Toxic Chemicals

The Role of Heavy Metals and Environmental Toxins in Psychiatric Disorders

James Greenblatt, MD

Every day we are exposed to toxins from our environment. We may ingest lead and copper from drinking water, phosphate from processed food and soda, various synthetic chemicals from plastic food containers, and pesticides from fruits and vegetables. Both natural heavy metals and man-made chemicals disrupt hormones and brain development. The brain, especially the developing brain, is very vulnerable to contaminants because of its large size (relative to total body weight) and its high concentration of fats which serve as a reservoir for toxicants to build up. This article will explain the role that heavy metals and environmental toxins play in ADHD.

In January 2016, President Obama declared a state of emergency in Flint, Michigan where thousands of residents were exposed to high levels of lead in their drinking water. The corrosive water from the Flint River caused lead from old water pipes to leach into the water supply, putting up to 12,000 children at risk of consuming dangerous levels of lead. Lead poisoning can cause irreversible brain damage and even death, and growing children are especially susceptible to its poisonous effects. Even low blood lead levels reduce IQ, the ability to pay attention, motor function, and academic achievement.

Blood lead levels in children have plummeted since the US phased out the use of leaded gas and paint in the 1970’s. Still, 24 million homes in the US contain deteriorated lead paint and elevated levels of lead-contaminated dust. Soil contains lead from air that settled during our previous industrial use. Old toys and toys from China may contain lead-based paint as well. Again, children are especially at risk of lead poisoning in these environments because they are likely to put their contaminated toys or hands in their mouth.

Since lead poisoning causes cognitive, motor, and behavioral changes, it is not surprising that it also causes ADHD. Lead exposure is estimated to account for 290,000 excess cases of ADHD in US children (Braun et al., 2006). A study on 270 mother-child pairs in Belgium found that doubling prenatal lead exposure (measured in cord blood) was associated with a more than three times higher risk for hyperactivity in boys and girls at age 7-8 (Sioen et al., 2013). A larger study on almost 5,000 US children aged 4-15 found children with the highest blood lead levels were over four times as likely to have ADHD as children with the lowest blood lead levels (Braun et al., 2006).

MRI scans from participants of the Cincinnati Lead Study had striking results: childhood lead exposure was associated with brain volume loss in adulthood. Individuals with higher blood lead levels as children had less gray matter in some brain areas. The main brain region affected was the prefrontal cortex which is responsible for executive function, behavioral regulation, and fine motor control (Cecil et al., 2008).

The CDC has set a blood lead level of 5 µg/dL as the reference value to identify children who require case management. However, many studies have shown lead levels <5 μg/dL still pose problems. For instance, researchers assessing 256 children aged 8-10 concluded, “even low blood lead levels (<5 μg/dL) are associated with inattentive and hyperactivity symptoms and learning difficulties in school-aged children” (Kim et al., 2010).

Copper is an essential trace mineral we must consume from our food supply. It is found in oysters and other shellfish, whole grains, beans, nuts, and potatoes. Like lead, copper can leach into the water supply when copper pipes corrode. One of copper’s roles in the body is to help produce dopamine, the neurotransmitter that provides alertness. However, too much copper creates an excess of dopamine leading to an excess of the neurotransmitter norepinephrine. High levels of these neurotransmitters lead to symptoms similar to ADHD symptoms: hyperactivity, impulsivity, agitation, irritability, and aggressiveness. In children with excess copper, stimulant medications don’t work as well and tend to cause side effects (agitation, anxiousness, change in sleep and appetite). Most ADHD medications work by increasing levels of dopamine, intensifying the effects of excess copper. In addition, excess copper blocks the production of serotonin, a mood-balancing neurotransmitter. This triggers emotional, mental, and behavioral problems, from depression and anxiety to paranoia and psychosis.

The neurotoxic effects of excess copper are well known and a few studies have assessed copper’s role in ADHD symptoms. When researchers compared copper levels in 58 ADHD children to levels in 50 control children, they observed that copper levels were higher in ADHD children. ADHD children also had a higher copper-to-zinc ratio that positively correlated with teacher-rated inattention (Viktorinova et al., 2016). Researchers in Belgium measured the heavy metal exposure of 600 adolescents aged 13-17. They found that an increase in blood copper was associated with a decrease in sustained attention and a decrease in short-term memory. This held true even though this population had normal copper levels (Kicinski et al., 2015). In a randomized controlled trial on 80 adults with ADHD, lower baseline copper levels were associated with better response to treatment with a vitamin-mineral supplement. Among those in the highest copper tertile, only 35% were responders compared to 77% in the middle copper tertile (Rucklidge et al., 2014).

Phosphate is a charged particle (an electrolyte) that contains phosphorus. Phosphorus is the second most abundant mineral in the body (the first is calcium). Phosphorus is a building block for bones and about 85% of total body phosphorus is found in the bones. Deficiencies are rare because phosphorus is naturally abundant in protein-rich foods like meat, poultry, fish, eggs, milk, and milk products as well as in nuts, legumes, cereals, and grains. Although phosphorus is an essential nutrient, too much can be problematic. The phosphate content of processed foods is much higher than that of natural foods, because phosphates are commonly used as additives and preservatives in food production. Our daily intake of phosphate food additives has more than doubled since the 1990’s (Ritz et al., 2012). Phosphorus, especially the form found in processed meats, canned fish, baked goods, and soda is quickly absorbed into the bloodstream so levels can rise rapidly.

Phosphorus reduces the absorption of other vital nutrients, many of which ADHD children are deficient in to begin with. For instance, too much phosphorus can lower calcium levels. High phosphorus coupled with low calcium intake leads to poor bone health. The typical American diet contains two to four times more phosphorus than calcium and soda is often a major contributor to this imbalance. In the body, phosphorus and magnesium bind together, making both minerals unavailable for absorption. This is most apparent when magnesium consumption is low and intake of phosphorus is high. Researchers have found that adding Pepsi to men’s diet for two consecutive days causes their blood phosphate levels to increase and their magnesium excretion to decrease (Weiss et al., 1992).

In the 1990’s, German pharmacist Hertha Hafer discovered that excess dietary phosphate triggered her son’s ADHD symptoms. Within her book, The Hidden Drug, Dietary Phosphate: Cause of Behavior Problems, Learning Difficulties and Juvenile Delinquency, she presents a low phosphate diet as a treatment for ADHD. A low phosphate diet led to dramatic improvements in her son’s behavior, well-being, and school performance, rendering medication unnecessary. Her family’s ADHD problem was resolved and her son had no further problems as long as he avoided high phosphate foods. Hafer finds that children with mild ADHD can improve simply by removing processed meats and phosphate-containing beverages like soda and sports drinks from their diets (Waterhouse, 2008).

Everyday plastic products contain hormone-disrupting chemicals, such as Bisphenol A (BPA) and phthalates, that can migrate into our body and affect the brain and nervous system. These environmental toxins bind to zinc and deplete zinc levels in the body. Phthalates are synthetic chemicals used to make plastics soft and flexible. Phthalates are used in hundreds of consumer products and humans are exposed to them daily though air, water, and food. Di(2-ethylhexyl) phthalate (DEHP) is the name for the most common phthalate. It can be found in products made with plastic such as tablecloths, floor tiles, shower curtains, garden hoses, swimming pool liners, raincoats, shoes, and car upholstery. Based on animal studies, the Environmental Protection Agency (EPA) has classified DEHP as a “probable human carcinogen.” Such studies have shown that DEHP exposure affects development and reproduction.

Multiple studies have linked phthalates with ADHD. Researchers assessed the urine phthalate concentrations and ADHD symptoms in 261 children aged 8-11. ADHD symptoms (inattention and hyperactivity/impulsivity), rated by the children’s teachers, were significantly associated with DEHP metabolites (breakdown products) (Kim et al., 2009).

Prenatal phthalate exposure is associated with problems in childhood behavior and executive functioning. Third-trimester urines from 188 pregnant women were collected and analyzed for phthalate metabolites. Their children were assessed for cognitive and behavioral development between the ages of 4 and 9. Phthalate metabolites were associated with worse aggression, conduct problems, attention problems, depression, externalizing problems, and emotional control (Engel et al., 2010).

Exposure to DEHP in pediatric intensive care units (PICU) is associated with attention deficits in children. In the hospital, DEHP can be found in and can leach from medical devices such as catheters, blood bags, breathing tubes, and feeding tubes. Researchers in Belgium measured levels of DEHP byproducts in the blood of 449 children aged 0-16 while they were staying in a pediatric intensive care unit. Four years later, the children’s neurocognitive development was tested and compared to that of healthy children. The researchers found that all medical devices inserted into the body actively leached DEHP. Predictably, hospitalized children had very high levels of DEHP byproducts throughout their stay in the intensive care unit. A high exposure to DEHP was strongly associated with attention deficit and impaired motor coordination four years after hospital admission. Phthalate exposure from the PICU explained half of the attention deficit in post-PICU patients (Verstraete et al., 2016).

BPA is another problem chemical which is found in food and drink packaging. Exposure to BPA may be related to behavior problems in children. A 2016 nationwide study of 460 children aged 8-15 found children with higher urinary levels of BPA had over five times higher odds of being diagnosed with ADHD (Tewar et al., 2016). In another study, researchers measured BPA concentration in urine samples from women at 27 weeks of pregnancy then assessed the behavior of their children at age 6-10. There was a significant positive association in boys between prenatal BPA concentration and internalizing and externalizing behaviors, withdrawn/depressed behavior, somatic problems, and oppositional/defiant behaviors. Researchers speculated that BPA may have disrupted maternal thyroid or gonadal hormones which are critical to proper brain development (Evan et al., 2014).

In addition to heavy metals and plasticizers, pesticides can cause ADHD symptoms. The American Academy of Pediatrics notes, “Children encounter pesticides daily in air, food, dust, and soil. For many children, diet may be the most influential source. Studies link early-life exposure to organophosphate insecticides with reductions in IQ and abnormal behaviors associated with ADHD and autism” (Roberts & Karr, 2012).

Among pesticides, insecticides may be the most harmful to humans. Insecticides were first developed during World War II as nerve gases. They work by targeting and destroying acetylcholinesterase, an enzyme that controls the neurotransmitter acetylcholine which plays a role in attention, learning, and short-term memory. In one study of 307 children aged 4-9, researchers found that lower acetylcholinesterase activity in boys was linked to a four times greater risk of poor attention and executive function and a six times greater risk of memory and learning problems (Suarez-Lopez et al., 2013). Organophosphates (OPs) are a common type of insecticide that target the nervous system. Forty different types of organophosphates are in use in the United States.

Scientists in California studied 320 mothers and their children. They evaluated urinary levels of metabolites of OPs when the mothers were pregnant. Then when the children were 3- and 5- years old, they were evaluated for ADHD. At both time points, levels of prenatal OP metabolites were positively associated with attention problems and ADHD. Children with mothers who had the highest levels of the OP metabolites were five times more likely to develop ADHD (Marks et al., 2010).

Even organophosphate exposure at low levels common among US children may contribute to ADHD prevalence. Researchers at Harvard University studied more than 1,000 children aged 8-15 from the general population and found that those with detectable urinary levels of an OP metabolite were nearly twice as likely to be diagnosed with ADHD (Bouchard et al., 2010).


  1. Braun et al (2006). Exposures to environmental toxicants and attention deficit hyperactivity disorder in U.S. children. Environmental Health Perspectives, 114(12), 1904-1909.
  2. Cecil et al. (2008). Decreased Brain Volume in Adults with Childhood Lead Exposure. PLoS Medicine, 5(5), PLoS Medicine, 2008, Vol.5(5).
  3. Engel et al. (2010). Prenatal phthalate exposure is associated with childhood behavior and executive functioning. Environmental Health Perspectives, 118(4), 565-71.
  4. Evans et al. (2014). Prenatal bisphenol A exposure and maternally reported behavior in boys and girls. Neurotoxicology, 45, 91-99.
  5. Kicinski et al. (2015). Neurobehavioral function and low-level metal exposure in adolescents. International Journal of Hygiene and Environmental Health, 218(1), 139-146.
  6. Kim et al. (2009). Phthalates Exposure and Attention-Deficit/Hyperactivity Disorder in School-Age Children. Biological Psychiatry, 66(10), 958-963.
  7. Kim et al. (2010). Association between blood lead levels (< 5 μg/dL) and inattention-hyperactivity and neurocognitive profiles in school-aged Korean children. Science of the Total Environment, 408(23), 5737-5743.
  8. Ritz, et al. (2012). Phosphate additives in food--a health risk. Deutsches Ärzteblatt International, 109(4), 49-55.
  9. Roberts & Karr. (2012). Pesticide exposure in children. Pediatrics, 130(6), E1765-88.
  10. Rucklidge et al. (2014). Moderators of treatment response in adults with ADHD treated with a vitamin–mineral supplement. Progress in Neuropsychopharmacology & Biological Psychiatry, 50, 163-171.
  11. Sioen et al. (2013). Prenatal exposure to environmental contaminants and behavioural problems at age 7–8years. Environment International, 59, 225-231.
  12. Suarez-Lopez et al. (2013). Acetylcholinesterase activity and neurodevelopment in boys and girls. Pediatrics, 132(6), E1649-58.
  13. Tewar et al. (2016). Association of Bisphenol A exposure and Attention-Deficit/Hyperactivity Disorder in a national sample of U.S. children. Environmental Research, 150, 112-118.
  14. Verstraete et al. (2016). Circulating phthalates during critical illness in children are associated with long-term attention deficit: A study of a development and a validation cohort. Intensive Care Medicine, 42(3), 379-92.
  15. Viktorinova et al. (2016). Changed Plasma Levels of Zinc and Copper to Zinc Ratio and Their Possible Associations with Parent- and Teacher-Rated Symptoms in Children with Attention-Deficit Hyperactivity Disorder. Biological Trace Element Research, 169(1), 1-7.
  16. Waterhouse, J.C. (2008). Issue 6. Review of the Book: The Hidden Drug, Dietary Phosphate: Causes of Behaviour Problems, Learning Difficulties and Juvenile Delinquency (2000). SynergyHN.
  17. Weiss, G. H., Sluss, P. M., & Linke, C. A. (1992). Changes in urinary magnesium, citrate, and oxalate levels due to cola consumption. Urology, 39(4), 331-333.

The Importance of Testing for Glyphosate: The World’s Most Widely Used Herbicide

by William Shaw, PhD, and Matthew Pratt-Hyatt, PhD
Director and Associate Director of The Great Plains Laboratory, Inc. 

Published in the January 2017 issue of Townsend Letter

Glyphosate is the world’s most widely produced herbicide and is the primary toxic chemical in Roundup™, as well as in many other herbicides. In addition, it is a broad-spectrum herbicide that is used in more than 700 different products from agriculture and forestry to home use. Glyphosate was introduced in the 1970s to kill weeds by targeting the enzymes that produce the amino acids tyrosine, tryptophan, and phenylalanine. This pathway (called the Shikimate Pathway) is also how bacteria, algae, and fungi produce the same amino acids. This pathway is not present in humans, so manufacturers of glyphosate claim this compound is “non-toxic” to humans. However, evidence shows there are indeed human consequences to the widespread use of this product when we consume plants that have been treated with it and animals who’ve also consumed food treated with it. 

Usage of glyphosate amplified after the introduction of genetically modified (GMO) glyphosate-resistant crops that can grow well in the presence of this chemical in soil. In addition, toxicity of the surfactant commonly mixed with glyphosate, polyoxyethyleneamine (POEA), is greater than the toxicity of glyphosate alone.1 In 2014, Enlist Duo™, a herbicide product which contains a 2,4-dichlorophenoxyacetic acid (2,4- D) salt and glyphosate, was approved in Canada and the US for use on genetically modified soybeans and genetically modified maize, both of which were modified to be resistant to both 2,4-D and glyphosate. 2,4-D, which has many known toxic effects of its own is perhaps better known as a component of Agent Orange, an herbicide used by the United States during the Vietnam War to increase aerial visibility from war planes by destroying plant growth and crops. 

Glyphosate and Chronic Health Conditions

Recent studies have discovered glyphosate exposure to be a cause of many chronic health problems. One specific scientific paper listed Roundup™ as one of the most toxic herbicides or insecticides tested.2 Exposure to glyphosate has been linked to autism, Alzheimer’s, anxiety, cancer, depression, fatigue, gluten sensitivity, inflammation, and Parkinson’s.3-4 A 54-year-old man who accidentally sprayed himself with glyphosate developed disseminated skin lesions six hours after the accident.6 One month later, he developed a symmetrical parkinsonian syndrome. Figure 1 shows the correlation between glyphosate usage and rates of autism, tracking services received by autistic children under the Individuals with Disabilities Education Act (IDEA). This data was originally collected by Dr. Nancy Swanson, along with similar data for many other chronic disorders.14 The causes for these disorders have been linked to glyphosate’s impact on gut bacteria, metal chelation, and P450 inactivation.5-6 It can enter the body by direct absorption through the skin, by eating foods treated with glyphosate, or by drinking water contaminated with glyphosate. A recent study stated that a coherent body of evidence indicates that glyphosate could be toxic below the regulatory lowest observed adverse effect level for chronic toxic effects, and that it has teratogenic, tumorigenic and hepatorenal effects that can be explained by endocrine disruption and oxidative stress, causing metabolic alterations, depending on dose and exposure time.7 

Glyphosate, Cancer, and the Microbiome

The World Health Organization International Agency for Research on Cancer published a summary in March 2015 that classified glyphosate as a probable carcinogen in humans.8 Possible cancers linked to glyphosate exposure include non- Hodgkin lymphoma, renal tubule carcinoma, pancreatic islet-cell adenoma, and skin tumors.. Studies have also indicated that glyphosate disrupts the microbiome in the intestine, causing a decrease in the ratio of beneficial to harmful bacteria.9 Thus, highly pathogenic bacteria such as Salmonella entritidis, Salmonella gallinarum, Salmonella typhimurium, Clostridium perfringens, and Clostridium botulinum are highly resistant to glyphosate, but most beneficial bacteria such as Enterococcus faecalis, Enterococcus faecium, Bacillus badius, Bifidobacterium adolescentis, and Lactobacillus spp. were found to be moderately to highly susceptible. The relationship between the microbiome of the intestine and overall human health is still unclear, but current research indicates that disruption of the microbiome could cause diseases such as metabolic disorder, diabetes, depression, autism, cardiovascular disease, and autoimmune disease. 

Glyphosate and Chelation

Another study found that glyphosate accumulated in bones. Considering the strong chelating ability of glyphosate for calcium, accumulation in bones is not surprising. Other results showed that glyphosate is detectable in intestine, liver, muscle, spleen and kidney tissue. 5 The chelating ability of glyphosate also extends to toxic metals.10 The high incidence of kidney disease of unknown etiology (renal tubular nephropathy) has reached epidemic proportions among young male farm workers in sub-regions of the Pacific coasts of the Central American countries of El Salvador, Nicaragua, Costa Rica, India, and Sri Lanka.11 The researchers propose that glyphosate forms stable chelates with a variety of toxic metals that are then ingested in the food and water or, in the case of rice paddy workers, may be absorbed through the skin. These glyphosate-heavy metal chelates reach the kidney where the toxic metals damage the kidney. These authors also propose that these chelates accumulate in hard water and clay soils and persist for years, compared to much shorter periods of persistence for non-chelated glyphosate. Furthermore, these chelates may not be detected by common analytical chemistry methods that only detect free glyphosate, thus dramatically reducing estimates of glyphosate persistence in the environment when metals are high (for example, in clay soil or hard water). 

Testing for Glyphosate

Because glyphosate has been linked with many chronic health conditions, testing for glyphosate exposure and particularly the level of exposure is important. The lower limit of quantification (LLOQ) for The Great Plains Laboratory’s Glyphosate Test is 0.38 μg/g of creatinine. The Great Plains Laboratory is the only CLIA certified lab currently performing a test for glyphosate in urine. Our Glyphosate Test can be performed on the same urine sample as for some of our other comprehensive tests, including the Organic Acid Test (OAT) or GPL-TOX (Toxic Non-Metal Chemical Profile). See Figure 2 for an example of our Glyphosate Test report. 

As previously mentioned, glyphosate works by inhibiting the synthesis of tryptophan, phenylalanine, and tyrosine in plants. Humans need to obtain these amino acids from food sources. When food sources have scarce amounts of these amino acids due to glyphosate use, humans are at risk for deficiency too. Humans also require bacteria to maintain a healthy immune system. Research indicates that glyphosate decreases the amount of good bacteria in the gut such as bifidobacteria and lactobacilli and allows for the overgrowth of harmful bacteria such as campylobacter and C. difficile.12 Our lab has observed this in patients. We had a female patient who was suffering from depression who did a Glyphosate Test and an Organic Acids Test. Her glyphosate results were 2.99, which was over the 95th percentile and can be seen in Figure 3

 Figure 2

Figure 2

 Figure 4

Figure 4

 Figure 3

Figure 3

 Figure 5

Figure 5

Upon analyzing her OAT we noticed two things. The first was that her 4-cresol was extremely high. This increased 4-cresol can be seen in Figure 4. As stated earlier, glyphosate exposure decreases the good bacteria and allows C. difficile to invade. C. difficile produces a toxin called 4-cresol, which we measure in the OAT. Research has shown that 4-cresol inhibits dopamine beta-hydroxylase.13 Dopamine beta-hydroxylase converts dopamine to norepinephrine. In the OAT we measure both homovanillic acid (dopamine metabolite) and vanillylmandelic acid (norepinephrine metabolite). We have observed patients with a high 4-cresol value have elevated homovanillic acid, which indicates an inability to convert dopamine to norepinephrine. The results from our aforementioned patient were consistent with these other results and can be seen in Figure 5. The recommendations for this patient were to treat her glyphosate exposure and to treat her C. difficile infection. 

The results from these tests are indicative of why using the Organic Acids Test and Glyphosate Test together is so valuable and can help you provide more focused treatment for your patients. Treatment of glyphosate toxicity should be centered on determining the route of introduction and avoiding future exposure. Eating organic, non-GMO (genetically modified organism) foods and drinking reverse osmosis water are two of the best ways to avoid glyphosate. A recent study showed that people eating organic food had considerably lower concentrations of glyphosate in the urine.7 Drinking extra water may also be beneficial since glyphosate is water soluble, but that water should be filtered to remove pesticides or, ideally, be treated by reverse osmosis. More than 90% of corn and soy used are now of the GMO type. In addition, non-GMO wheat is commonly treated with glyphosate as a drying procedure. Glyphosate is somewhat volatile and a high percentage of rain samples also contained glyphosate.7 


High correlations exist between glyphosate usage and numerous chronic illnesses, including autism14. Other disease incidences with high correlations include hypertension, stroke, diabetes, obesity, lipoprotein metabolism disorder, Alzheimer’s, senile dementia, Parkinson’s, multiple sclerosis, inflammatory bowel disease, intestinal infections, end stage renal disease, acute kidney failure, cancers of the thyroid, liver, bladder, pancreas, kidney, and myeloid leukemia.14 Correlations are not causations, yet they raise concern over the use of a chemical to which all life on earth appears to be exposed. Testing for glyphosate along with specific markers in the Organic Acids Test can both help determine the level of exposure to glyphosate and guide you toward the most optimal treatment plans for your patients. 


1. Bradberry SM, Proudfoot AT, Vale JA. Glyphosate poisoning. Toxicol Rev. 2004;23(3):159-67. 

2. Mesnage R et al. Major pesticides are more toxic to human cells than their declared active principles. Biomed Res Int. 2014: 179691 

3. Samsel A, Seneff S. Glyphosate, pathways to modern diseases II: Celiac sprue and gluten intolerance. Interdiscip Toxicol. 2013;6:159-184. 

4. Samsel A, Seneff S. Glyphosate, pathways to modern diseases III: Manganese, neurological diseases, and associated pathologies. Surg Neurol Int. 2015; 6: 45. 

5. Krüger M, Schledorn P, Schrödl W, Hoppe HW, Lutz W, Shehata AA. Detection of Glyphosate Residues in Animals and Humans. J Environ Anal Toxicol. 2014. 4:2 0525.1000210 

6. Barbosa ER, Leiros da Costa MD, Bacheschi LA, Scaff M, Leite CC. Parkinsonism after glycine-derivative exposure. Mov Disord. 2001. 16: 565-568. 

7. Mesnage R, Defarge N, Spiroux de Vendômois J, Séralini GE. Potential toxic effects of glyphosate and its commercial formulations below regulatory limits. Food Chem Toxicol. 2015 Oct;84:133-53. 

8. Guyton KZ, Loomis D, Grosse Y et al. Carcinogenicity of tetrachlorvinphos, parathion, malathion, diazinon, and glyphosate. Lancet Oncol. 2015 May;16(5):490-1 

9. Shehata AA, Schrödl W, Aldin AA, Hafez HM, Krüger M. The effect of glyphosate on potential pathogens and beneficial members of poultry microbiota in vitro. Curr Microbiol. 2013 Apr;66(4):350-8. 

10. Jayasumana C, Gunatilake S, Siribaddana S. Simultaneous exposure to multiple heavy metals and glyphosate may contribute to Sri Lankan agricultural nephropathy. BMC Nephrology 2015;16:103. doi 10.1186/s12882-015-0109-2 

11. Jayasumana C, Gunatilake S, Senanayake P. Glyphosate, hard water and nephrotoxic metals: Are they the culprits behind the epidemic of chronic kidney disease of unknown etiology in Sri Lanka? Int. J. Environ. Res. Public Health 2014;11:2125-2147. 

12. Clair E et al. Effects of Roundup® and glyphosate on three food microorganisms: Geotrichum candidum, Lactococcus lactis subsp. cremoris and Lactobacillus delbrueckii subsp. bulgaricus. Curr Microbiol. 2012;64: 486-491. 

13. DeWolf WE Jr. Inactivation of dopamine beta-hydroxylase by p-cresol: isolation and characterization of covalently modified active site peptides. Biochemistry. 1988;27: 9093-9101. 

14. Swanson NL, Leu A, Abrahamson J, and Wallet B. Genetically engineered crops, glyphosate and the deterioration of health in the United States of America. Journal of Organic Systems. 2014; 9(2):6- 37. 

15. Environmental Protection Agency. Pesticides Industry Sales & Usage. 2006 and 2007 Market Estimates. Available at estimates2007.pdf. Accessed July 15, 2015. 

16. Shehata AA et al. The effect of glyphosate on potential pathogens and beneficial members of poultry microbiota in vitro. Curr. Microbiol. 2013;66: 350-358. 

17. Larsen K et al. Effects of sublethal exposure to a glyphosate-based herbicide formulation on metabolic activities of different xenobiotic-metabolizing enzymes in rats. Int J Toxicol. 2014;33: 307-318. 

William Shaw, PhD, is board certified in the fields of clinical chemistry and toxicology by the American Board of Clinical Chemistry. Before he founded the Great Plains Laboratory Inc., Dr. Shaw worked for the Centers for Disease Control and Prevention (CDC), Children’s Mercy Hospital, University of Missouri at Kansas City School of Medicine, and Smith Kline Laboratories. He is the author of Biological Treatments for Autism and PDD, originally published in 1998, and Autism: Beyond the Basics, published in 2009. He is also a frequent speaker at conferences worldwide. 

He is the stepfather of a child with autism and has helped thousands of patients and medical practitioners to successfully improve the lives of people with autism, AD(H)D, Alzheimer’s disease, arthritis, bipolar disorder, chronic fatigue, depression, fibromyalgia, immune deficiencies, multiple sclerosis, OCD, Parkinson’s disease, seizure disorders, tic disorders, Tourette syndrome, and other serious conditions. 

Matthew Pratt-Hyatt, PhD, received his PhD in cellular and molecular biology from the University of Michigan. He has trained under Dr. Paul Hollenberg, a prominent researcher on drug metabolism, and Dr. Curtis Klaassen, one of the world’s leading toxicologists. He has over a dozen publications in well-known research journals such as the PNAS and Cell Metabolism. He is currently associate laboratory director at the Great Plains Laboratory Inc. in Lenexa, Kansas, focused on diagnosis and treatment of mitochondrial disorders, neurological diseases, chronic immune diseases, and more. He specializes in developing tools that examine factors at the interface between genetics and toxicology. His work is bringing new insight into how genes and toxicants interact and how that may lead to mental health disorders, chronic health issues, and metabolism disorders. 

Radio Show Interview about Glyphosate - Dr. William Shaw

This is a radio show interview with Dr. William Shaw on local New York station WBAI 99.5 from April 15, 2016. Take Charge of Your Health hosts Corinne Funari, RPA, CCN and Linda Segal interviewed Dr. Shaw about the dangers of glyphosate, the world's most widely used herbicide being sprayed on our crops.  To listen to the show, click here.  Dr. Shaw's interview starts at 13:00.

Toxic Crumb Rubber: Nothing to Play Around With

Matt Pratt-Hyatt, Ph.D.


As a parent of two young children I understand that parents have a long list of things to worry about. We parents worry if our children are eating right, getting enough sleep, or if they're making friends. Unfortunately, we now also have to worry about the toxic environment to which our children may be exposed, be it the toys they are playing with or the cups they use for drinking. The latest data shows that the playgrounds and artificial turf fields they play on may be quite toxic and hazardous to their health.

In the last two decades, many playgrounds, soccer fields, and football fields have been replacing their natural surfaces with a synthetic surface of rubber granules made up of ground up tires. Despite the popularity of these types of surfaces many different activist groups have expressed concern that these synthetic materials may be a toxic burden on our children.

In 2006 a commentary was written in Environmental Health Perspectives detailing how little we knew about the material we are having our children play on (Anderson et al, 2006). In the years since, there have been some insightful studies performed that give clues into how harmful prolonged exposure to these playing fields may be. In 2007, a study from the nonprofit organization Environment and Human Health, Inc. and the Department of Analytical Chemistry at the Connecticut Agricultural Experimental Station produced one of the first reports about chemicals found leaching from artificial surfaces made from rubber tires. This report indicated that benzothiazole, butylated hydroxyanisole, n-hexadecane, 4-(t-oxtyl) phenol, and zinc were found leaching from the tires. These chemicals are known carcinogens and neurotoxicants (Brown et al., 2007).

A second report in 2008 in the Journal of Exposure Science and Environmental Epidemiology provided some additional data on the chemicals that could affect children. The report indicated that the rubber granules have a much higher amount of polycyclic aromatic hydrocarbons (PAHs) than soil. Zinc and chromium were also found to be much higher in the artificial surfaces than in soil. The report also stated that although lead was not found to be much higher than in soil the bioaccessibility was much higher (Zhang et al, 2008). PAHs are known neurotoxic chemicals which have been found in air pollution from fossil fuel combustion. A recent study published in PLOS One from the University of Columbia discovered a link between PAH exposure and the development of attention deficit and hyperactivity problems (Perera et al., 2014).

In the last several years many alternatives to crumb rubber have emerged. One drawback to these alternatives is that they will add cost to the play area project. However, these costs do not calculate the damage these surfaces may be inflicting on our children. In light of the new data, any new playground or school field should reconsider the use of crumb rubber.