The Ten Toxic Truths: The science behind what we know (and don't know) about toxic chemicals

Views 60

Ten Toxic Truths: What we know (and don't know) about toxic chemicals

The is adapted from an article published in Organic Gardener Magazine April, 2016

Its A Toxic World

It is widely recognised that the greatest cause of death and disease in the world is chronic disease caused by modern lifestyles. The world is in the grip of an epidemic of cancer, obesity, metabolic, cardiovascular and lung disease, along with dementia, neurodevelopmental and reproductive disorders that are fuelled by a high intake of sugar, fat, salt, alcohol and tobacco, and lack of physical activity [1]. In addition to this voluntary consumption, the entire human population is involuntarily exposed to a toxic cocktail of industrial chemicals, (also known as toxicants, xenobiotics) which are routinely found in our air, water, soil, food, breast milk and other human tissue, and our indoor and outdoor environments. 

The impact of industrial chemicals on human health has been recently highlighted by the World Health Organisation, which forecasts a “tidal wave of cancer” [2]. Meanwhile, public health researchers suggest we are experiencing a “silent pandemic of neurodevelopmental disorders” and a “chemical brain drain” brought about by the exposure of an entire generation to industrial chemicals [3].

Understanding Our Toxic Legacy – The Ten Toxic Truths

Since the 16th Century when Paracelsus first stated “the dose makes the poison”, it has been thought the toxicity of a substance depends on dose. This idea forms the basis of risk assessments and the current regulation of chemicals, however; while it is true that toxicity is related to dose, this truth this is far from complete.

We now know that toxicity is not just about dosage; it is also related to the type of chemical, the timing of exposure, the combination of chemicals and individual risk factors such as genetic susceptibility, demographics and current health status. It is therefore difficult to know the specific health effects of any single toxicant and this uncertainty is compounded by modern life leading to increasing exposure to a wide range of industrial pollutants, electromagnetic radiation, noise, and psychological stress, amid a confluence of global financial, climate and social crises. The relationship between chemical exposures and human health are highlighted by ten ‘toxic truths’ that describe the extent of our knowledge and its current limitations.

TOXIC TRUTH 1

Everyone Is Affected

Toxic chemical exposure has become an inevitable part of modern life and everyone is affected. Since the advent of the industrial revolution, industrial chemicals have permeated the globe and it is clear that the world will never return to conditions that existed prior to the industrial and chemical revolutions. Toxic chemicals have entered every habitat and ecosystem on earth, from the most arid deserts to the deepest seas, and virtually all living creatures now contain pollutants at or near harmful levels. Many toxic chemicals are dispersed as atmospheric aerosols and distributed throughout the world through long-range environmental transport and billions of tons of chemicals and plastics have entered the oceans so that microplastic particles can be found in every litre of ocean water and it is predicted that by 2050 there could be more plastic in the ocean than fish.

Toxic chemicals are pervasive in our food, soil, air, water and indoor environments as well as in all human tissues including cord blood and breast milk. The world’s most comprehensive assessment of human chemical exposures is currently conducted as part of the National Health and Nutrition Examination Survey (NHANES) by the US Centre for Disease Control, Of the many tens of thousands of industrial chemicals, the most recent NHANES report examined only 212 chemicals and found chemicals such as Polybrominated diphenyl ethers (PBDEs), used as fire retardants, and Bisphenol A (BPA), a component of epoxy resins and polycarbonates, in the vast majority of participants [4].

TOXIC TRUTH 2

The Full Extent Is Unknown

While we are all chronically exposed to a toxic cocktail of industrial pollutants, the full impact of industrial chemicals on human health remains unknown. There are more than 140,000 industrial chemicals commercially produced with more than 3,000 produced in high volume and many tens of thousands more being inadvertently produced from industrial processes. Yet while the number of industrial chemicals increases every year, in most cases it is not possible to determine a chemical’s ‘safe level’, or ‘toxicity threshold’ and even when levels are measured, it is often difficult to interpret their clinical significance.

The measurement of the body's toxic load is still an emerging science [5, 6]. There are very few laboratories that currently have the facilities to perform comprehensive measures of toxic chemicals and as yet, there are no general assessment measures that doctors can request to assess the ‘toxic load’ or ‘body burden’ of their patients. Thus, even though the signs and symptoms of overdose or overt toxicity are known for some compounds, the relationship between toxic load, individual susceptibility, clinical symptoms and chronic disease is complex and far from understood. Furthermore, only a few countries such as the US [7, 8], Canada [9]and Germany [10]have programs that aim to monitor or assess toxic chemical exposure in the general population.

TOXIC TRUTH 3

Tiny Doses Can Have Big Effects

In the past it was thought that dose-response curves were linear, displaying a direct relationship between dose and toxicity. It is now known that dose response curves can be non-linear or ‘non-monotonic’ when chemicals disturb the body’s regulatory processes rather than just impacting on target organs or tissues. By disrupting the endocrine system the potential to reap metabolic havoc is greatly increased and extremely small exposures, orders of magnitude below recognised safety levels, can have dramatic effects.

The hazards of endocrine disrupting chemicals and their potential for irreversible, latent effects was brought into the public spotlight by Theo Colburn and Pete Myers in the mid 1990’s with the book “Our Stolen Future”. This book highlighted the science that shows that currently used chemicals can impair reproduction, behaviour, intellectual capacity and the ability to resist disease in current and future generations and suggested that: world-wide exposure to endocrine disruption has thrust everyone into a large-scale, unplanned, unintended experiment with health, the outcome of which may not be known for generations.

While at the time of its release this book was seen by many as alarmist, a recent joint report from the World Health Organization and United Nations Environment Program on the “state-of-the-science of endocrine disruptors” confirms many of its findings and suggests that exposure to industrial chemicals with endocrine disrupting actions are contributing to the global increase in obesity, cancer, psychiatric diseases, birth deformities, ADHD and neurodevelopmental problems in children, with current findings being 'the tip of the iceberg' [11].

TOXIC TRUTH 4

Biomagnification Occurs Up The Food Chain

Many toxic chemicals are fat soluble and last for decades in the environment where they undergo biomagnification up the food chain. The persistence and toxicity of DDT and other Persistent Organic Pollutants (POPs) was first brought to public attention in 1962 by Rachel Carson’s book “Silent Spring” [12]. This book inspired a grassroots environmental movement that led to the creation of the U.S. Environmental Protection Agency and in May 2004 the Stockholm Convention on POPs first came into effect. This Convention banned the use of nine persistent pesticides along with dioxins, furan and polychlorinated biphenyls (PCBs). The so-called legacy chemicals were all known to persist in the environment; undergo long-range environmental transport; be toxic to humans; and biomagnify up the food chain.

Even though most persistent pesticides are now banned in agriculture, these chemicals now permeate the global environment and lodge in the fatty tissue of animals where they biomagnify millions of times as they travel up the food chain. Being a precious biological resource fat is seldom excreted, except for special situations such as breastfeeding where valuable fat, along with fat-soluble pollutants, is transferred to infants who sit at the very top of the food chain. Thus,  studies have shown that infants can consume DDT and other POPs at levels greater than the Acceptable Daily Intake (ADI), which is calculated for a 70kg adult [13].

POPs are also adsorbed by micro-plastics in the oceans and are found in high concentrations in marine mammals. This has led to beached whales being classified as toxic waste and documented in studies of whale earwax, which like tree rings, gets laid down sequentially over a whale’s life and provides a record of the whale’s and ocean’s growing toxicity[14].

TOXIC TRUTH 5

Chemicals Cocktails Are Synergistic

While exposure to individual toxic chemicals can be harmful, exposure to chemical mixtures is far more harmful. It has been shown that chemical cocktails can produce ‘something from nothing’, with toxic mixture effects arising even when the level of each contaminant in the mixture is below its specific NOAEL (No Observable Adverse Effect Limit) and therefore causes no effect by itself. Such mixture effects are not accounted for when assessing chemical safety, which is tested one chemical at a time, if at all.

A 2009 “State of the Art Report on Mixture Toxicity” commissioned by the European Union states that; “there is consensus in the field of mixture toxicology that the customary chemical-by-chemical approach to risk assessment might be too simplistic. It is in danger of underestimating the risk of chemicals to human health and to the environment.”

While mixture toxicity is currently not accounted for in chemical risk assessments, it is actively used in pesticide formulations to increase their potency. In order to kill pests, pesticides contain active ingredients with inherent toxicity, yet when pesticides are packaged and used they are prepared as ‘formulations’. These formulations include the addition of often unnamed and unlabelled adjuvants that are designed to make the active ingredient more potent by acting as surfactants and cell penetrants. While these so-called 'inert' adjuvant chemicals are excluded from safety testing, recent research suggests they are far from inert and make formulations such as Round-up, hundreds of times more toxic than the active ingredient alone [15].

TOXIC TRUTH 6

Bioaccumulation Occurs Over The Lifespan

Exposure rates of fat-soluble chemicals often exceed the excretion rate leading to accumulation in fatty tissue over the lifespan. This exposure begins in the womb with fat-soluble chemicals present in umbilical cord blood crossing the placenta and lodging in fetal fat, which is mainly in the developing brain. This is documented in numerous reports that suggest children are now born “pre-polluted” [16-18]. Once born, children who consume breast milk sit at the top of the food chain, with first-born children receiving a greater contaminant load due to exposure to their mother’s lifetime accumulation.

Throughout the lifespan combinations of persistent chemicals accumulate in fatty tissue such as the brain, breast, prostate and bone marrow, which are often the tissues that develop cancers in later years. In addition to persistent fat-soluble chemicals, there are other many water-soluble endocrine disrupting chemicals such as BPA and organophosphate (OP) pesticides that are ingested continually throughout the lifespan making them ‘pseudo-persistent’.

The widespread contamination of human populations with POPs and other industrial pollutants has been suggested to play an important role in the worldwide obesity epidemic [19]. This may occur through multiple pathways as many pollutants have been shown to function as ‘obesogens’ that damage the body’s natural weight control mechanism and act in synergy with other factors to exacerbate the development of obesity. The dramatic global rise in centripetal obesity may be an example of the dictum; ‘the solution to pollution is dilution’. This dictum, which is given credence by public health officials, suggests that with no effective way to rid itself of POPs, the body packs on fat to store them out of harm’s way thereby diluting their levels in the brain and other vital organs.

TOXIC TRUTH 7

Windows Of Development Are Critical

The toxic effects of chemical exposure during critical periods can be irreversible, yet remain hidden until later in life. This became tragically evident in the 1970s with the birth of thousands of children without limbs and other birth defects after being exposed in utero to thalidomide. More recently, in-utero exposure to OP pesticides has been shown to relate to children’s intellectual development in later life [20].

TOXIC TRUTH 8

Effects Are Trans-Generational

Parental exposure to industrial chemicals can affect offspring and future generations. Many chemicals interfere with biochemical and endocrine pathways, induce genetic and developmental abnormalities, and produce trans-generational epigenetic effects that can influence all aspects of an individual’s life history and lead to abnormalities in the 3rd or 4th generation post-exposure. This has recently been demonstrated experimentally with a single exposure to a common-use fungicide being shown to alter the physiology, behaviour, metabolic activity, and brain development in offspring three generations later and alter how they perceive and respond to a stress [21].

TOXIC TRUTH 9

Risk Is Unequal, Unjust And Greater For The Young

The health risks of chemical exposures differ according to individual risk factors that include health status, physiology and genetics as well as demographic and social differences. Children are most vulnerable due to their higher dietary exposure, contact with the ground, hand-to-mouth behaviour, higher metabolic activity, immature organ systems and a longer latency period for developing disease so that exposures during sensitive windows of development lead to lifelong consequences [22].

The US-based Pesticide Action Network recently published a review of the scientific literature titled "Generation in Jeopardy: How pesticides are undermining our children’s health and intelligence”, which reports on the many studies that demonstrate that pesticide exposure compromises children's cognitive function and leads to later chronic disease [23]. Similarly, a risk-assessment study based on dietary and food toxin data suggests that all Californian children are exposed to toxins in their diets at levels that cause cancer or other adverse health effects [24].

TOXIC TRUTH 10

Exposure Is Unequal, Unjust And Accidents Happen

Everyone is exposed to industrial pollutants, yet exposure risk is not equal. Exposures vary with age, income, education, occupation, location, lifestyle, public policy and proximity to industrial activity and accidents. People living in poverty and lower socioeconomic conditions often have the greatest exposure, which then compounds the effects of wealth inequality [25]. This makes environmental justice an important issue.

Industrial accidents raise further justice issues as catastrophic accidents have inadvertently exposed vast populations of humans and wildlife to industrial pollutants. These accidents have occurred at every stage of the chemical-production cycle including mining (BP oil spill); transport (Exxon Valdez); manufacture (Bhopal); use (Fukushima and Chernobyl); and disposal (Love Canal) and these accidents are often associated with delayed and inadequate compensation and remediation measures.

Minimising Exposures

The vast increase in chemical exposures associated with modern lifestyles has greatly outpaced our knowledge of their consequences. It seems that as individuals and as a society we must address the question: ‘What level of toxic chemicals are we willing to allow in our bodies and our children for the sake of our modern lifestyles and cheap, abundant, industrially-produced food?

Considering all the issues raised by ‘the ten toxic truths’ it is unlikely that we can ever know exactly how damaging our individual or family’s toxic load is, or will be. While more research and greater awareness are certainly needed, the best option is to adopt the precautionary principle, which suggests, that in the presence of incomplete knowledge, it is; ‘better to safe than sorry’. Thus, we must try to minimise chemical and other stressful exposures wherever possible, and rather than becoming despondent, we need to become more aware and vigilant. We also need to put pressure on governments and companies to reduce the amount of chemicals in the environment and deepen of our scientific understanding of the extent and impact of chemical exposures on human health.

On a dietary level, eating less non-organic animal products is a good start, as animals tend to accumulate POPs in their fat and thereby magnify POPs lurking in animal feed and the environment. As for reducing exposure to the many non-persistent pollutants such as organophosphate pesticides (OPs), glyphosate and other pesticides and food packaging materials that commonly contaminate food – eating organic food (with no plastic packaging) is the most obvious solution.

Research in children and adults has shown that a mostly organic diet can dramatically reduce levels of OP pesticides (Curl 2003, Lu and Toepel 2006, Oates 2014). Urinary glyphosate levels are also reported to be significantly less in healthy people and people who eat organic food compared to chronically diseased people (Krüger 2014). The American Academy of Pediatrics Committee on Nutrition and Council on Environmental Health recently published a position paper titled ‘Organic Foods: Health and Environment Advantages and Disadvantages’ that reported: “In terms of health advantages, organic diets have been convincingly demonstrated to expose consumers to fewer pesticides associated with human disease.”

Positive actions we can take to rid ourselves – and the environment – of toxic chemicals include:

·         Understand the problem and help raise awareness.

·         Eat unpackaged, mainly plant-based foods consisting of Seasonal Local Organic Whole (SLOW) food wherever possible.

·         Avoid plastics, even BPA-free because of the unknown toxicity of replacements.

·         Avoid personal care and household products that contain artificial fragrance and other petrochemicals.

·         Open up your body’s channels of elimination by supporting healthy liver, bowel and kidney function and through regular exercise and sweating.

·         Maximise your nutritional status through the use of herbs and spices such as tulsi and turmeric, along with foods high in phytonutrients.

 

Toxicity depends on:

·         The type of chemical

·         The dose of chemical

·         The timing of exposure

·         The combination of exposures

·         Individual risk factors

Ten Toxic Truths

1.    Everyone is affected

2.    The full extent is unknown

3.    Tiny doses can have big effects

4.    Biomagnification occurs up the food chain

5.    Chemical cocktails are synergistic

6.    Bioaccumulation occurs over the lifespan

7.    Windows of development are critical

8.    Effects are trans-generational

9.    Risk is unequal, unjust and greater for the young

10.  Exposure is unequal, unjust and accidents happen

 

Ten Toxic Truths -Overview

1) Everyone is affected

Toxic chemicals are pervasive and are distributed through long-range environmental transport so that all living things contain pollutants at or near harmful levels. Toxic chemicals are found in all human tissues and in food, soil, air, water and indoor environments.

2) The full extent is unknown 

Toxic chemicals are often invisible and have latent effects. Over 80,000 chemicals are produced commercially and industrial processes inadvertently create many more. Most chemicals are not tested for toxicity and very few are routinely tested for in human tissue. 

3) Tiny doses can have big effects

Dose responses can be non-linear with extremely small doses of endocrine disrupting chemicals (EDCs) contributing to the global increase in obesity, birth deformities, cancers, psychiatric diseases and neurodevelopmental problems with current findings being “the tip of the iceberg”.

4) Bio-magnification occurs up the food chain

Persistent organic pollutants (POPs) last for decades in the environment, accumulate in fatty tissue and magnify up the food-chain. Bio-magnification leads to much higher concentrations in predatory species and human infants who sit at the top of the food-chain.

5) Chemicals cocktails are synergistic

Exposure to chemical mixtures is more harmful than individual chemicals. Mixture effects can produce ‘something from nothing’, with toxicity arising even when individual chemical concentrations have no effect, yet chemicals are tested for safety individually, if at all.

6) Bioaccumulation occurs over the lifespan

Exposure rates of fat-soluble chemicals often exceed the excretion rate leading to accumulation over the lifespan in fatty tissue such as the brain, breast, prostate and bone marrow. This accumulated body burden crosses the placenta and targets the fetal brain.

7) Windows of development are critical

The toxic effects of exposure during critical periods can be irreversible, yet remain hidden until later in life. Early exposure can impair intellectual development and metabolism and foster the development of metabolic syndrome, cancer and other chronic diseases.

8) Effects are trans-generational

Parental exposure to industrial chemicals affects offspring and future generations. Industrial chemicals can induce genetic and developmental abnormalities and transgenerational epigenetic effects that can lead to abnormalities in the third and fourth generation post-exposure.

9) Risk is unequal, unjust and greater for the young

Risks vary with physiology, genetics, demographics and income. Children are most vulnerable due to higher dietary exposure, contact with the ground, hand-to-mouth behavior, higher metabolic activity, immature organ systems and a longer latency period for developing disease.

10) Exposure is unequal, unjust and accidents happen 

Exposure is not equal and varies with age, income, education, occupation, location, lifestyle, public policy and proximity to industrial accidents. Accidents that inadvertently expose vast populations to toxic chemicals happen at every stage of the industrial chemical lifecycle.

 

 

 

 

References

 

1.       World Health Organisation, Preventing Chronic Diseases: A vital investment : WHO Global Report. 2005, Department of Chronic Diseases and Health Promotion, World Health Organization: Geneva.

2.       International Agency for Research On Cancer, World Cancer Report 2014, B.W. Stewart, Wild, C.P.,, Editor. 2014, World Health Organisation: Geneva.

3.       Grandjean, P., Landrigan, P.J., Neurobehavioural effects of developmental toxicity. The Lancet, 2014. 13(3): p. 330-338.

4.       Centers for Disease Control and Prevention, Fourth National Report on Human Exposure to Environmental Chemicals. 2009, US Department of Health and Human Services.

5.       Committee on Human Biomonitoring for Environmental Toxicants., Human Biomonitoring for Environmental Chemicals  2006: National Research Council

6.       Sexton, K., Needham, LL., Pirkle, JL., Human Biomonitoring of Environmental Chemicals. American Scientist, 2004. 92: p. 38-45.

7.       Calafat, A., Ye, X., Wong, LY., Reidy, JA., Needham, LL., Exposure of the U.S. population to bisphenol A and 4-tertiary-octylphenol: 2003–2004. Environ Health Perspect, 2008. 116: p. 39-44.

8.       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 2104. 11(2): p. 2125-2147.

9.       Tremblay, M., M. Wolfson, and S. Connor Gorber, Canadian Health Measures Survey: rationale, background and overview. Health reports / Statistics Canada, Canadian Centre for Health Information = Rapports sur la sante / Statistique Canada, Centre canadien d'information sur la sante, 2007. 18 Suppl: p. 7-20.

10.     Schultz, C., Angerer, J., Ewers, U., Heudorf, U., Wilhelm, M., , International Journal of Hygiene and Environmental Science. Revised and new reference values for environmental pollutants in urine or blood of children in Germany derived from the German Environmental Survey on Children2003-2006(GerESIV), 2009. 212: p. 637-647.

11.     WHO/UNEP, State of the science of endocrine disrupting chemicals - 2012: An assessment of the state of the science of endocrine disruptors prepared by a group of experts for the United Nations Environment Programme (UNEP) and WHO. 2013, World health Organisation & United Nations Environment Program: Geneva.

12.     Carson, R., Silent Spring. 1962, Houghton Mifflin.: New York,.

13.     Quinsey, P.P., Donohue, D.C., Ahokas, J.T., Persistence of Organochlorines in Breast Milk of Women in Victoria, Australia. Food Chem Toxicol., 1995. 33(1): p. 49-56.

14.     Trumble, S.J., Robinson, E.M., Berman-Kowalewski, M., Potter, C.W., Usenko, S., Blue whale earplug reveals lifetime contaminant exposure and hormone profiles, , doi:10.1073/pnas.1311418110. Proceedings of the National Academy of Sciences, 2013. 110(42): p. 16922–16926.

15.     Mesnage, R., Defarge, N., Spiroux de Vendômois, J., & Séralini, G.-E., Major pesticides are more toxic to human cells than their declared active principles.  . BioMed Research International, 2014: p. 1-15.

16.     Environmental Defence, Pre-polluted: A report on toxic substances in the umbilical cord blood of Canadian newborns. . 2013: Toronto.

17.     Environmental Working Group, Body Burden: The Pollution in Newborns. . 2005: Washington, DC.

18.     WWF, A present for life: hazardous chemicals in umbilical cord blood. 2005: Amsterdam.

19.     Baillie-Hamilton, Chemical toxins: a hypothesis to explain the global obesity epidemic. J Altern Complement Med. , 2002. 8(2): p. 185-92.

20.     Bouchard, M., Chevrier, J., Harley, KG., Kogut, K., Vedar, M., Calderon, N., Trujillo, C., Johnson, C., Bradman, A., Barr, DB., Eskenazi, B., Prenatal exposure to organophosphate pesticides and IQ in 7-year-old children. Environ Health Perspect, 2011. 119(8).

21.     Crews, D., Gillette, R., Scarpino, S.V., Manikkam, M., Savenkova, M.I., Skinner M,K. , Epigenetic transgenerational inheritance of altered stress responses. Proc Natl Acad Sci, 2012. 109(23): p. 9143-8

22.     Landrigan, P., Garg, A., Children are not little adults, in Children’s health and the environment: A global perspective - A resource manual for the health sector, J. Pronzczuk de Garbino, Editor. 2005, World Health Organization: Geneva.

23.     Schafer, K., Marquez, EC. et al., Generation in Jeopardy: How pesticides are undermining our children’s health and intelligence. 2013, Pesticide Action Network: Oakland CA.

24.     Vogt, R., et al., Cancer and non-cancer health effects from food contaminant exposures for children and adults in California: a risk assessment. Environmental Health, 2012. 11(1): p. 83.

25.     Wright, R.J., Moving towards making social toxins mainstream in children's environmental health. Curr Opin Pediatr, 2009. 21(2): p. 222-9.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of GreenMedInfo or its staff.
Sayer Ji
Founder of GreenMedInfo.com

Subscribe to our informative Newsletter & get Nature's Evidence-Based Pharmacy

Our newsletter serves 500,000 with essential news, research & healthy tips, daily.

Download Now

500+ pages of Natural Medicine Alternatives and Information.

This website is for information purposes only. By providing the information contained herein we are not diagnosing, treating, curing, mitigating, or preventing any type of disease or medical condition. Before beginning any type of natural, integrative or conventional treatment regimen, it is advisable to seek the advice of a licensed healthcare professional.

© Copyright 2008-2022 GreenMedInfo.com, Journal Articles copyright of original owners, MeSH copyright NLM.