Nervous System Effects

Pregnant Mothers Exposed to Insecticides More Likely to Have Children Who Develop ADHD   (Beyond Pesticides, July 11, 2019) '  The pesticides investigated by researchers were breakdown products of the organophosphate chlorpyrifos, and the synthetic pyrethroid class of insecticides. The residue of these chemicals are frequently detected on conventional, industrially farmed food products. Although chlorpyrifos is banned from residential use in the U.S., most household bug sprays such as RAID contain high amounts of synthetic pyrethroids.  Among the 948 pregnant Danish women tested, 90% had some level of chlorpyrifos metabolites (3,5,6-trichloro-2-pyridinol) detected in their urine, and 94% were positive for the generic pyrethroid metabolite (3-phenoxybenzoic acid). Concentrations of both chlorpyrifos and pyrethroid breakdown products in maternal urine samples above the median detection rate for the study corresponded with a 98% increase in odds of their children having ADHD scores in the 90th percentile, a strong predictor for an ADHD diagnosis.

Pyrethroid Pesticide Use Increases Rates of ADHD in Adolescent Boys in New Study (Beyond Pesticides June 4, 2015). "Boys with detectable urinary 3-PBA, a biomarker of exposure to pyrethroids, are three times as likely to have ADHD compared with those without detectable 3-PBA. Hyperactivity and impulsivity increased by 50 percent for every 10-fold increase in 3-PBA levels in boys". The use of pyrethroids has also "been linked to learning problems, and adverse behavioral and emotional development in children". 

Attention-Deficit/Hyperactivity Disorder and Urinary Metabolites of Organophosphate Pesticides. Maryse F. Bouchard et al , Pediatrics; originally published online May 17, 2010. Children with more organophosphates marker in their urine (especially dimethyl alkylphosphate (DMAP)) were more likely to be diagnosed as having ADHD. These findings support the hypothesis that organophosphate exposure, at levels common among US children, may contribute to ADHD prevalence.

see also autism

Environmental toxicants and autism spectrum disorders: a systematic review    (D A Rossignol et al, Transl Psychiatry. 2014 Feb; 4(2): e360)  link to full study. I am only reportign the pesticide data here.  re: gestational exposure: "This model identified two peaks of developmental vulnerability, one that extended from 38 days before fertilization to 163 days following fertilization and a second postnatal peak ranging from 346 to 529 days post fertilization."  Exposure to organochlorine pesticides (specifically dicofol and endosulfan) and the organophosphates in general and the insecticide chlorpyrifos in particular were linked to development of autism spectrum disorder. '... re: childhood exposure: the evidence linking pesticide exposure in ASD does not appear as strong during childhood as during the gestational period particularly because there are fewer studies examining this factor during childhood; therefore, additional studies are warranted.'

Prenatal and infant exposure to ambient pesticides and autism spectrum disorder in children: population based case-control study  (Ondine S von Ehrenstein et al, BMJ, 20 March 2019)  11 high use pesticides were selected for examination. Risk of autism spectrum disorder was associated with prenatal exposure to glyphosate, chlorpyrifos, diazinon, malathion, avermectin, and permethrin. For autism spectrum disorder with intellectual disability, estimated odds ratios were higher (by about 30%) for prenatal exposure to glyphosate, chlorpyrifos, diazinon, permethrin, methyl bromide, and myclobutanil; exposure in the first year of life increased the odds for the disorder with comorbid intellectual disability by up to 50% for some pesticide substances. Also see Autism Linked to Wide Range of Commonly Used Pesticides (Beyond Pesticides, March 27, 2019)  for more in depth analaysis.

Aerial Mosquito Spraying Linked to Elevated Autism Rates  (Beyond Pesticides, June 15, 2017) Communities exposed to frequent aerial spraying for mosquito control experience elevated rates of autism diagnoses, according to new research. The study identifies the frequent use of synthetic pyrethroid insecticides, which are linked to neurocognitive and behavioral impacts, among other health effects...The study finds that the zip codes with frequent aerial pyrethroid exposure are 37% more likely to have higher rates of childhood developmental delays and autism spectrum disorder. The researchers acknowledge that the study establishes a correlational, not a causal, link between pyrethroid exposure and autism/developmental disorders, it adds to a growing body of research demonstrating an exposure-effect relationship between the two.

Banned Chemicals Linked to Increased Autism Risk (Beyond Pesticides, August 24, 2016) Researchers at Drexel University report that higher levels of some organochlorine compounds during pregnancy are associated with autism spectrum disorder (ASD) and intellectual disability (ID). The organochlorine compounds under study have long been banned in the U.S., and include pesticides like DDT, underscoring how pervasive and persistent these chemicals are, and their continued impact on human health. The research is reported in the study Polychlorinated Biphenyl and Organochlorine Pesticide Concentrations in Maternal Mid-Pregnancy Serum Samples: Association with Autism Spectrum Disorder and Intellectual Disability, 

Autism risk higher near pesticide-treated fields, study says Exposure of pregnant women to organophosphates and also for the first time to pyrethroids linked to autism risk. The study also reported an increased risk of developmental delays, but not autism, in kids whose moms lived near fields where carbamates, including methomyl and Sevin, were applied. Good review of autism risks to put those in perspective. June 23, 2014 

Autism Explained: Synergistic Poisoning from Aluminum and Glyphosate - Stephanie Seneff. Video (2 hours 8 minutes) May 28, 2014

Childhoods lost: disabilities and seizures blight India's endosulfan victims (The Guardian, 15 February 2017)  Likely over 5000 children affected. Endosulfan is an acutely toxic organochlorine insecticide. SNAP Comment: Well, this is not only a Kerala. India problem. where it was aerially sprayed on the cashew crop. 14 Endosulfan formulations were historically registered in Canada and two, THIONEX EC (ENDOSULFAN) COMMERCIAL INSECTICIDE and THIONEX 50W WSP WETTABLE POWDER INSECTICIDE were still legally sold until the end of 2016. This means they may still be in use because the Pesticide Act and regulations control sales, not use. I am sure there have been health effects but, until recently, the PMRA did not collect them or consider them in pesticide registration. The system currently set up only requires manufacturers (not MDs) to disclose pesticide health effects. To report a pesticide 'incident' or check go to adverse effects reporting 

Study Reveals: Organophosphate Pesticides Cause Lasting Damage to Brain and Nervous System (Beyond Pesticides, December 10, 2012)   Low-level exposure had significant detrimental effect on working memory and information processing. 

Pesticides may damage brain     (October 24, 2008. sources: Globe and Mail, PANNA) Children are especially at risk. Pesticides that could be damaging included organophosphates (OPs), carbamates, pyrethroids, ethylenebisdithiocarbamates and chlorophenoxy herbicides (such as 2,4-D, mecoprop and dicamba commonly used on lawns)

 Pesticide Exposure Damages Nervous System, Brain and gastro-intestinal tract .(July 2006)

Inhaled Pollutants May Inflame More Than the Lungs (2010)  

(By Janet Raloff, Science News, Web edition: May 7, 2010, Print edition: May 22, 2010; Vol.177 #11 (p. 16)) 

Scientists have known that air pollution can impair airways and blood vessels. The emerging surprise is what it might do to the brain. Increasingly, studies have been highlighting inflammation-provoking nanopollutants as a potential source of nerve cell damage. PAULE's NOTE: Research into Multiple Chemical Sensitivities has long indicated that pollutants crossed the blood-brain barrier. It has also shown through SPECT and other brain scans that areas of the brain can shut down upon exposure to substances one is sensitive to, In other words, blood circulation to the brain would be shut down or reduced for hours at a time. Research in nano-particles has recently shown that they are small enough to enter cells. In the meantime, other research indicated that it's not only the size of a particle that is important but also what it is. Pesticide applications often produce very small particles in the nano-particle range. Nothing surprising for those of us who have MCS and have been following the research. I am however horrified to see these measurable effects widespread to all children exposed to polluted air. Full article:  http://www.sciencenews.org/view/feature/id/58906/title/Destination_brain. Information accessible to paid subscribers only.Try accessing a library. 

see also Exposure to Pesticides linked to ALS (Beyond Pesticides, May 16, 2016), pesticides in food and glyphosate

Despite Damning Scientific Evidence, EPA Dismisses Link Between Parkinson’s and Exposure to the Herbicide Paraquat  (Beyond Pesticides, October 17, 2019)    'In response to this growing body of literature, EPA conducted an epidemiological evaluation of published studies on the link between paraquat and Parkinson’s. But, in a similar manner to how the agency conducted its epidemiological evaluation of pyrethroids, EPA made broad statements dismissing scientific evidence as insufficient...  On the link between paraquat and Parkinson’s, “The data is overwhelming” said Samuel M. Goldman, MD, an epidemiologist in the San Francisco Veterans Affairs health system to the New York Times. “I’m not a farmer, I don’t need to kill weeds, but I have to believe there are less dangerous options out there.”   An EPA environmental review conducted as part of the reregistration process found evidence of significant reproductive harm to small mammals, and determined that songbirds may be exposed to levels well beyond lethal concentrations known to cause death. Threats to mammals and songbirds are particularly concerning in light of significant declines in these animal groups.'   SNAP Comment: There are still 3 paraquat products registered by Syngenta in Canada, including one commercial product, Gramoxone, re-registered in 2018 until 2013.

New Developments in the Link Between Parkinson’s and Pesticides  (Beyond Pesticides, December 20, 2018)  'Lectin, which is often found in healthy foods like raw vegetables, eggs, and dairy, combined with paraquat in the gut and triggered the formation of a misfolded protein called alpha-synuclein, a foreign agent that likely plays a role in the development of Parkinson’s. Alpha-synuclein travels from the gut to the brain via the vagus nerve.  Any herbicide implicated in the development of a disease, which is expected to double in diagnosis over the next 20 years, raises serious questions about compliance with safety standards. A large body of scientific studies strongly implicates this chemical in the development of Parkinson’s disease. Earlier this year, research published in the journal Cell Reports implicated paraquat for its ability to create senescent cells that cause inflammation in the brain.'

Parkinson's linked to gut bacteria  (Robert Ferris, CNBC, 1 December 2016) The scientists published their findings Thursday in the journal Cell. 'The germ-free mice were still overproducing alpha-synuclein, but their brain cells were not accumulating the protein. The germ-free mice showed fewer symptoms and performed better on a series of motor skills tests meant to model the kinds of tests given to human patients.' More experiments determined that what gut flora produces affects the development of Parkinson's. SNAP Comments: Several pesticides and other toxins have been linked to Parkinson's in the past. Now we also know from research that some pesticides, including glyphosate, affect the health of gut bacteria, usually suppressing good flora and promoting bad. The effects of a pesticide on gut flora are not required tests for pesticide registration. Of course use of antibiotics and what one eats is also important, but remember that people eating conventional food ingest several pesticides on a daily basis. Evidence is accumulating that gut flora is extremely important to the maintenance of health and the development of many diseases. I sincerely hope that more pesticide and toxins regularly found in our environment start being tested for their effect on gut flora. That research would provide a mechanism of action.

Pesticides and Parkinson's: Further Proof of a Link  Jan. 3, 2013. UCLA researchers have discovered a link between Parkinson's and the pesticide benomyl, whose toxicological effects still linger some 10 years after the chemical was banned by the U.S. EPA and Canada...A new pathway was discovered. The pesticide prevents an enzyme called ALDH (aldehyde dehydrogenase) from keeping a lid on DOPAL, a toxin that naturally occurs in the brain. Benomyl was widely used in the U.S. for three decades until toxicological evidence revealed it could potentially lead to liver tumors, brain malformations, reproductive effects and carcinogenesis. It was banned from the US in 2001 and at the end of 2003 in Canada.

Agent Orange Tied to Parkinson’s in Vietnam Vets (July 2009)

Occupational Use of 2,4-D, Permethrin Triple the Risk of Parkinson’s Disease   (Beyond Pesticides, Sept.16,2009)

Gene Variants and Pesticide Exposure Increase Risk of Parkinson’s Disease   (Beyond Pesticides, January 11, 2010) The findings show that study participants with two copies of gene variant have a significantly increased risk of developing Parkinson’s disease when exposed to certain organophosphate pesticides used in agriculture...Individuals with the variant MM PONI1-55 genotype that are exposed to organophosphates exhibit more than twice the risk of Parkinson’s disease compared to carriers of wildtype or heterozygous genotype and no exposure. ( diazinon, chlorpyrifos)

New evidence linking pesticides, genes & Parkinson's (PanUps,  May 14, 2009) "Exposure to commonly used agricultural pesticides may increase the risk of developing Parkinson's disease, particularly among people who have certain gene types," reports Environmental Health News. Summarizing the new research, EHN notes: "The degenerative nerve disease can develop when dopamine levels in the brain are lower than normal. Without pesticide exposures, susceptible gene variants alone were not sufficient to increase risk. The increased risk to Parkinson's required both susceptible genes and pesticide exposure." The full article (PDF) is available from Environmental Health Perspectives.

Residential Exposure to Agricultural Pesticides Increases Risk to Parkinson’s Disease. (Beyond Pesticides, March 16, 2009) Posted in California, Maneb, Paraquat, Parkinson's :exposure to both pesticides within 500 meters of an individual’s home increases the risk of developing Parkinson’s by 75 percent. For individuals 60 years of age or younger at the time of diagnosis, there is a more than four-fold increase in risk of the disease when exposed to a combination of maneb and paraquat

Gene-Pesticide Interactions Linked to Parkinson’s Disease (Beyond Pesticides, March 2, 2009) Posted in Maneb, Paraquat, Parkinson's

Pesticides may be blamed for rise of Parkinson' in Manitoba: Study

Pesticides Trigger Parkinson Disease by Kagan Owens. (Pesticides and You. Vol 28, no 1, Spring 2008. Beyond Pesticides, p.14) Many types of insectides are toxic to the nervous system.The better-known classes such as the oganochlorines (OCs e.g. endosulfan), organophosphates (OPs: e.g.malathion, chlorpyrifos), the carbamates (e.g. carbofuran), synthetic pyrethroids (e.g. permethrin, resmethrin). some herbicides such as 2.4-D are also toxic to the nervous system. This article has a list of specific pesticides linked to Parkinson Disease.

Parkinson's Disease (Beyond Pesticides)