(My Cul-de-Sac’s Sad but True Pyrethroid Story)

by Dr. Lindsey Berkson

I called my next-door neighbor in my tight neighborly cul-de-sac, Charette Cove North, to ask Beth for the name of their bug guy that she said used only natural products. Tall burly Gerald came over wearing a clean shirt that had printed over the chest pocket, “Natural Answers for Nasty Bugs.” What were these natural answers? Pyrethroids. Gerald explained these were safe natural versions of extracts of the Chrysanthemum plant’s own bug-fighting pyrethrins. The natural flower extract kills bugs, and Gerald proudly exclaimed that this version was completely natural, safe, and effective. Gerald reassured me that all the families on my cul-de-sac had been using him and his safe products for the past decade.

But I knew that many of the kids that lived in my tiny community were fighting major battles—from anger control to learning disabilities to autoimmune diseases. I rise each morning to sleuth the medical literature along with my morning cup of Joe. In the back of my mind I remembered reading a not-so-nice article about these chemicals and kid’s brains.

So I invited Gerald to come into my home. We sat on benches at the kitchen counter while I opened up my trusty Mac. Being a geek on rhoids, I clicked to PubMed, the NIH powerhouse of peer-reviewed abstracts that are available to all of us online for free. After typing “pyrethroids” into the search bar, it took less than 10 seconds for a whole list of very scary articles to show up.

I read the name of the articles and the authors’ conclusions out loud to Gerald.

The message was loud and clear: pyrethroids are dangerous, especially to kids. They act as hormone-altering chemicals (often called endocrine disruptors). This class of pesticides affects the brain. Kids, especially male children, with regular exposure to pyrethroids have more attention deficit hyperactivity disorder (ADHD), much more difficulty controlling their impulses, and many more negative emotions like anger, as compared to kids not exposed to pyrethroids. When pyrethroids are sprayed inside the home, kids inhale the aerosolized chemical. When pyrethroids are sprayed outside on home gardens and these veggies are eaten, the same issues arise.

In 2015, two studies came out showing the dangers of pyrethroids, one on animals and the other on humans. Exposing mice to pyrethroids during developmental periods when their brain and nervous system were rapidly growing (from birth toward what would be the equivalent of mice teenage-hood) these rodents developed ADHD-like behavior. The authors concluded that these chemicals are not safe for human kid brains. This study was published by a group of impressive and prestigious institutions (The Department of Environmental and Occupational Medicine and Environmental and Occupational Health Sciences Institute, Rutgers; Robert Wood Johnson Medical School, Rutgers; The State University of New Jersey; Center for Neurodegenerative Disease, School of Medicine, and Department of Environmental and Occupational Health; Rollins School of Public Health, Emory University; Department of Physiology and Pharmacology, Wake Forest University Health Sciences; Department of Chemistry, Wayne State University; and Department of Environmental Medicine, University of Rochester Medical Center).

All these heavy hitters gave huge warnings that pyrethroids are not good for our kid’s brains.

It has also been shown that when women are pregnant and exposed to pyrethroids in the home or via the veggies she eats, this can adversely affect the development of her infant. Behavioral issues can start to show up with the infant is about a year and a half old.

Another study was done on 687 eight to fifteen-year-olds from the National Health and Nutrition Examination Survey in the early 2000s. This study checked the children for a breakdown product of the pesticide in the kids’ urine (3-phenoxybenzoic acid, nicknamed 3-PBA). If a child was exposed to pyrethroids and his body processed the pesticide, the breakdown metabolite could be measured in the urine; it’s a clear-cut marker of exposure. The study also checked whether or not the kids were identified as having ADHD.

Children with more pyrethroid exposure, proven by their urinary metabolite markers, were twice as likely to have ADHD compared to children who did not have the metabolite, meaning they had not been exposed to pyrethroids. The more exposure, the more the kids had hyperactive-impulsivity issues. It was dose-dependent. To be very clear, this means that the more bug killer these kids were exposed to, the less control they had over their behavior. Boys were more vulnerable to this chemical than girls.

Once again, the list of authors was remarkable (Cincinnati Children’s Hospital Medical Center; Rutgers Robert Wood Johnson Medical School and Environmental and Occupational Health Sciences Institute; Department of Environmental and Occupational Medicine, University of Rochester School of Medicine and Dentistry; Department of Neurology, Center for Human Experimental Therapeutics, Brown University School of Public Health; Simon Fraser University; Child & Family Research Institute; BC Children’s Hospital; Cincinnati Children’s Hospital Medical Center, Division of Behavioral Medicine and Clinical Psychology; and the Cincinnati Children’s Hospital Medical Center).

This long list of authors concluded that pyrethroids are dangerous environmental toxicants for our kids.

I read these abstracts out loud to Gerald. He got quiet. Then this large African-American clean-cut gentleman put his head on his arms on the counter. He sighed painfully. As he slowly sat up, I saw tears in the corners of his eyes.

“They reassure us at our yearly conferences that these chemicals are completely safe. They never told us any of this! My own son has impulse control issues and ADHD!”

The massive number of authors are cautioning us that there is tremendous concern that these pesticides sprayed inside American homes and on gardens and food fields are a serious threat to our kids’ brains and behavior. Have you heard about this? What’s inside your homes?

Pyrethroid pesticides cause abnormalities in the dopamine system. They reproducibly produce ADHD syndromes in animal models, as well as having been demonstrated in human children.

Pyrethroids account for more than 30 percent of global insecticide use. These chemicals are endocrine disruptors. They interfere with the body’s hormones. They interfere with your kid’s hormones. Hormones rule the brain. When your child’s hormones are disrupted, their thinking and emotions can turn bizarre. Their ability to control their emotions lessens in comparison to the stress they experience from their out-of-control emotions.

New research takes the pyrethroid dangers further. Now pyrethroid pesticides are being shown to speed up puberty in boys. When human milestones of reproduction are artificially altered by toxic exposure, this is a canary in the mine suggesting that we as a human race are facing serious threats. We have been seeing young girls who are going through puberty earlier and aging women who are going through peri- and post-menopause earlier. In Puerto Rico, female infants have been documented as showing breast buds at six months of age. Earlier hormonal maturity creates increased vulnerability for current and future diseases. Earlier puberty is linked to mental health issues such as behavioral difficulties and problems with emotional and social adjustment. It is linked to stunted growth. Earlier puberty is also linked to a higher risk of adult cancers, testicular in males and breast and ovarian in females. The list of issues is probably going to grow as more research unfolds.

Pyrethroid exposure in young boys puts them at huge risk to go through puberty prematurely. Is this going to happen to your son?

Today’s boys now mature into adults between 9 and 10 years old, two years earlier than male puberty occurred decades ago. This data is from the Hormone Health Network reports and research run by Dr. M. E. Herman-Giddens.

Pyrethroids are a newly recognized environmental contributor to this trend. In a study of 463 Chinese boys, aged 9 to 16, only a small exposure to pyrethroids was associated with a significant increase in male hormones that initiate and control the production of testosterone in males. The more exposure to pyrethroids, the greater the risk of earlier male genital development, with heavier exposures increasing the risk by 73 to 110%.

In mice exposed to cypermethrin, a type of pyrethroid, at levels similar to what humans are exposed to when homes are sprayed by companies like Gerald’s, the animals’ experienced accelerated onset of puberty.

Pyrethroids are used both indoors and outdoors to kill mosquitoes and other insects. They are sprayed on crops and home gardens. However, you and your children get most pyrethroid exposure at home. Well-meaning men like Gerald are trying to make a living by spraying the nooks and crannies of your house and they have been told by their CEOs that these chemicals are safe. If you don’t spray but your neighbors do, winds carry these chemicals onto your lawn and eventually shoes and pets carry these right on in.

You must try with all your might to have a home with less and less toxic chemical exposure. Share this article with your neighbors and submit it to your online neighborhood communities. This is critical for us to protect our next generations.

You cannot believe corporate party line when they profit by selling you their wares. Your child’s brain depends on you. It’s not worth putting their brains at risk just to have a few less bugs in your house. Google effective but truly natural alternatives. Living a lot more cleanly gives your kids a much better chance at a healthier future.

Live at though your kid’s brain depended upon it.

I recently heard that Gerald has started his own completely healthy bug elimination business.

Knowledge is power.

Please share this foreword.




FASEB J. 2015 May;29(5):1960-72. Epub 2015 Jan 28. Developmental pesticide exposure reproduces features of attention deficit hyperactivity disorder.

Int J Environ Res Public Health. 2017 Jan 8;14(1). pii: E52. Maternal Exposure to Pyrethroid Insecticides during Pregnancy and Infant Development at 18 Months of Age.

Environ Health. 2015 May 28;14:44. Association of pyrethroid pesticide exposure with attention-deficit/hyperactivity disorder in a nationally representative sample of U.S. children.

Pediatrics. 2012 Nov;130(5):e1058-68. Secondary sexual characteristics in boys: data from the Pediatric Research in Office Settings Network.

The Endocrine Society. “Pyrethroid pesticide exposure appears to speed puberty in boys.” Presented at the Endocrine Society’s 99th annual meeting in Orlando, Fla. April 2017.

J Adolesc Health. 2013 Jul;53(1):118-24. Early puberty and childhood social and behavioral adjustment.

Your Son’s Brain & Emotions Are Under Toxic Attack