with diabetes have higher numbers of autoantibodies that attack the insulin making cells of their pancreas. Since other studies have shown autoantibodies don't decrease with age - we are left with the very logical conclusion that the younger children above are showing higher rates of diabetes because their parents have been exposed to more chemicals (and pesticides) longer than children born 10 years ago - 20 years ago - 30 years ago - etc. Keep in mind that commercial pesticides didn't begin wide scale use until the 1950's. The rate of growth of diabetes is far beyond that which can be explained by genetics or diet. This has led investigators to look at environmental causes. In a 2014 study, it was shown that 96 workers applying mosquito control pesticides in South America experienced dramatically higher rates of diabetes than similar aged people not applying pesticides (see study here).

Department of Pharmacology and Cancer Biology,
Duke University Medical Center, Durham, NC 27710, USA

Strong Link between Autoimmune Diabetes Arthritis & Pyrethroid Pesticides

SOURCE: Biochemical Pharmacology, Volume 51: 447-454, 1996
Abstract - Full Text PDF

Your thymus is arguably the most important part of your body for preventing autoimmune diseases such as diabetes type 1 - arthritis and many others. While originally thought to be important only in childhood and adolescence, it has now been found to play a crucial role in adults as well. Located above and behind the heart, your thymus functions as a "maturing and growth area" for many important immune system cells that will soon be attacking viruses and cancer - but this is just the beginning... More recently, the thymus has been found to act as a "filter" for ignorant immune system cells in the body. Like a policeman giving a test to a drunk driver, your thymus is a checkpoint for testing immune system cells on their ability to identify self (good) and non-self (bad). Normally, immune system cells attack only the bad foreign substances in the body such as viruses and bacteria and leave all your other healthy "good" cells alone. Your thymus is constantly testing the immune system cells to make sure they are smart and still know the difference between good and bad substances in the body. After giving the thymus version drunk driver test, immune cells that pass and can walk the straight line are allowed back into the bloodstream highway. If they fail the test, such as identifying healthy good tissue as invaders, they are destroyed on the spot. This critical role clearly shows that any environmental circumstance that could damage or weaken the thymus police could potentially lead to a massive increase of damaging autoimmune cells entering the bloodstream - resulting in severe negative health consequences (such as type 1 diabetes).

In this study, researchers at the Dept. of Environmental Toxicology at University of California wanted to find out if the common pyrethroid pesticide deltamethrin could damage the thymus in live animals. Deltamethrin is popular among pest control operators in the U.S. and is used in home pest control, agriculture and golf-courses. Animals were given a single injection of the pesticide at doses ranging from a low of 6 mg/kg to 50 mg/kg. The thymus was then removed from the animals after 24 hours and examined. Even at the lowest dose of 6 mg/kg - the thymus showed a 22% reduction in weight after 24 hours with increased reductions in weight as dosages increased. The researchers then performed another test to see how time affected the thymus after pesticide exposure. After exposing animals to 25 mg/kg of deltamethrin, the thymus weight was reduced by about 41% after 24 hours. During the next two weeks, the thymus continued to shrink in size daily until reaching a maximum 50% reduction in weight after 2 weeks. In conclusion, the researchers said the reduction of thymus weight (called thymic involution) was due to thymus cells being destroyed by a process known as apotosis. For a bit of good news - the thymus also demonstrated the ability to regenerate after pesticide exposure as it steadily regained about 1/3 of its lost mass after 35 days at which point the study was ended - thereby suggesting the organ could still continue to regain lost tissue and function.

Dept. of Environmental Toxicology
Intitute of Toxicology and Env Health
Center for Environmental Health Sciences
University of Califiornia
Davis, CA, USA

Increased Body Fat & Lower Birth Weight in School Age Children

SOURCE:  Environmental Health, Volume 10, September 20, 2011
View Journal Online

Chemicals such as pesticides disrupt hormones in the body and are suspected of affecting body weight and other health related issues. In this study, conducted by the University Dept. of Growth & Reproduction, researchers wanted to investigate the long term effects of non-pesistent pesticides on body weight.

The study was done by looking at 247 children born to women who worked in greenhouses using pesticides during early pregnancy. After the children were born, they were studied at 3 months of age and again at ages 6 to 11. Blood measurements were taken for IGF-1 (Insulin-like Growth Factor) - IGFBP3 (a molecule which binds IGF-1) and thyroid hormones. It is important to note that IGF-1 is similar to insulin and plays a critical role in childhood growth and is also important in adults. Body fat percentage for children ages 6 to 11 was calculated from skin fold measurements. Pesticide related compounds were also tested.

RESULTS: When compared to children not exposed to pesticides, the children born to women exposed to moderate and high levels of pesticides had significantly lower birth weight. Medium and highly pesticide exposed children also had significantly higher Body Mass Index scores (BMI). Highly exposed children had about 15% larger skin folds and higher body fat percentage than children not exposed to pesticides.

This study provides strong support for the connection between pesticide exposure and obesity in children.

University Dept. of Growth and Reproduction, Copenhagen, Denmark
Institute of Public Health, Environmental Medicine, University of Southern Denmark

Smaller Testicles & Reduced Penis Size - Linked to Mother Pesticide Exposure

SOURCE:  International Journal of Andrology, Volume 35(3):1365-2605, March 6, 2012
View Journal Online

Many pesticides are known to have endocrine disrupting abilities. The endocrine system consists of critical hormone producing glands of the thyroid, pituitary (brain), pancreas, ovaries, testes, hypothalamus (brain) and adrenal gland on the kidneys. Proper levels of endocrine hormones are critical for proper child development.

In the researchers orignal study, they found that sons of women exposed to non-persistent pesticides in early pregnancy showed signs of impaired reproductive function (reduced genital size and altered serum hormone concentrations) at three months of age. In this current study, the boys were re-examined at 6-11 years of age. 94 boys underwent genital examinations including ultrasound of testicular volumes, puberty staging and blood sampling. 59 boys were exposed to pesticides during pregnancy and 35 non-exposed children used for comparison.

RESULTS: Among the pre-pubescent boys, testicle size and penis length were reduced if mothers were exposed to pesticides. The effects were matched according to mother exposure levels, so that high-exposed boys had smaller genitals than medium-exposed boys. Boys of mothers in the high exposure group had 24.7% smaller testes and about 10% shorter penile length than boys not exposed to the pesticides. Eight prenatally exposed boys had genital malformations - no malformations were found in the non-exposed children.

University Department of Growth and Reproduction
Rigshospitalet, Copenhagen, Denmark

Behavior Problems Higher in Boys and African American Children
when Exposed to Organophosphate Pesticides

SOURCE:  Environment International, 70:125-31, September, 2014
View Journal Online

While a number of studies have shown pesticide exposure can result in lower child IQ, ADHD and other developmental disorders, scientists in this study wanted to determine if a mothers' exposure to organophosphate pesticides during the third trimester of pregnancy would increase future social problems in the children.

404 pregnant mothers were examined for urinary levels of the organophosphate pesticide metabolite DAP during their third trimester. (the metabolite appears when the liver tries to detoxify the poison). When children returned to the doctors for their 7-9 year visit, they were given the Social Responsiveness Scale (SRS) to look for abnormal social behaviors. While results showed there was no overall difference in SRS scores when looking at the 136 children who took the test as a group, there was a significant reduction in performance for black children exposed to higher levels of pesticides. Among blacks, each 10-fold increase in total DEP levels was associated with poorer social responsiveness as shown by a 5.1 point reduction in test scores.

Background: Organophosphate pesticides such as dursban (chlorpyrifos) and diazinon, have been removed from home and school use in the U.S. However, chlorpyrifos can still be used in agriculture under the name Lorsban. Exposure can come not only indoor use of pesticides, but also living close to agriculture, aerial & truck mosquito spraying and also from consumption of conventional chemically grown foods (many of which are now grown in foreign countries and imported to the U.S.).

Department of Epidemiology, Gillings School of Global Public Health
University of North Carolina at Chapel Hill
Rollins School of Public Health, Emory University, Atlanta, GA
Department of Preventive Medicine, Mount Sinai School of Medicine, New York

ADHD Higher when Children Exposed to Organophosphate Pesticides

SOURCE:  Pediatrics, 125(6): e1270-e1277, June, 2010
View Journal Online

Levels of pesticides commonly found in food appear to be increasing the risk of children developing attention deficit hyperactivity disorder (ADHD). This was the conclusion of a study conducted by Dr. Maryse F. Bourchard, PhD, and others at the Harvard School of Public Health.

1,139 children were assessed from the National Health & Nutrition Examination Survey (2000-2004). Of these 119 met the criteria for ADHD. Results showed that children with higher urinary levels of the pesticide dimethyl alkylphosphate (DAP) were twice as likely to be diagnosed with ADHD. DAP is a metabolite and marker of recent exposure to 75% of commonly used organophosphate pesticides in food. While most organophosphate pesticides have been removed from home use, they are still used as a pesticide on food and in mosquito control (e.g. malathion - Lorsban). Therefore, people consuming conventional chemically grown food or living near agriculture would be expected to have higher urinary levels of DAP, and therefore (according to these results), would be expected to experience higher rates of ADHD in children.

According to Dr. Phil Landrigan, M.D., professor and chair of the Department of Community and Preventive Medicine at Mount Sinai School of Medicine in New York City - switching to organic food has been shown to reduce pesticides levels in the urine by 85-90%. Download the full journal article from the link above.

Maryse F. Bourchard, PhD, David C. Bellinger, PhD
Robert O Writght, MD, MPH, Marc G. Weisskopf, PhD
Dept. of Environmental Health and Epidemiology,
School of Public Health, Harvard University, Boston, MA

Important Brain Defense System Damaged by Common Pesticides
Links to Epilepsy, Psychosis, Alzheimer's & Parkinson's Disease

SOURCE:  Human Experimental Toxicology, Vol. 18(3):174-9, March, 1999
View original journal online at -

Like a dam holding back the flood - the human brain is protected from harm by a defense known as the blood brain barrier. The first stage of the blood brain barrier is made from exceptionally "tight-junctions" between cells that line blood vessels supplying nutrients to the brain. When working properly, these tight-junctions prevent larger toxic molecules from squeezing-through and entering the brain cell network. Unfortunately, the tight-junctions can become "loose" after exposure to some chemicals in the environment - thereby, allowing toxic chemicals into the brain cell network with potential for causing elevated damage to the brain. Chemicals now being found to damage the blood brain barrier take on new interest as research over the past decade has found defects in blood brain barrier function in people with Psychosis(1), Epilepsy(2), Alzheimer's(3) and Parkinson's Disease(4). In this current study, scientists exposed 10 day old rat pups to three separate pesticides. This included quinalphos (an organophosphate pesticide) - cypermethrin (a pyrethroid pesticide) and the chemical Lindane (an organochlorine pesticide used in for head lice). Exposure levels were very low - 1/50th the amount that would kill 50% of the animals. To determine if the pesticides were damaging the blood brain barrier, animals were injected with a radioactive tracer. Normally, the tracer would be blocked by the blood brain barrier and not enter the brain. However, 2 hours after exposure to the pesticides, the tracer had entered the brain, thereby demonstrating blood brain barrier dysfunction. The three pesticides had disrupted blood brain barrier permeability by 130, 80, and 50% respectively. Defects in blood brain barrier function was also seen at exposure levels of only 1/100th the amount needed to kill 50% of the animals. Of significant interest, 15 day old rat pups had less barrier damage than the 10 day old rat pups. Adult rats showed no evidence of blood brain barrier damage whatsoever.

STOP SPRAYING COMMENT: Extrapolating these results to humans, we would then expect younger children to receive far more harm to their critically important blood brain barrier defense than adolescents or adults exposed to the same level of pesticides. Unfortunately, the so-called "safe" levels of pesticide exposure are currently set from research done with healthy adult animals. Hello EPA - are you listening?

1. British Journal of Psychiatry Volume 141(3):273-281, September, 1982
2. Epilepsia, Volume 47(11):1761-1774, November, 2006
3. Neurobiology of Aging, Volume 28(7):977-986, July, 2007

4. Annals of Neurology, Volume 57:176–179, 2005

Predictive Toxicology Research Group
Industrial Toxicology Research Center
Lucknow, India


Cognition and Behavioral Development Impaired
by Common Pyrethroid Pesticide

SOURCE: Toxicology Letters: 2011, June 24; 23(3):245-51

Background: The home pesticide Dursban (also known as chlorpyrifos) was an organophosphate pesticide used in homes for decades until its ban by EPA in June 2000 (It was found to cause birth defects and autoimmune disorders).  This class of organophosphate pesticides have now been mostly replaced with what is known as pyrethroid pesticides for home pest control.  In a study conducted by the Anhui Medical University in China, it was found that animals exposed to the pyrethroid pesticide fenvalerate (which contains esfenvalerate), caused impairment in spatial learning and memory.  In addition, the pesticide increased anxiety activities in females.  The harmful effects of fenvalerate occurred when the pesticide was exposed to animals during their human equivalent pubertal period.  This puberty period in animals (and humans) is a time in which hormones regulate important changes in brain structure and development.  The pyrethroid pesticide fenvalerate is believed to be an endocrine disruptor compound.  Endocrine disruptor compounds are chemicals which have the ability to mimic natural hormones in the body (such as testosterone, progesterone and estradiol), thereby, fooling the body into believing there is more or less of the natural hormone present. 
Chem-Tox Comment: Since having precise levels of natural hormones is critical for proper brain development in teenage students (and reduction of aging for adults), the potential for home pesticides to alter hormone levels during the critical window of development for teenage children, and thereby cause permanent injury to the individual, is of immediate concern.

Anhui Provincial Key Laboratory of Population Heath & Aristogenics
Department of Maternal, Child & Adolescent Health
Anhui Medical University
Anhui, China


Brain Changes - Pesticides & ADHD: A Biological Explanation

SOURCE: FASEB Journal: 29(5):1960-72, May, 2015
View journal online at

Background: The previous studies have shown Attention Deficit Hyperactive Disorder occurs with greater frequency in children exposed to pesticides. Pesticide exposure is likely to occur from their use in schools, home & yard applications, living close to agriculture and non-organic foods. This study, using mice and post-mortem brain analysis, attempted to provide a biological explanation as to why ADHD would result from pesticide exposure.

Results: After exposing pregnant mice to pyrethroid pesticides, the offspring were observed and brain structures analyzed. According to the researchers, mice exposed to pyrethroid pesticides during development exhibit hyperactivity, impulsive-like behavior, deficits in working memory and deficits in attention. Brain analysis showed the exposed mice also had elevated levels of what is called dopamine transporter and dopamine receptor levels. Dopamine is a neurotransmitter used in communication between brain cells. The picture at left is not from this study but does show a normal brain of a 20 year old young man with Learning Disabilities who died in a construction accident and reported by Dr. Albert Galaburda at Harvard Medical School. More on this and abnormal brain structures in special-ed students can be see here.

Dept. of Environmental & Occupational Med. & Environ. & Occup. Health Sciences
Rutgers-Robert Wood Johnson Medical School
Center for Neurodegenerative Disease, School of Medicine, and
Department of Environmental and Occupational Health
Rollins School of Pubic Health, Emory University, Atlanta, Georgia

Cancer & Virus Fighting Immune System Cells Damaged by Pesticides

SOURCE:  Environmental Toxicology, Volume 19(6):554-63
December 2004

The backbone of your immune system is composed of cells that continuously roam your blood looking for germs, bacteria, viruses, parasites and cancer cells. If your doctor has ever drawn blood from your arm, he may have done what is called a CBC (Complete Blood Count). This will tell him the number of immune system fighting white blood cells you have. The so-called normal range is typically between 4,000 and 11,000 white blood cells per cubic millimeter of blood (a millimeter is less than 1/16th of an inch). The word "normal" is actually more of an "average" and what is applied to the middle 95% of the population. People with the lowest 2.5% and highest 2.5% are not included. As far as the numbers go, it is better to be in the upper half of this range, thereby giving you more immune cells to fight bacteria, viruses and cancer. People at the very low end of "normal" are typically predisposed to higher rates of infection. Approximately 5% of your white blood cells (cells of the immune system) are called natural killer cells. These cells perform a critical role in destroying early stages of viral infections and cancer. In a study done at the Department of Chemistry, Tennessee State University, researchers found that very low levels of carbamate pesticides used in agriculture could weaken the ability of natural killer cells to destroy viruses or cancer cells. To quote the scientists,

"A concentration of ziram (carbamate pesticide) as low as 12 nM produced significant loss of cytotoxic function in highly purified NK (natural killer) cells (65% decrease in function after 6 days). The toxicity of each of the compounds studied increased very significantly with length of exposure."

Barbara A. Cohn, Michele La Merrill, Nickilou Y. Krigbaum, Gregory Yeh, et. al.
Child Health Development Studies, Berkeley, California
Department of Environmental Toxicology, University of California, Davis


Breast Cancer Linked to Home Pesticide Chlordane

SOURCE:  Breast Cancer Research and Treatment, Volume 90:55-64, 2005

One in eight women in the United States will develop breast cancer according to the latest statistics.  Breast cancer rates in the U.S. are 3-7 times higher than those in Asia.  This 2005 study conducted at the US Army Institute of Surgical Research and Texas Tech University Health Science Center in Lubbock Texas found that cancerous human breast tissue contained the chemical heptachlor epoxide (found in the common home pesticide chlordane) at levels 4 times higher than non-cancerous breast tissue.  Chlordane was the primary termite prevention pesticide used in over 30 million U.S. homes between the mid 1950's and 1988.  An estimated 50 million U.S. residents are currently exposed to the volatization of this chemical from previously treated pre-1989 homes on a daily basis.  (For more information on chlordane go to our Chlordane Web page ).

Dr. Richard A. Cassidy, Sridhar, George M. Vaughan
Tox Free, Inc., Tell City, IN
Texas Tech University Health Science Center, Lubbock, TX
US Army Institute of Surgical Research

Non-Hodgkin's Lymphoma Linked to Pesticides & Chemicals

Why does the National Cancer Institute Leave Out these Earlier Figures?

SOURCE:  Annals of Oncology, 5(1):S19-S24, 1994

CHEM-TOX Introduction:  Non-Hodgkin's Lymphoma (NHL) is a blood cancer that continues to increase rapidly in industrialized countries.  NHL is considered similar to leukemia by many experts but is characterized by exceptionally high numbers of a type of white blood cell known as "lymphocytes." Lymphocytes primarily attack viruses and cancer. Lymphocytes are approximately 30% of all white blood cells and are manufactured in the body's lymph glands (ie. tonsils. As stated in the abstract below - rates of NHL have grown dramatically over the past 30 years. Below are reported NHL incidence rates for the U.S. population

1950: 6 per 100,000 people
1975: 9 per 100,000 people
1989: 14 per 100,000 people
2016: 22 per 100,000 people

The 2016 figure is based upon a U.S. population of 325 million and a National Cancer Institute estimate of 72,000 new cases of NHL in 2016. (Dividing 325 million by 72,500 shows 1 new case of NHL per 4,482 people. This rate = 22 new cases of NHL per 100,000 people. For comparison, in 1950, the rate of NHL was 6 per 100,000 people and has steadily increased. Of interest is that figures reported by the National Cancer Institute website show rates beginning in the 1990's and ignore the lower rates before 1990, thereby leading people to believe that these "higher rates" have been common throughout the century (which they have not).

Below is the abstract from this article:

The epidemiology of Non-Hodgkin's lymphoma (NHL) was reviewed. In the United States, the annual incidence of NHL rose from 5.9 per 100,000 people in 1950 to 9.3 per 100,000 in 1975, to 13.7 in 1989. The elderly showed the greatest increase. Most of the recent increase was not attributable to acquired immune deficiency syndrome. Mortality rates due to NHL were increasing at almost 2% per year. The largest proportional increases occurred in the brain and other areas of the nervous system. Occupational studies have indicated that persons with certain jobs have an increased risk, including farmers, applicators of pesticides, grain millers, wood and forestry workers, chemists, cosmetologists, machinists, printers, and those working in the petroleum, rubber, plastics, and synthetics industries. A three to nine fold increased risk of developing NHL was noted for patients receiving treatment with alkylating agents or radiotherapy. The most extensive data related to pesticides and the occurrence of NHL suggest that exposure to phenoxy herbicides, particularly 2,4-D (94757), is linked to NHL. Flour millers exposed to fungicides and fumigant pesticides had over a four fold increased risk of NHL; long term follow-up indicated this risk increased to nine fold. An etiologic link between exposure to various solvents and NHL has been defined by recent studies including benzene (71432), styrene (100425), 1,3-butadiene (106990), trichlorethylene (79016), perchloroethylene (127184), creosote (8021394), lead-arsenate (10102484), formaldehyde (50000), paint thinners, and oils and greases. Recent findings also indicated an increased risk of NHL in those exposed to dusts and particles, hair dyes, and cigarette smoke. An association was noted between NHL and Helicobacter-pylori infection. Nitrate contamination of groundwater also may be linked to increased incidences of NHL.


Mosquito Repellent DEET Linked to Nervous System Damage

SOURCE:  Environmental News Service, May 10, 2002

DURHAM, North Carolina, May 10, 2002 (ENS) - A common ingredient in mosquito and tick repellents may be linked to some neurological problems, a new study suggests.

A Duke University Medical Center pharmacologist is recommending caution when using the insecticide DEET, after his animal studies last year found the chemical causes diffuse brain cell death and behavioral changes in rats after frequent and prolonged use

Mohamed Abou-Donia, PhD has called for further government testing of the chemical's safety in short term and occasional use, particularly in view of Health Canada's recent decision to ban products with more than 30 percent of the chemical.

Every year, about one-third of the U.S. population uses insect repellents containing DEET, available in more than 230 products with concentrations up to 100 percent. While the chemical's risks to humans are still being intensely debated, Abou-Donia says his 30 years of research on pesticides' brain effects indicate the need for caution among the general public.

His numerous studies in rats, two of them published last year, demonstrate that frequent and prolonged applications of DEET cause neurons to die in regions of the brain that control muscle movement, learning, memory and concentration. Rats treated with an average human dose of DEET - 40 milligrams per kilogram body weight - performed far worse than control rats when challenged with physical tasks requiring muscle control, strength and coordination.

Such effects are consistent with physical symptoms in humans reported in the medical literature, such as those experienced by some Gulf War veterans, said Abou-Donia.

"If used sparingly, infrequently and by itself, DEET may not have negative effects - the literature here isn't clear," Abou-Donia said. "But frequent and heavy use of DEET, especially in combination with other chemicals or medications, could cause brain deficits in vulnerable populations."

Children are at particular risk for subtle brain changes caused by chemicals in the environment, because their skin more readily absorbs them, and chemicals may affect their developing nervous systems, said Abou-Donia.

Preparations like insecticide based lice killing shampoos and insect repellents are assumed to be safe because severe consequences are rare in the medical literature. Yet subtle symptoms, such as muscle weakness, fatigue or memory lapses, might be attributed to other causes in error, Abou-Donia said.

"The take home message is to be safe and cautious when using insecticides," said Abou-Donia. "Never use insect repellents on infants, and be wary of using them on children in general. Never combine insecticides with each other or use them with other medications. Even so simple a drug as an antihistamine could interact with DEET to cause toxic side effects. Don't spray your yard for bugs and then take medications. Until we have more data on potential interactions in humans, safe is better than sorry."


Neuroblastoma Linked to Homes Treated with Pesticides

SOURCE: Epidemiology: 12(1):20-26, January, 2001

One of the largest studies to date has found that pesticide use around the home can more than double the chance of a child developing neuroblastoma.

Neuroblastoma accounts for approximately 10% of all childhood tumors.  There are 550 new cases in the United States each year, with an annual incidence rate of 9.2 cases per million children under 15 years of age.  This works out to approximately 1 per 100,000 children under age 15 on a national level.  (These rates were reported in the book "Principles and Practice of Pediatric Oncology, Lippincott-Raven, 1997).  It is a very serious cancer as approximately 60% of children over age 1 who develop neuroblastoma do not live 3 years even when receiving treatments of radiation and chemotherapy.  Children under age 1 have a more positive prognosis.  As statistics show that neuroblastoma rates have increased over the past 50 years, it is reasonable to assume environmental factors may be involved.

One of the largest collaborative efforts among 7 Universities and medical facilities worked together to determine what extent pesticide use in the home could increase child neuroblastoma rates.  390 neuroblastoma children and 460 non-cancer controls were included in the study.  Investigators questioned both parents regarding use of pesticides in and around the home.

Results showed that using pesticides in and around the home resulted in a 60% increased likelihood of children developing the disease (Odds Ratio=1.6).   Looking at pesticide use for the lawn and garden only resulted in an increased risk of 120% (Odds Ratio=2.2) when the mother had applied pesticides in the yard and 50% higher (Odds Ratio=1.5) when the father had applied pesticides in the yard. (Chem-Tox Note: Outdoor pesticides are much different from indoor pesticides as they include fungicides and herbicides some of which have been reported to contain dioxin.

Julie L. Daniels, Andrew F. Olshan, Kay Teschke, Irva Hertz-Picciotto, Dave A. Savitz, Julie Blatt, Melissa L. Bondy, Joseph P. Neglia, Brad H. Pollock, Susan L. Cohn, A. Thomas Look, Robert C. Seeger, Robert P. Castleberry
Department of Epidemiology, School of Public Health, University of North Carolina, Chapel Hill, University of British Columbia, University of Texas, University of Minnesota, University of Florida, Northwestern University, Department of Experimental Oncology, St. Jude Children's Research Hospital and University of Alabama


Evidence Suggests Child Brain Development Harm During Pregnancy from Common Pesticide Chlorpyrifos (Dursban)

SOURCE: Toxicology and Applied Pharmacology 134, 53-62, 1995

Chem-Tox Comment: During the past 30 years there has been an alarming rise in the rates of children exhibiting various forms of subtle brain damage including - learning disabilities - autism - and attention deficit disorder.  Understanding that the human brain begins growing at over 4,000 cells per second beginning in the 4th week of pregnancy demonstrates the importance of having a non-contaminated biological environment in order to attain maximum brain growth quality.  The following research was conducted at the Department of Pharmacology, Duke University Medical Center, Durham, North Carolina.  The first paragraph below is taken from the abstract of the original research.

"Researchers administered chlorpyrifos to neonatal rats in apparently subtoxic doses that caused no mortality and little or no weight deficits and examined developing brain regions (cerebellum, forebrain, brainstem) for signs of interference with cell development.  One day old rats given 2 mg/kg of chlorpyrifos showed significant inhibition of DNA synthesis in all brain regions within 4 hours of treatment; equivalent results were obtained when a small dose (0.6 ug) was introduced directly into the brain via intracisternal injection, indicating that the actions were not secondary to systemic toxicity.  Inhibition of DNA synthesis was also seen at 8 days of age; however, at this point, there was regional selectivity, with sparing of the cerebellum...  These results indicate that low doses of chlorpyrifos target the developing brain during the critical period in which cell division is occurring, effects which may produce eventual cellular, synaptic, and behavioral aberrations after repeated or prolonged subtoxic exposures."

In summary the researchers stated,

"In extrapolating findings in the developing rat brain to man, it is important to note that the first 10 days of postnatal life in the rat represent stages of neurodevelopment corresponding to the last trimester of gestation in man; thus, our finding of a much greater sensitivity to chlorpyrifos in the neonate, in terms of both systemic toxicity and targeting of DNA and protein synthesis within the brain, emphasize the need for caution in assigning safety standards.  Further study of acute and chronic exposure to chlorpyrifos should be undertaken to evaluate the cellular, synaptic, and behavioral consequences of low-level exposures.

K. D. Whitney,  F. J. Seidler,  T.A. Slotin
Department of Pharmacology
Duke University Medical Center
Durham, North Carolina


Prostate Cancer Risk Doubles in Pesticide Applicators

SOURCE: Occupational Environmental Medicine, 56(1):14-21, 1999

OBJECTIVES: Although the primary hazard to humans associated with pesticide  exposure is acute poisoning, there has been considerable concern  surrounding the possibility of cancer and other chronic health effects in  humans. Given the huge volume of pesticides now used throughout the world,  as well as environmental and food residue contamination leading to chronic  low level exposure, the study of possible chronic human health effects is  important.
METHODS: This was a retrospective cohort study, analyzed by general standardized mortality ratio (SMR) of licensed pesticide  applicators in Florida compared with the general population of Florida. A  cohort of 33,658 (10% female) licensed pesticide applicators assembled  through extensive data linkages yielded 1874 deaths with 320,250  person-years from 1 January 1975 to 31 December 1993.
RESULTS:  Among male applicators,  prostate cancer mortality (SMR 2.38 (95% confidence interval (95% CI) 1.83  to 3.04) was significantly increased. No cases of soft tissue sarcoma were confirmed in this cohort, and non-Hodgkin's lymphoma was not increased. The  number of female applicators was small, as were the numbers of deaths.  Mortality from cervical cancer and breast cancer was not increased.  Additional subcohort and exposure analyses were performed.

Fleming LE, Bean JA, Rudolph M, Hamilton K
Mortality in a cohort of licensed pesticide applicators in Florida.  
Department of Epidemiology and Public Health
University of Miami School of  Medicine, FL 33101, USA.

Pesticide Vapors Present - Weeks - Months - Years after Application 

In research to determine the amount of indoor air contamination following routine indoor application of pesticides, it was found the levels of the pesticide Dursban drop to only one-sixth of its original 1 hour level four days after application. The research was conducted by Dow Chemical (1). The no-odor pesticide Ficam was reported to have an air half-life of approximately 10 days (2).  Of significant concern is the discovery that the pesticide soil drench procedure (a procedure in which approximately 200 gallons of pesticides are saturated into the soil just prior to the pouring of the concrete foundation in new home construction) is finding its way into the indoor air for literally years and years after application.  It was originally thought that the concrete foundation provided a solid barrier to the poison.  However, air testing technology has shown this is not the case (3). Just as radon finds its way into a home, entering from the soil, the pesticide vapors do also moving from the high pressure underneath the home and into the lower pressure inside the home.  It enters through cracks in foundation, around plumbing fixtures, etc.  This provides strong evidence that this procedure should be eliminated immediately and alternative methods be used.   Alternative methods include using only concrete and metal framing - using   non-volatile Sodium Borate treatment on the wood framing before installing drywall - using pesticide spikes embedded in the soil around the perimeter of the home (this is still a chemical pesticide and therefore is not a first option but may satisfy the Lenders).  Other research at University of Florida has shown that larger "sand" granules do not allow termites to build their nests.  Unfortunately, the pesticide industry has worked its way solidly into new home construction practices and therefore takes a little effort on the homeowner's part to stop the pesticide soil drench procedure - (It can be done however, as it is not a law, but rather a recommended procedure in the Southern Building Code and one the lenders like to see done. Go talk to your lender personally and tell them about the alternatives and threaten to take your business somewhere else.).  The bottom line is these chemicals do enter the home and they do accelerate the onset of health problems (as seen in the research on this page) including aging of the immune and nervous system and therefore should not be applied underneath the home. 
We have also made a table summary on the the Indoor Air Pesticide Contamination Research.
  1. Pest Control Technology Magazine, pg. 44, August 1987
  2. Peter Drury (M.S.) Pesticide Telecommunication Network, Dallas, Texas 1-800-858-7378 (
    This organization is partially funded by the EPA)
  3. Indoor Air Pesticide Summary - click to see summary and references

Immune System Problems Appear After Indoor Dursban Exposure

SOURCE: Archives of Environmental Health, 48(2):89-93, March/April 1993

The pesticide Dursban (also called chlorpyrifos), commonly used in indoor and lawn pest control, is now showing evidence of causing immune system disorders in people. In a study by the Department of Health Science at California State University, 12 individuals, which included a teacher, six housewives, a retail owner, a musician and an engineer, were studied for 1 to 4.5 years after they became ill when their home or place of employment was treated with the pesticide. The researchers were investigating for any abnormalities in immune system function. Immediately following each patient's exposure to the pesticide, common complaints included an initial flu-like illness followed by chronic complaints of fatigue, headaches, dizziness, loss of memory, upper and lower respiratory symptoms, joint and muscle pain and gastrointestinal disturbances. The subjects were found to have an elevated number of CD26 cells and a higher rate of autoimmune problems, compared with two other control groups. (Autoimmune disorders occur when the person's own immune system mistakenly makes antibodies which attack their own body.) Autoantibodies were found toward smooth muscle, parietal cell, brush border, thyroid gland, myelin, and ANA. 83% of the pesticide exposed people were found to have autoantibodies in their blood, in comparison to only 15% for non-exposed control group. 50% of the pesticide exposed people were also found to have two or more autoantibodies in comparison to only 4% for the non-exposed group. 

In conclusion the researchers stated, 

"the presence of several different types of autoantibodies, e.g., antimyelin, antismooth muscle, anti brush boarder, and antimicrosomal, indicates that generalized tissue injury has occurred. Moreover, these identical observations have been made in additional chlorpyrifos patients (research in progress). Thus, chlorpyrifos (Dursban), as used in pesticide spray, should be examined more closely as a probable immunotoxin."

Jack D. Thrasher Ph.D., Roberta Madison, Alan Broughton 
Department of Health Science, California State University 


Flea Home Treatments Cause High Air Pesticide Levels

SOURCE: American Journal of Public Health, 80(6):689-693, 1990 

Applying common flea pesticide treatments to carpets results in illegally high air pesticide levels in homes which lasts for over 24 hours after application. This was the conclusion of research conducted by Dr. Richard A. Fenske, Assistant Professor at Rutgers University. Tests were conducted by applying the common pesticide Chlorpyrifos (Dursban) for flea treatment by a licensed Pest Control Applicator to three rooms of an unoccupied apartment in New Jersey in June, 1987. Air sampling equipment was installed above the floor at the levels expected for an adult sitting in a chair and that of an infant. After application, samples were taken at 30 minutes, 1 hour, 1.5 hours, 3 hours, 5 hours, 7 hours and 24 hours. Results showed that at 5 hours post application, indoor air levels of the pesticide was nearly twice above the legal limit in homes with ventilation (an open window) and over 6 times above the legal limit at 7 hours where windows were closed. Levels at the infant breathing zone were nearly 10 times above the legal limit at 7 hours and over 3 times the legal limit even after 24 hours. These results show it is incorrect when Pesticide Applicators state it is safe to return home several hours after application. In fact, levels at 7 hours were 3-5 times higher than the 1.5 hour level. In conclusion the researchers stated, 

"Despite uncertainties in exposure/absorption estimates and toxicological interpretation, the dose values derived in this study raise a public health concern. Broadcast applications and possibly total release aerosol/fogging applications of acutely toxic insecticides may result in dermal and respiratory exposures sufficient to cause measurable toxicological responses in infants. 

Richard A. Fenske, Ph.D., MPH
Kathleen G. Black, MPH
Ken P. Elkner, MS 
Department of Environmental Sciences 
Graduate Program in Public Health, Rutgers University 


Pesticide Inhalation Associated with Brain and Lung Cancer

SOURCE: Journal of the National Cancer Institute, 71(1), July 1983   

A study of 3,827 Florida pesticide applicators employed for 20 or more years found they had nearly 3 times the risk for developing lung cancer. The same study also showed the pesticide applicators had twice the risk for brain cancer. There was not any increased cancer risk when applicators were studied for only 5 years implying it takes over 5 years to accumulate enough damage to the genetic structure to develop the cancers. 


The Pesticide Chlordane Contaminates Most U.S. Homes

SOURCE: Teratogenesis, Carcinogenesis, and Mutagenesis 7:527-540, 1987 

There is approximately a 75% chance you are breathing the pesticide chlordane every minute you are inside your home if your home was built before March of 1988. Other studies have shown there is a 6-7% chance you are breathing dangerously high levels of the pesticide which are above the guidelines set by the National Academy of Sciences. This problem is occurring because over 30 million homes were treated with the chemical prior to its being banned by the EPA in March of 1988. The air chlordane studies were conducted by the U.S. Air Force and the New Jersey Department of Environmental Regulation. Over 1000 homes and apartments were tested in different parts of the nation. The researchers stated they expect the figures to remain the same throughout the country because of standardized application practices by the pest control companies. If you would like more detailed information on the chlordane problem and the health effects suspected for the millions of Americans living in chlordane treated homes - visit the chlordane web site by clicking this link.  

Samuel S. Epstein and David Ozonoff 
Chief Environmental Health Section 
Boston University School of Public Health, Boston Massachusetts 


Common Pesticides Cause Hyperactivity in Test Animals  
After Single Dose

SOURCE: Neurotoxicology and Teratology, Vol. 11:45-50, 1989 

Groups of test animals exposed to different pesticides used in agriculture and lawn care showed over 50% more activity following a single exposure to the chemical. One of the main goals of this experiment, conducted by Dr. J. A. Mitchell and colleagues at the University of Michigan, was to investigate activity behavioral changes in test animals (male Swiss mice) following a single exposure to one of 4 different dosages of weed killers and fungicides. The chemicals used included Lasso (containing alachlor), Basalin (containing fluchloralin), Premiere (containing dinoseb) and the fungicide Maneb-80 (80% Maneb).. Test dosages ranged from a very low 0.4 mg/kg to 4 mg/kg to 40 mg/kg. Even the largest dose was still below the LD-50 for the animals (the amount needed to kill 50% of the test animals). According to the researchers, the herbicides and fungicides have received few reports investigating their toxicity while their yearly growth and production have grown far more than the insecticides. 

The detection of hyperactivity was measured by placing the test animals in steel cages that were equipped with electronic motion detectors which used infrared beams to count specific movements by the animals. After the single chemical exposure, activity was measured for a 4 hour period. Results showed the weed killer "Lasso" did not show any effects at the very low .4 mg/kg level but did show over a 65% increase in activity at the low 4 mg/kg and a 75% increase at the higher 40 mg/kg level. The weed killer Dinoseb also showed no activity increases at the lowest .4 mg/kg dose but did show a 15% increase at the 4 mg/kg level and a 54% increase at the larger 40 mg/kg level. Other researchers have reported that activity provides a sensitive measure for evaluating the behavioral effects of the pyrethroid pesticide, deltamethrin, at doses that did not cause the characteristic neurotoxicological syndrome (6). 

In conclusion the researchers stated, 

"The results of this study suggest that at least some herbicides, in addition to pyrethrins, organophosphate, and carbamate pesticides, can produce behavioral manifestations following accidental exposure...The effects of the pesticides on activity also support the hypothesis that these agents may affect the central nervous system."

Dr. J. A. Mitchell, S. F. Long 
Dept. of Pharmacology, University of Mississippi 
The Behavioral Effects of Pesticides in Male Mice 

Chlordane Causes Neurological Disorders and A.D.D. Symptoms in Adults

SOURCE: Environmental Health Perspectives, 103:690-694, 1995 

In 1987, over 250 adults and children were exposed to the pesticide chlordane when the wooden building surfaces and soil around their apartment complex was sprayed. Their exposure came from the vapors that entered into their home for the years after the chemical's application. Levels inside the homes were reported above 0.5 ug/m3 (micrograms per cubic meter).


In June-September 1994, 216 adult occupants or former residents of the apartment complex were examined by researchers at the University of Southern California School of Medicine in Los Angeles. The 109 women and 97 men were given a battery of neurological tests to determine if the low levels of chlordane in their apartments was causing any harmful effects. The tests given are considered sensitive indicators of neurotoxicity. To determine if chlordane was in fact causing neurological problems, the test scores of the chlordane exposed adults were compared to the test scores of 94 women and 68 men from Houston, known not to have been exposed to chlordane. 

Results of the testing showed many negative effects upon mental function from the low levels of air chlordane. Not only were test scores lower for reaction time, balance, and memory, but also worse scores were observed in the test checking for attention deficits (digit symbol) and all tests of mood scores including tension, depression, anger, vigor and fatigue. 

Going beyond the neurological testing, both groups were also investigated for many common symptoms and illnesses. Those which were significantly more common in the chlordane exposed group included asthma, allergies, production of phlegm, chronic bronchitis by Medical Research Council criteria, and wheezing with and without shortness of breath. Headaches and indigestion were also more common among the chlordane exposed individuals. 

In summary Dr. Kilburn and Thornton summarized their findings by stating, 

The exposure of our study group appears to be from indoor air, due to the outgassing of chlordane from the wooden surfaces of the apartment complex... Examination of subjects exposed in their homes to chlordane as compared to referent subjects showed significant, and we suggest important, impairment of both the neurophysiological and psychological functions including mood states. Accompanying these changes were significant differences in symptom frequency and in respiratory rheumatic and cardiovascular disease symptoms. The most notable changes were slowing of reaction time, balance dysfunction as revealed by increased sway speed, reduction in cognitive function, perceptual motor speed, and immediate and delayed verbal recall... The neurobehavioral impairments measured in this environmental epidemiological study were similar to those noted in patients exposed to chlordane at home. These impairments include probably irreversible dysfunction of the brain. Possible effects on trigeminal nerve-pons-facial nerve function were suggested for the first time. Confirmatory studies, including follow-up after removal from exposure, are urgently needed. Meanwhile, chlordane use should be prohibited worldwide."

CHEM-TOX COMMENT: This study should generate heightened concern because of the large number of neurological and health effects seen at chlordane air levels of above 0.5m g/m3 (typical levels for most U.S. homes) and statements by researchers that developing children are harmed more by chemicals than adults. For more information on the chlordane problem and the health effects of living in a chlordane treated home - visit the chlordane web site by clicking this link.  

Dr. Kaye H. Kilburn and John C. Thornton 
Environmental Sciences Laboratory 
University of Southern California School of Medicine, Los Angeles 

Male Infertility After Pesticide Chlordane Exposure

SOURCE: Bulletin of Environmental Contamination Toxicology, 39:434-442, 1987 

In the following study, researchers divided mice into three groups of ten mice each. Two groups were subjected to either a low or higher level of chlordane and the third group was used as a control group not exposed to any chlordane. After 30 days of daily exposure, the animals were sacrificed and the testicles were examined. The researchers stated that the chlordane exposed groups showed obvious changes to the part of the testicles where sperm development occurs (called the seminiferous tubules). Damaged tubules were present in 19% of the lower chlordane exposed animals - 31% of the higher chlordane exposed animals and only 3% in the animals not exposed to chlordane. There was also a reduction in the seminiferous tubule diameter in the higher chlordane exposed group. More details of this research can be seen at the infertility web site

Dr. K. J. Balash, M. A. Al-Omar, et al. 
Biological Research Center, Scientific Research Council, Baghdad, Iraq 

Pet Bladder Cancer Linked to Home Pesticide Use

SOURCE:  Journal of  Toxicology and Environmental Health; 28 (4). 1989. 407-414

A case-control study of household dogs was conducted to determine if exposure to sidestream cigarette smoke and chemicals in the home, use of topical insecticides, and obesity are associated with the occurrence of bladder cancer. Information was obtained by interview from owners of 59 dogs with transitional-cell carcinoma of the bladder and 71 age- and breed size-matched control dogs with other chronic diseases or neoplasms. Bladder cancer risk was unrelated to sidestream cigarette smoke and household chemical exposures. Risk was significantly increased by topical insecticide use.  When dogs were given 1-2 topical pesticide applications per year, there was a 60% increased risk of bladder cancer.  When animals were given more than 2 pesticide applications per year there was a 3.5 times increased risk for the animal developing bladder cancer (chitrend; p = .008).  This risk was enhanced in overweight or obese dogs. Further studies of this canine model may facilitate identification of specific carcinogens present in insecticides commonly used on pet animals and in the environment.

Department of Pathobiology
Purdue University School of Veterinary Medicine, West Lafayette, Indiana


Pesticides Blamed for Higher Cancer Rates

SOURCE: Winnipeg CBC News - June 7, 2004

WINNIPEG - Doctors at a weekend conference in Winnipeg say there is a disturbing trend when it comes to the rising rate of certain cancers. They say pesticides are to blame for the increase especially in childhood cancers.  Steve Rauh chairs the environment committee for the Social Planning Council of Winnipeg.  He says 70 per cent of the toxins we are exposed to come from the foods we eat.  He wants to see policy changes that would encourage organic farming.  "Our department of agriculture does not provide the kind of support to organic farming that it ought to be providing," he says.  The Canadian Association of Physicians for the Environment has taken a strong position against municipalities using pesticides. It has also written papers on climate change.


Infertility Problems from Pesticide Exposure

SOURCE: Science: Thursday, June 2, 2005

Parents exposed to pesticides may be damaging their children's chance of having their own children.   The study, published in the journal Science, involved exposing rats to two common agricultural chemicals - the fungicide vinclozolin and the pesticide methoxychlorthat. Both are chemically related to natural hormones, and have been tentatively implicated in reproductive disorders in both animals and humans. When the rats gave birth, their male offspring tended to have low sperm counts and low fertility. None of that was a surprise. But what did surprise researchers was the fact that when these males did manage to reproduce, their offspring also had low sperm counts. And so did the generation after that - more than 90% of the males in each generation were affected.

If the same effect occurs in humans - a reasonable hypothesis - it could imply that keeping poisons out of the environment becomes even more important than previously realized. Michael K. Skinner, director of the University's Center for Reproductive Biology, suggests that that the new  findings on toxin damage being transmitted across generations could even help explain the dramatic rise in breast and prostate cancer in recent decades as partly due to the cumulative effect of various toxins over several generations.

Epilepsy (Seizures) Linked to Higher Blood Levels of Pesticides

SOURCE:  Pediatrics: Volume 2013, October 2013
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STOP SPRAYING INTRODUCTION: Epilepsy has gone from affecting about one-fifth of the population in the 1950's to about 1% of the population in 2015. This represents a five-fold increase over the past 60 years. In March of 2015, a family rented a condominium in the U.S. Virgin Islands. Before the family's arrival, the unit had been treated with the pesticide methyl bromide. That evening, several family members began having seizures. This represents a dramatic onset of seizures from a high level of pesticide exposure.

In an attempt to look at how lower levels of pesticides could affect epilepsy, researchers in New Delhi recruited 20 children (ages 2 to 12) who currently had idiopathic seizures. By definition, idiopathic epilepsy is where a child has seizures but there is no observed structural brain abnormalities. Another 20 children of the same ages who did not have epilepsy were also included in the study as a control group.

Researchers measured the blood of all 40 children for the pesticides DDT, DDE, endosulfan, aldrin, dieldrin, and the hard to pronounce pesticide hexachlorocyclohexane (let's call it HCH for short). While the pesticide levels were the same in both groups for DDT, dieldrin and other pesticides, it was found that children suffering from seizures had significantly higher levels of several pesticides when compared to the "normal" children not experiencing seizures.

For example, in the non-seizure children, blood levels of the pesticide endosulfan averaged only .89 parts per billion (ppb) while children with epilepsy averaged about 60% higher at 1.42 ppb. In regards to the pesticide "Gamma-BHC" (used in agriculture and head lice treatments) - the control children averaged 2.70 ppb and the seizure children had 3 times higher levels at 8.90 ppb.

The researchers concluded by stating:

Higher levels of ß and "y" and total HCH point towards organochlorine pesticides having some association with idiopathic seizures in this age group.... To the best of our knowledge, this is the only study, where high serum levels of ß, "y" and total HCH, and endosulfan have been found to be possibly associated with idiopathic seizures in children. The study raises the concern of an association or a possible causation between environmentally acquired raised serum OCP levels and seizures of unproven etiology in children. 

Department of Pediatrics, University College of Medical Sciences, Delhi, India
Department of Biochemistry, University College of Medical Sciences, Delhi, India

Epilepsy tied to Defective Blood Brain Barrier

SOURCE:  Epilepsia, Vol. 47(11):1761-74, November 2006
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The blood brain barrier works to keep toxic chemicals out of the brain. It has been shown to be defective in a number of mental illnesses including Alzheimer's and Psychosis.

Scientists at the Cleveland Clinic Foundation, Department of Neurological Surgery stated that in research looking for new ways to deliver drugs to the brain, it was discovered that failure of the blood brain barrier can lead to seizures.

STOP SPRAYING COMMENT: As previous summaries in our report have shown that some pesticides can damage the blood brain barrier, this makes a plausible connection for the ability of pesticides to cause seizures or epilepsy (through disruption of the blood brain barrier.)

Cleveland Clinic Foundation
Department of Neurological Surgery
Cerebrovascular Research, Ohio

Autoimmunity - Immune System Damage from the Pesticide Dursban

SOURCE: Archives of Environmental Health, 48(2):89-93, March/April 1993
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Autoimmune disorders include arthritis, diabetes type 1, lupus, multiple sclerosis and others. These conditions occur when the immune system becomes "ignorant" and mistakenly attacks healthy cells in the body. Normally, this problem is avoided by proper function of the thymus gland (above and behind the heart) which works to filter and remove autoimmune cells.

Although the pesticide dursban was banned back in 2002, people can still be exposed to the chemical if living in homes that received soil-drench termite treatments prior to the ban or currently live near agriculture (where it is still used under the name Lorsban).

In this study, by the Department of Health Science at California State University, 12 individuals - including a teacher, six housewives, a retail owner, a musician and an engineer, were studied for 1 to 4.5 years after they became ill when their home or place of employment was treated with dursban. The researchers looked for any abnormalities in immune system function. Immediately following each patient's exposure to the pesticide, common complaints included an initial flu-like illness followed by chronic complaints of fatigue, headaches, dizziness, loss of memory, upper and lower respiratory symptoms, joint and muscle pain and gastrointestinal disturbances. The subjects were found to have elevated numbers of CD26 white blood cells and a higher rate of autoimmune problems, when compared to two other control groups. Autoantibodies (antibodies that mistakenly attack healthy cells) were found against smooth muscle, parietal cell, brush border, thyroid gland, myelin, and also antibodies that attacked the main proteins in the nucleus of the cells (called ANA).

83% of the people exposed to dursban had autoantibodies in their blood while only 15% for people not exposed had autoantibodies. 50% of the pesticide exposed people were also found to have two or more autoantibodies in comparison to only 4% for the non-exposed group. 

In conclusion the researchers stated, 

"the presence of several different types of autoantibodies, e.g., antimyelin, antismooth muscle, anti brush boarder, and antimicrosomal, indicates that generalized tissue injury has occurred. Moreover, these identical observations have been made in additional chlorpyrifos patients (research in progress). Thus, chlorpyrifos (Dursban), as used in pesticide spray, should be examined more closely as a probable immunotoxin."

Jack D. Thrasher Ph.D., Roberta Madison, Alan Broughton 
Department of Health Science, California State University