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Many of us grew up having silver colored dental fillings (called dental amalgam) in our teeth. Dental amalgam has been used for over 150 years for the treatment of dental cavities (caries) because it is durable, easy to use, and affordable. But it is composed of about 50% elemental mercury (Hg) and so it may release a certain amount of mercury both during the time the cavity is filled and afterward with normal wear. Mercury can cause adverse health effects, such as effects on the central nervous system, kidneys, and immune system. Human mercury exposure also occurs through the consumption of mercury (MeHg) contaminated seafood.

Recently many dentists switched to the use of the composite resins, which are mercury-free alternative materials. However, these can release can release small quantities of bisphenol A (BPA) when applied and as they degrade in the mouth. BPA is an endocrine disruptor, has been found to cause various adverse health effects, including reproductive effects, and can be measured in urine. Which raised the question, do persons with composite resin fillings have elevated BPA in their bodies?

This study examined 14,703 subjects who were divided into three groups based on the number of dental surface restorations (DSR): 0, 1–8, or greater than 8. Dental surface restorations applies to fillings, and not crowns. Note that a tooth's surface can have 5 surfaces (in molars and pre-molars), so 8 filled surfaces can be fewer than 8 teeth with fillings. (It's not the number of fillings, but the surface area they occupy - so the Science Daily article title is misleading.)

They found that the more dental surface restorations a person has, the higher the levels of mercury in the blood. But they found no association between dental surface restorations and urinary BPA. These results are reassuring for those with fillings made of composite resins, but not for people with fillings of dental amalgam. Note: DSR are Dental Surface Restorations, THg is blood total mercury, IHG is inorganic mercury, and MeHg is methyl mercury (typically from seafood). From Science Daily:

Have more than eight dental fillings? It could increase the mercury levels in your blood

Dental surface restorations composed of dental amalgam, a mixture of mercury, silver, tin and other metals, significantly contribute to prolonged mercury levels in the body, according to new research from the University of Georgia's department of environmental health science in the College of Public Health.This research, which analyzed data from nearly 15,000 individuals, is the first to demonstrate a relationship between dental fillings and mercury exposure in a nationally representative population.  ...continue reading "Dental Fillings and Mercury Levels"

Ten chemicals suspected or known to harm human health are present in more than 90% of U.S. household dust samples, according to a new study. The research adds to a growing body of evidence showing the dangers posed by exposure to chemicals we are exposed to on a daily basis. The chemicals come from a variety of household goods, including toys, cosmetics, personal care products, furniture, electronics, nonstick cookware, food packaging, floor coverings, some clothing (e.g., stain resistant), building materials, and cleaning products. How do the chemicals get into the dust? The chemicals can leach, migrate, abrade, or off-gas from the products, which winds up in the dust and  results in human exposure. (That's right:  vacuum a lot and wash your hands a lot, and try to avoid or cut  back use of products with these chemicals,)

What was found in the dust? The main chemicals were: phthalates — a group of chemicals that includes DEP, DEHP, DNBP and DIBP (these were present in the highest concentrations),  highly fluorinated chemicals (HFCs), flame retardants (both old and newer replacement ones), synthetic fragrances, and phenols. These chemicals are known to have various adverse health effects, including endocrine disruption, cancer, neurological, immune, and developmental effects. (See posts on endocrine disruptors and flame retardants) Studies typically study one chemical at a time, but household dust contains MIXTURES of these chemicals with effects unknown. How does it get into us? Inhalation, ingestion, and through skin contact. And while the levels we are exposed to may be low, research is showing that even low level exposure can have adverse health effects. From Medical Xpress:

Potentially harmful chemicals widespread in household dust

Household dust exposes people to a wide range of toxic chemicals from everyday products, according to a study led by researchers at Milken Institute School of Public Health at the George Washington University. The multi-institutional team conducted a first-of-a-kind meta-analysis, compiling data from dust samples collected throughout the United States to identify the top ten toxic chemicals commonly found in dust. They found that DEHP, a chemical belonging to a hazardous class called phthalates, was number one on that list. In addition, the researchers found that phthalates overall were found at the highest levels in dust followed by phenols and flame retardant chemicals....."The findings suggest that people, and especially children, are exposed on a daily basis to multiple chemicals in dust that are linked to serious health problems." ...continue reading "What’s In Your Household Dust?"

Over the years I have read about some oils, especially lavender and tea tree oils,  as having hormone altering (endocrine disrupting) effects when used over prolonged periods of time or when someone is "chronically exposed". Especially worrisome was the possible estrogenic effects of lavender oils in shampoos, lotions, and soaps on developing children - especially boys (prolonged use leading to the development of breasts in some boys!). I just read a recently published journal study (with very interesting comments at the end), and an article in WebMD about this same topic. The condition of early breast development is called prepubertal gynecomastia in boys and thelarche in girls.

As you can imagine, the industry (Australian Tea Tree Industry Association and Research Institute for Fragrance Materials Inc) calls such research  "poor science". Of course industry sponsored "research" never ever finds any problems (because any "problems" would impact the big $$ from the sale of those products). In fact, I would be skeptical of any industry sponsored research in this area - it is not truly independent, unbiased research if they "have to" and "want to" find no problems. So when you do read industry research, also read the rebuttals by independent scientists and doctors.

Bottom line: No matter the age, avoid prolonged use of lavender and tea tree oil in personal care products, including "aromatherapy" -  especially important for children and pregnant women. The good news is that the development of breasts in young children is reversible when use of the product is stopped. But better to avoid such products (including Agua de Violetas) on children in the first place. Instead use unscented personal care products.

From WebMD:  Are Tea Tree and Lavender Oils Safe for Kids?

Tea tree and lavender essential oils are popular ingredients in personal care and household products, including many aimed at children. But can the ingredients, often promoted as “natural” alternatives, trigger abnormal breast growth in boys and girls? A few small studies suggest that frequently using lotions, shampoos, styling gels, and even a certain cologne containing lavender and tea tree oils may cause breast growth in boys, also known as gynecomastia, along with breast growth in girls as young as 4 or 5

Other studies have not reached the same conclusions, and the cases appear to be rare. In addition, scientific research into most natural products is scant. The FDA doesn’t oversee essential oils unless they are intended for use in a drug, making it challenging to know how safe and effective these products are....Lavender and tea tree oils are among the most commonly used essential oils used. Although research is inconclusive, lavender is often used for aromatherapy and calming lotions, while tea tree oil is promoted for acne, nail fungus, and other skin conditions

...continue reading "Avoid Lavender and Tea Tree Oils In Personal Care Products?"

Studies are accumulating evidence that the hormone disrupting effects of compounds BPA (bisphenol A) and BPS (the common substitute for BPA) have numerous negative health effects in humans, including reproductive disorders. But now a second BPA substitute - BPSIP - is also being found in humans, and may be even more persistent than BPA and BPS. This is because they're all chemically similar, and all three are endocrine disruptors. This article points out that they have slightly different effects, and when we are exposed to more than one of them (which we are), then the health effects will be even more worrisome.

Unfortunately these plasticizers are in products all around us, and so detected within almost all of us. They're in food packaging containers (and therefore in food), water bottles, can linings, toys, personal care products, thermal paper products such as cash receipts, etc. Canned foods are considered one of the most significant routes of human exposure to bisphenol A (BPA).

Other endocrine disruptors include phthalates - so read personal care product labels to avoid these. Another way to lower exposure to endocrine disruptors is to buy and store food not in plastic containers, but in glass containers or stainless steel. Don't microwave food in any sort of plastic containers. Avoid products with fragrances in them, including air fresheners. Avoid flexible vinyl (e.g. shower curtains). (For all posts on endocrine disruptors, and an article from National Institutes of Health.) From PLOS Biology:

Wreaking Reproductive Havoc One Chemical at a Time

Bisphenol A (BPA), unlike DES, remained obscure until the 1950s, when chemists tapped it to make polycarbonate plastics and epoxy resins. BPA now tops the list of high-volume chemicals, and is found in numerous consumer products, including water bottles, food packaging containers and can linings, and thermal paper products like cash receipts and boarding passes (Fig 1). And because it can leach out of products, it’s been detected in the urine of nearly every person tested. It’s also been found in breast milk, follicular and amniotic fluid, cord blood, placental tissue, fetal livers, and the blood of pregnant women.

Hundreds of studies have associated the BPA levels found in most of us with reproductive disorders, cancers, obesity, and other adverse effects in both animals and humans. Although chemical manufacturers with a stake in the $16 billion BPA market continue to question this evidence, they’ve responded to safety concerns by offering BPA-free alternatives. But as a recent study in PLOS Genetics [1] shows, the new versions seem an awful lot like the original. When one chemical comes under scrutiny, manufacturers often substitute compounds with similar structures to save time and money. But similar structures often cause similar problems. And that’s exactly what the PLOS Genetics authors found.

Thinking BPA’s replacement, bisphenol S (BPS), might target the same pathways, Patrick Allard and his colleagues at the University of California at Los Angeles compared the effects of both substances....But, surprisingly, the authors say, the two bisphenols gummed up the works through somewhat different molecular steps. That means simultaneous exposure to BPA and BPS could potentially cause even more reproductive harm. Future studies will need to confirm this possibility, but it’s an unsettling prospect given the ubiquity of BPA and increasing use of BPS, which has already been found in food, shampoo, face cream and other personal care products, soil, and thermal paper products.

And now there’s another “safer” alternative to worry about, researchers reported in Environmental Health Perspectives [2]. Suspecting that cashiers would face higher exposures on the job, the authors screened their urine, blood, and receipts (as well as people who didn’t handle receipts) for BPA, BPS, and another analog called BPSIP. Cashiers’ BPA levels after work were highly variable, likely resulting from its widespread use, but levels of BPS and BPSIP were higher in most cases. Both BPS and BPSIP were also detected in people who weren’t cashiers....The authors were also surprised to see BPSIP in cashiers’ blood more often than the other compounds, suggesting it may be more persistent and our exposure more widespread than previously assumed. BPSIP’s health effects are unknown.

Much more is known about BPA’s estrogenic powers. Earlier this year Pat Hunt, who was among the first to report BPA’s ability to scramble mouse eggs [3], reported similar problems in mouse sperm in PLOS Genetics [4]. Low sperm counts, undescended testicles, malformed penises, and other reproductive anomalies have risen in recent decades, suggesting environmental estrogens may play a role. Hunt’s team investigated this possibility by exposing newborn male mice to BPA or a stronger synthetic estrogen, ethinyl estradiol, just when sperm differentiation begins. BPA exposure disrupts meiosis in males as it does in female mice, the authors discovered, but in different ways....

Health researchers are especially concerned about environmental contaminants that reach the womb during critical windows when even the slightest disturbance can rewire developmental programs to produce profound, irreversible changes that can take years to appear. These changes can cause a plethora of chronic health problems, including diabetes, cardiovascular disorders, birth defects, and cancer.

Two recent articles about BPA (bisphenol A), BPS (bisphenol B), and the "BPA-free" label  - one a study, and one a review article. The "BPA-free" label unfortunately means the product contains a product similar to BPA (typically BPS) and with the same problems as BPA. Both articles discuss the accumulating health reasons to try to avoid these endocrine disruptors. Which is really , really tough to do given that plastics are all around us and used by us every day.

From Science Daily: Prenatal BPA exposure linked to anxiety and depression in boys

Boys exposed prenatally to a common chemical used in plastics may be morelikely to develop symptoms of anxiety and depression at age 10-12. The new study by researchers at the Columbia Center for Children's Environmental Health (CCCEH) within the Mailman School of Public Health examined early life exposure to the chemical Bisphenol A (BPA). Results are published in the journal Environmental Research.

BPA is a component of some plastics and is found in food containers, plastic water bottles, dental sealants, and thermal receipt paper. In the body, BPA is a synthetic estrogen, one of the class of chemicals known as "endocrine disruptors." The Columbia researchers, led by Frederica Perera, PhD, DrPH, director of CCCEH, previously reported that prenatal exposure to BPA was associated with emotionally reactive and aggressive behavior, and more symptoms of anxiety and depression in boys at age 7-9.

Perera and her co-investigators followed 241 nonsmoking pregnant women and their children, a subset of CCCEH's longstanding urban birth cohort study in New York City, from pregnancy through childhood....Researchers controlled for factors that have been previously associated with BPA exposure levels, including socioeconomic factors. After separating the data by sex, they found that boys with the highest levels of prenatal exposure to BPA had more symptoms of depression and anxiety than boys with lower levels of prenatal exposure to BPA; no such associations were found in girls.

From Endocrine News: Warning Signs: How Safe Is “BPA Free?”

While stickers are showing up declaring certain products “BPA Free,” that doesn’t mean they’re necessarily safe. Could bisphenol S be even worse than the compound it is supposed to be replacing? 

Human exposure to BPA is as ubiquitous as the stickers showing up now that proclaim products BPA free. The chemical used to make plastic has been linked to all kinds of reproductive issues, and even thought to play a role in the development of obesity and cardiovascular events, so industry is taking some steps to correct the problem (after much wailing and gnashing of teeth on their part). These stickers read “BPA FREE” and “NON-TOXIC PLASTIC” in bold letters and usually feature leaves and a green motif, the implication being that these products are safe and healthy. 

But “BPA free” does not mean “EDC free” [endocrine disruptor free] and many products now contain bisphenol S as a substitute for BPA. BPS is a similar chemical and has been found in everything from canned soft drinks to receipt paper to baby bottles. (The FDA banned BPA in baby bottles.) It’s been found in indoor dust samples and is beginning to show up in human urine, and it has been reported to be less biodegradable than BPA. Animal studies have implicated BPS in impaired offspring development. And the production of BPS is increasing annually.

“Recent studies testing BPS and comparing it to BPA show that BPS is as bad, if not worse, than BPA as an EDC,” says Andrea Gore, PhD, professor and Vacek Chair of Pharmacology at the University of Texas in Austin, and editor-in-chief of Endocrinology. “’BPA free’ can give consumers a false sense of security about the product.”

According to Kimberly H. Cox, a postdoctoral fellow studying reproductive endocrinology at Massachusetts General Hospital in Boston, the effects of BPA and BPS are subtler than say, PCBs or pesticides, where exposures came at high levels, with devastating effects. The effects of BPA and BPS depend on the timing, length, and dose of exposure, and numerous studies have shown that there are effects on the reproductive system, for example, at doses of BPA much lower than what has been determined as a “safe” exposure by the EPA. And now there also seem to be effects of BPS on the development of the reproductive system, as well as the brain regions that control reproduction.

“When endocrinologists talk about BPA, they frequently describe it as estrogenic – and do not point out the other endocrine systems that are being altered, such as thyroid hormone,” Wayne says. “Our paper emphasizes that BPA and BPS are activating both estrogenic and thyroid hormone pathways. This suggests that EDCs are having much broader effects on health and disease than just mimicking estrogens (which is bad enough).”

Take note: what is happening to dogs is also happening to men. Specifically, for many decades - year by year - there has been a decrease in male dog fertility. And yes, this is also happening with human male fertility - a decline in male semen quality (including sperm), along with an increase in the incidence of testicular cancer, the birth defect hypospadias, and undescended testes. This cluster of problems is called testicular dysgenesis syndrome (TGS), and it has an negative impact on male fertility.

Dr Richard Lea, who led the research said: "This is the first time that such a decline in male fertility has been reported in the dog and we believe this is due to environmental contaminants..." and "While further research is needed to conclusively demonstrate a link, the dog may indeed be a sentinel for humans -- it shares the same environment, exhibits the same range of diseases, many with the same frequency, and responds in a similar way to therapies."

What chemicals were detected that affect male fertilty? Why, the same chemicals that appear again and again in studies and are linked to a number of health problems: endocrine disruptors. Yes, they are all around us - in our food, our homes, our everyday products, our environment. From Science Daily:

Study demonstrates rapid decline in male dog fertility, with potential link to environmental contaminants

A study led by researchers at The University of Nottingham has discovered that the fertility of dogs may have suffered a sharp decline over the past three decades. The research, published in the academic journal Scientific Reports, found that sperm quality in a population of stud dogs studied over  a 26-year period had fallen significantly.The work has highlighted a potential link to environmental contaminants, after they were able to demonstrate that chemicals found in the sperm and testes of adult dogs -- and in some commercially available pet foods -- had a detrimental effect on sperm function at the concentrations detected.

 The study centered on samples taken from stud dogs at an assistance dogs breeding center over the course of 26 years. Professor Gary England.... said: "The strength of the study is that all samples were processed and analysed by the same laboratory using the same protocols during that time and consequently the data generated is robust." The work centred on five specific breeds of dogs -- Labrador retriever, golden retriever, curly coat retriever, border collie and German shepherd -- with between 42 and 97 dogs studied every year. Semen was collected from the dogs and analysed to assess the percentage of sperm that showed a normal forward progressive pattern of motility and that appeared normal under a microscope (morphology).

Over the 26 years of the study, they found a striking decrease in the percentage of normal motile sperm. Between 1988 and 1998, sperm motility declined by 2.5 per cent per year and following a short period when stud dogs of compromised fertility were retired from the study, sperm motility from 2002 to 2014 continued to decline at a rate of 1.2% per year. In addition, the team discovered that the male pups generated from the stud dogs with declining semen quality, had an increased incidence of cryptorchidism, a condition in which the testes of pups fail to correctly descend into the scrotum.

Sperm collected from the same breeding population of dogs, and testes recovered from dogs undergoing routine castration, were found to contain environmental contaminants at concentrations able to disrupt sperm motility and viability when testedThe same chemicals that disrupted sperm quality, were also discovered in a range of commercially available dog foods -- including brands specifically marketed for puppies. Dr Lea added: "We looked at other factors which may also play a part, for example, some genetic conditions do have an impact on fertility. However, we discounted that because 26 years is simply too rapid a decline to be associated with a genetic problem."

Over the past 70 years, studies have suggested a significant decline in human semen quality and a cluster of issues called 'testicular dysgenesis syndrome' that impact on male fertility which also include increased incidence of testicular cancer, the birth defect hypospadias and undescended testes.

However, declining human semen quality remains a controversial issue -- many have criticised the variability of the data of the studies on the basis of changes in laboratory methods, training of laboratory personnel and improved quality control over the years. Dr Lea added: "The Nottingham study presents a unique set of reliable data from a controlled population which is free from these factors. This raises the tantalising prospect that the decline in canine semen quality has an environmental cause and begs the question whether a similar effect could also be observed in human male fertility."

Excerpts from the original study in Scientific Reports: Environmental chemicals impact dog semen quality in vitro and may be associated with a temporal decline in sperm motility and increased cryptorchidism

A significant decline in human semen quality over the last 70 years has been widely reported1,2. The first meta-analysis reporting this phenomenon included 61 studies selected over a 50 year period (1938–1991)1 and such a trend was confirmed by re-analysis with an additional 47 studies included2.....Nevertheless, reports of declining sperm counts linked with epidemiological data on increased incidences of testicular cancer and genital tract abnormalities, is indicative of an adverse environmental effect on male reproduction6,7,8. Since these reproductive problems, termed by some as “testicular dysgenesis syndrome” (TDS), cluster in geographical areas9 they are thought to have a common aetiology and have been associated with endocrine perturbations in early life10. Exposure of developing males to environmental chemicals, particularly those with endocrine disrupting activity, is thought to be the initiator11. Although periods of development particularly sensitive to exposure encompass both pre-natal and pre-pubertal periods, environmental chemicals also perturb adult testis function e.g. gene expression and meiosis12

As ‘man’s best friend’ and closest animal companion, the dog shares the same environment, exhibits the same range of diseases, many with the same frequency, and responds in a similar way to therapeutic treatments. There is evidence that over the last 40 years, the incidence rate of canine testicular cancer has increased in parallel with changes seen in humans17,18. In addition, histological signs which characterise human TDS have recently been described in the dog19. These include seminiferous tubule abnormalities and testicular germ cell neoplasia in situ (GCNIS) cells which are known precursors of seminomas in the human20. Since human TDS includes a reduction in sperm count21 and an increased incidence of cryptorchidism, we hypothesised that the dog may exhibit similar manifestations of TDS and that this may be associated with exposure to endocrine disrupting chemicals.  

The dog is probably man’s closest companion and by sharing the same habitat, is likely to be exposed to similar environmental conditions including environmental chemicals. This was especially true in the current study since the dogs lived in homes with their handlers. Twelve chemicals detected in adult dog testes (DEHP, 7 PCB congeners, 4 PBDE congeners) were also detected in the 15 commercially available dog foods analysed

 A new report authored by dozens of scientists, health practitioners and children's health advocates is highlighting the (growing annually) evidence that many common and widely available chemicals endanger neurological development in fetuses and children of all ages. The chemicals contribute to such health problems as ADHD, autism spectrum disorders, lowered IQ, behavior disorders, and many other problems. Many of the chemicals have hormonal effects (endocrine disruptors) and interfere with normal hormonal activity. The chemicals of highest concern are all around us and are found in most pregnant women, their fetuses, and in growing children. In fact, in all of us.

Especially worrisome chemicals are:  leadmercury; organophosphate pesticides (used in agriculture and home gardens), phthalates (in medicines, plastics, and personal care products), flame retardants known as polybrominated diphenyl ethers (found in upholstered furniture, car seats), air pollutants produced by the combustion of wood and fossil fuels), and polychlorinated biphenyls (once used as coolants and lubricants in electrical equipment, but still pervasive). It is important to note that out of the thousands of chemicals that people are exposed to, that the great majority of chemicals are untested for neurodevelopmental effects.

Especially alarming is that the U.S. Centers for Disease Control found that 90% of pregnant women in the United States have detectable levels of 62 chemicals in their bodies, out of 163 chemicals for which the women were screened. This shows that we are exposed to mixtures of chemicals - not just to one chemical at a time.  Unfortunately the substitutes for problematic chemicals are NO better than the originals, because they tend to be similar chemically. For example, the substitutes for BPA are just as bad, if not worse, than BPA (bisphenol A). And remember, we are exposed to mixtures of chemicals - not just to one chemical at a time.

The report criticizes current regulatory lapses that allow chemicals to be introduced into people's lives with little or no review of their effects on fetal and child health. "For most chemicals, we have no idea what they're doing to children's neurodevelopment," Professor Schantz (one of the signers of the report) said. "They just haven't been studied." So why aren't policymakers doing something? Why is industry dictating what we're exposed to? Why are chemicals innocent until proven guilty, and even then they're allowed to be used? Who is looking out for the ordinary person, and especially developing children?

From the journal Environmental Health Perspectives: Project TENDR: Targeting Environmental Neuro-Developmental Risks. The TENDR Consensus Statement

Children in America today are at an unacceptably high risk of developing neurodevelopmental disorders that affect the brain and nervous system including autism, attention deficit hyperactivity disorder, intellectual disabilities, and other learning and behavioral disabilities. These are complex disorders with multiple causes—genetic, social, and environmental. The contribution of toxic chemicals to these disorders can be prevented. 

Leading scientific and medical experts, along with children’s health advocates, came together in 2015 under the auspices of Project TENDR: Targeting Environmental Neuro-Developmental Risks to issue a call to action to reduce widespread exposures to chemicals that interfere with fetal and children’s brain development. Based on the available scientific evidence, the TENDR authors have identified prime examples of toxic chemicals and pollutants that increase children’s risks for neurodevelopmental disorders. These include chemicals that are used extensively in consumer products and that have become widespread in the environment. Some are chemicals to which children and pregnant women are regularly exposed, and they are detected in the bodies of virtually all Americans in national surveys conducted by the U.S. Centers for Disease Control and Prevention. The vast majority of chemicals in industrial and consumer products undergo almost no testing for developmental neurotoxicity or other health effects.

Based on these findings, we assert that the current system in the United States for evaluating scientific evidence and making health-based decisions about environmental chemicals is fundamentally broken. To help reduce the unacceptably high prevalence of neurodevelopmental disorders in our children, we must eliminate or significantly reduce exposures to chemicals that contribute to these conditions. We must adopt a new framework for assessing chemicals that have the potential to disrupt brain development and prevent the use of those that may pose a risk. This consensus statement lays the foundation for developing recommendations to monitor, assess, and reduce exposures to neurotoxic chemicals. 

The TENDR Consensus Statement is a call to action to reduce exposures to toxic chemicals that can contribute to the prevalence of neurodevelopmental disabilities in America’s children. The TENDR authors agree that widespread exposures to toxic chemicals in our air, water, food, soil, and consumer products can increase the risks for cognitive, behavioral, or social impairment, as well as specific neurodevelopmental disorders such as autism and attention deficit hyperactivity disorder (ADHD) (Di Renzo et al. 2015; Gore et al. 2015; Lanphear 2015; Council on Environmental Health 2011). This preventable threat results from a failure of our industrial and consumer markets and regulatory systems to protect the developing brain from toxic chemicals. To lower children’s risks for developing neurodevelopmental disorders, policies and actions are urgently needed to eliminate or significantly reduce exposures to these chemicals.

We are witnessing an alarming increase in learning and behavioral problems in children. Parents report that 1 in 6 children in the United States, 17% more than a decade ago, have a developmental disability, including learning disabilities, ADHD, autism, and other developmental delays (Boyle et al. 2011). As of 2012, 1 in 10 (> 5.9 million) children in the United States are estimated to have ADHD (Bloom et al. 2013). As of 2014, 1 in 68 children in the United States has an autism spectrum disorder (based on 2010 reporting data) (CDC 2014).

Many toxic chemicals can interfere with healthy brain development, some at extremely low levels of exposure. Research in the neurosciences has identified “critical windows of vulnerability” during embryonic and fetal development, infancy, early childhood and adolescence (Lanphear 2015; Lyall et al. 2014; Rice and Barone 2000). During these windows of development, toxic chemical exposures may cause lasting harm to the brain that interferes with a child’s ability to reach his or her full potential.

The developing fetus is continuously exposed to a mixture of environmental chemicals (Mitro et al. 2015). A 2011 analysis of the U.S. Centers for Disease Control and Prevention’s (CDC) biomonitoring data found that 90% of pregnant women in the United States have detectable levels of 62 chemicals in their bodies, out of 163 chemicals for which the women were screened (Woodruff et al. 2011). Among the chemicals found in the vast majority of pregnant women are PBDEs, polycyclic aromatic hydrocarbons (PAHS), phthalates, perfluorinated compounds, polychlorinated biphenyls (PCBs), perchlorate, lead and mercury (Woodruff et al. 2011). Many of these chemicals can cross the placenta during pregnancy and are routinely detected in cord blood or other fetal tissues.

The following list provides prime examples of toxic chemicals that can contribute to learning, behavioral, or intellectual impairment, as well as specific neurodevelopmental disorders such as ADHD or autism spectrum disorder: Organophosphate (OP) pesticides, PBDE flame retardants, combustion-related air pollutants, which generally include PAHs, nitrogen dioxide and particulate matter, and other air pollutants for which nitrogen dioxide and particulate matter are markers, lead, mercuryPCBs .

The United States has restricted some of the production, use and environmental releases of these particular chemicals, but those measures have tended to be too little and too late. We face a crisis from both legacy and ongoing exposures to toxic chemicals.....The examples of developmental neurotoxic chemicals that we list here likely represent the tip of the iceberg....Only a minority of chemicals has been evaluated for neurotoxic effects in adults. Even fewer have been evaluated for potential effects on brain development in children (Grandjean and Landrigan 2006, 2014). Further, toxicological studies and regulatory evaluation seldom address combined effects of chemical mixtures, despite evidence that all people are exposed to dozens of chemicals at any given time.

Some chemicals, like those that disrupt the endocrine system, present a concern because they interfere with the activity of endogenous hormones that are essential for healthy brain development. Endocrine-disrupting chemicals (EDCs) include many pesticides, flame retardants, fuels, and plasticizers. One class of EDCs that is ubiquitous in consumer products are the phthalates. These are an emerging concern for interference with brain development and therefore demand attention.

Under our current system, when a toxic chemical or category of chemicals is finally removed from the market, chemical manufacturers often substitute similar chemicals that may pose similar concerns or be virtually untested for toxicity. This practice can result in “regrettable substitution” whereby the cycle of exposures and adverse effects starts all over again. The following list provides examples of this cycle: When the federal government banned some uses of OP pesticides, manufacturers responded by expanding the use of neonicotinoid and pyrethroid pesticides. Evidence is emerging that these widely used classes of pesticides pose a threat to the developing brain (Kara et al. 2015; Richardson et al. 2015; Shelton et al. 2014). 

When the U.S. Government reached a voluntary agreement with flame retardant manufacturers to stop making PBDEs, the manufacturers substituted other halogenated and organophosphate flame retardant chemicals. Many of these replacement flame retardants are similar in structure to other neurotoxic chemicals but have not undergone adequate assessment of their effects on developing brains. When the federal government banned some phthalates in children’s products, the chemical industry responded by replacing the banned chemicals with structurally similar new phthalates. These replacements are now under investigation for disrupting the endocrine system.

A recent study found that school age children with higher levels of BPA in their bodies were more likely to have an ADHD (Attention Deficit Hyperactivity Disorder)  diagnosis. BPA or Bisphenol A is everywhere (in plastics, linings of cans, etc), found in varying levels in almost everyone, but at least it is eliminated fairly rapidly from the body. So trying to avoid BPA (e.g., buying and storing food in glass containers rather than cans or plastic containers) can quickly lower levels in the body. From Environmental Health News:

Hyperactivity in children linked to plastic additive, BPA

Children in the U.S. with higher levels of BPA in their bodies were more likely to have Attention-Deficit/Hyperactivity Disorder (ADHD), according to a study. The study of 460 children across the U.S. aged 8 to 15 years old found that 11 percent of those with BPA levels higher than the median level had ADHD. In contrast, 3 percent of those children with BPA levels below the median had ADHD. The research, published online last week in the Environment Research journal, adds to evidence that children’s BPA exposure may alter brain development and lead to behavior problems such as reduced attention and hyperactivity. 

The association was stronger for boys than girls, which reflects broader ADHD rates. Nationally about 10 percent of children between 5 and 17 have had an ADHD diagnoses, with boys having a much higher rate at 14 percent. By comparison about 6 percent of girls have the disorder, according to the U.S. Centers for Disease Control and Prevention.....BPA mimics estrogen hormones.The sexes use hormones differently to influence brain function.

BPA—used to make plastic hard and shatterproof and to extend the shelf life of canned food—can leach out of can linings and into the food. Studies show that just about everyone has traces of the chemical in their body—for instance, 97 percent of the children in this study had BPA in their urine. The additive has been linked to multiple health impacts in exposed babies and children—including obesity, asthma, low birth weights and genital defects.

A 2014 study on prenatal exposure to BPA found higher levels meant more behavior problems for school-age boys. Evans, lead author of that study, said prenatal exposure to chemicals is a “window of high susceptibility,” but so are the childhood years. The brain keeps developing into the 20s. Research specifically looking at ADHD and BPA exposure has been mixed, with some finding a link and some not. Most of the previous studies, however, have been on children younger than 8 years old, and ADHD and its symptoms are often realized later than that.

Animal studies show that BPA may alter the body’s dopamine—a chemical messenger that helps people think and stay alert and focused. “Dopamine systems are modulated by estrogen and BPA is a synthetic estrogen,” Froehlich said. There are also suggestions that BPA can interact with thyroid hormones—“critical in normal brain development,” Evans said.

A new report released by the non-profit environmental research organization Environmental Working Group (EWG) has found that up to 420 chemicals known or likely to cause cancer have been measured in people (detected in urine, blood, hair, etc). Exposure to these carcinogens is not just from on-the-job contact with industrial chemicals, but from ordinary everyday exposure such as consumer products, food, water, air, and pesticides used in the home and lawns.

EWG compiled this inventory of known or likely carcinogens that have been measured in people by reviewing scientific literature and publicly available biomonitoring studies. Biomonitoring is the laboratory analysis of blood, urine, serum, saliva, and other body fluids to identify the amount and number of certain chemicals (such as pesticides, fire retardants, BPA, etc) present in the human body.  Thus it measures the extent to which chemical pollution is absorbed by our bodies. The CDC has a National Biomoniitoring Program. From Environmental Working Group (EWG):

Hundreds Of Cancer-Causing Chemicals Pollute Americans’ Bodies

Hundreds of cancer-causing chemicals are building up in the bodies of Americans, according to the first comprehensive inventory of the carcinogens that have been measured in people. EWG released the inventory today. EWG spent almost a year reviewing more than 1,000 biomonitoring studies and other research by leading government agencies and independent scientists in the U.S. and around the world. The nonprofit research group found that up to 420 chemicals known or likely to cause cancer have been detected in blood, urine, hair and other human samples.

Studies of the causes of cancer often focus on tobacco, alcohol and over-exposure to the sun. But the World Health Organization and many other scientists believe nearly 1 in 5 cancers are caused by chemicals and other environmental exposures––not only in the workplaces, but in consumer products, food, water and air.

EWG’s review bolsters the findings and ongoing research of the Halifax Project, a collaboration of more than 300 scientists from around the world who are investigating new ways in which combinations of toxic chemicals in our environment may cause cancer. While most cancer research focuses on treatment, the Halifax Project and EWG’s Rethinking Cancer initiative are looking at prevention by reducing people’s contact with cancer-causing chemicals.

“The presence of a toxic chemical in our bodies does not necessarily mean it will cause harm, but this report details the astounding number of carcinogens we are exposed to in almost every part of life that are building up in our systems,” said Curt DellaValle, author of the report and a senior scientist at EWG. “At any given time some people may harbor dozens or hundreds of cancer-causing chemicals. This troubling truth underscores the need for greater awareness of our everyday exposure to chemicals and how to avoid them.”

EWG estimated that a small subset of the chemicals inventoried in the report were measured at levels high enough to pose significant cancer risks in most Americans ––risks that generally exceed Environmental Protection Agency safety standards. But those estimates are only for individual chemicals and do not account for a question scientists and doctors are increasingly concerned about––how combined exposures to multiple chemicals may increase risk?

EWG’s inventory comes at an auspicious moment for the issue of cancer and chemicals. Last week Congress passed the first reform in 40 years of the nation’s woefully weak toxic chemical regulations, which President Obama is expected to sign soon....“Many of the carcinogens this study documents in people find their way into our bodies through food, air, water and consumer products every day. Dozens of them show up in human umbilical cord blood—which means Americans are exposed to carcinogens before they’ve left the womb,” said EWG President Ken Cook. “We should focus on preventing cancer by preventing human exposure to these chemicals.”

More evidence linking endocrine disrupting chemicals such as butyl paraben, triclocarbon, propyl paraben. with negative health effects (here linked to effects on the pregnancy and baby). It is especially important to try to lower exposure to endocrine disruptors during pregnancy. So read labels on all personal care products and avoid all parabens, phthalates, triclocarban, bisphenol-A (BPA), and triclosan - because what you use on your body will get into your body, From Medical Xpress:

Use of personal care products during pregnancy linked to adverse effects in newborns

A study led by SUNY Downstate Medical Center's School of Public Health presents evidence linking personal care products used during pregnancy to adverse reproductive effects in newborns."The study found a link between women with higher levels of butyl paraben, which is commonly used as a preservative in cosmetics, and the following birth outcomes: shorter gestational age at birth, decreased birth weight, and increased odds of preterm birth," says Laura Geer, PhD, MHS, associate professor in the Department of Environmental and Occupational Health Sciences in the School of Public Health at SUNY Downstate.

The antimicrobial compound, triclocarban, mainly added to soaps, was associated with shorter gestational age at birth. Another common chemical added to lotions and creams, propyl paraben, was associated with decreased body length at birth. The long-term consequences of this are not clear, and, Geer adds, "Findings must be reproduced in larger studies."

Dr. Geer says, "Our latest study adds to the growing body of evidence showing that endocrine-disrupting compounds can lead to developmental and reproductive problems in animals and in humans. Effects observed in previous studies mainly came from animal models only." This study presents evidence of potentially adverse impacts in humans. 

Regulations requiring removal of triclosan from various consumer care products have been in place since 2015 in the European Union, but broader regulatory action by the U.S. Food and Drug Administration and the U.S. Environmental Protection Agency has not ensued.

More on this same story from Environmental Health News:  Soap, makeup additives linked to preterm births, smaller babies

Pregnant women in Brooklyn with high levels of certain compounds used in makeup and soaps were more likely to have preterm births and babies that weighed less, according to a new study. The study, published online last week in the Journal of Hazardous Materials, provides the first evidence that germ-killing and preservative chemicals used in cosmetics and soaps might impact newborns’ health. It also bolsters suspicions that chemicals in soaps and lotions disrupt people’s endocrine systems, which are crucial for reproduction and babies’ development.

From 2007 to 2009, Geer and colleagues tested 185 mothers’ third trimester urine, as well as the umbilical cord blood of 34 of them, for a suite of different parabens, used mostly in cosmetics, and triclosan and triclocarban, which are used as antimicrobials in soaps. The mothers were from the University Hospital of Brooklyn’s Prenatal Clinic.

The chemicals, especially the parabens, are common: According to the Environmental Working Group’s Skin Deep database, butylparaben is used in 2,245 personal care products, propylparaben is used in 7,212, and triclocarban is used in 21.

The results don’t prove that the chemicals are behind the birth problems. While scientists know the chemicals have some biological activity, the amount of exposure that could cause problems remains unclear.  Animals exposed to the chemicals have had some reproductive impacts. In rats, triclocarban impacted male sex organ development in a 2008 studyParaben exposure decreased male rat sperm counts and efficiency in a 2002 study. One of the most studied endocrine disrupting chemicals, bisphenol-A or BPA, has been linked to multiple birth defects....Except for some color additives, the U.S. Food and Drug Administration does not regulate cosmetic ingredients.