Common Chemical Pollutants Causing a Lot of Ill Health

Abstract

Due to industrialization and inadequate controls on release of manufacturing chemicals into the environment and into the products being made, the entire population is constantly being exposed to a wide variety of chemical pollutants. The key question, of course, is their safety. The most acutely damaging ones have been progressively limited. However, virtually all safety research is on single toxins and very little of it looks at the impact of chronic exposure, especially chronic exposure to multiple chemicals simultaneously. This editorial discusses the clinical significance of 4 of the chemicals (acrolein, acrylamide, perchlorate, and phthalates) found most often in samples doctors send to labs for analysis. The research clearly demonstrates that these chemicals in a dose-dependent manner disrupt physiology, impair health, and increase risk for common diseases.

Introduction

Several months ago, I asked Great Plains Laboratory (GPL) for a list of the environmental chemicals they were finding most often in the samples doctors were sending them. I have for almost 2 decades been extensively studying the environmental toxin research and carefully reviewing the findings of the Center for Disease Control’s (CDC’s) various agencies which develop government policy on environmental toxins. I found so much research and agency findings of clinical importance that I have written about them in many editorials. While the CDC’s Agency for Toxic Substances and Disease Registry (ATSDR) has a toxic substance priority list, I was curious about which chemicals GPL was actually finding in their thousands of tests. I was surprised to learn that there was no overlap between the ATSDR’s list (see Table 1) and what GPL is actually measuring (see Table 2). This priority list is not a list of “most toxic” substances, but rather a prioritization of substances based on a combination of their frequency, toxicity, and potential for human exposure at toxic waste dumps to help Congress determine environmental priorities.

Table 1.

CDC’s Agency for Toxic Substances and Disease Registry Substance Priority List (In decreasing order)¹

Arsenic Lead Mercury Vinyl chloride Polychlorinated biphenyls (PCBs) Benzene Cadmium Benzo(a)pyrene Polycyclic aromatic hydrocarbons (PAHs) Benzo(b)fluoranthene Chloroform Aroclor 1260 DDT, P,P’- Aroclor 1254 Dibenzo(a,h)anthracene

Table 2.

GPL List of Most Commonly Found Chemical Toxins

Most common: Acrolein Acrylamide Bromopropane MTBE (methyl tert-butyl ether) Perchlorate

Second most common: Phthalates Styrene Xylene

There are, of course, many possible explanations for the discrepancy. I’ve listed some possibilities in Table 3, and I suspect the reader can think of several more. Nonetheless, if these chemicals found most by GPL are indeed the most common chemicals polluting people, we need to understand if they are clinically significant.

Table 3.

Possible Reasons for Discrepancy

CDC includes in their prioritization toxic waste dumps CDC overweighs industrial exposure CDC prioritizes toxins with historic, well-established overt disease associations The safety/threshold standards are distorted by the pervasive nature of these chemical toxins—no healthy/low-toxin control groups The chemicals GPL measures have limited disease associations GPL is primarily testing sick people

Since the CDC is responsible for making policy recommendations to the President and Congress, it is not surprising they include toxic waste dumps and prioritize toxins with the strongest disease associations. As I looked at the research on these chemical toxins, a pattern emerged that I think not only explains this discrepancy but also highlights the huge philosophical chasm between focusing on disease and focusing on health and function. While the chemical toxins on the Substance Priority List have disease associations, the much bigger problem is that they impair physiological function, leading to ill health and increased susceptibility to most common diseases.

Below I present alphabetically the 4 most common chemical toxins found at GPL with the strongest research on harm in humans. Presented for each is Persistence, Sources, Mechanisms of Damage, Diseases Caused, Primary Route of Detoxification, Assessment, and Elimination. One area I do not cover is transgenerational effects. In the long run, the damage to succeeding generations may be the worst and most worrisome problem with these toxins.

The Chemical Toxins Found by GPL With the Most Research on Human Harm

Acrolein is the simplest unsaturated aldehyde and is modestly persistent in humans with a half-life of 7-10 days.² It accounts for the smell of burnt fat and exposure is extremely common. The Environmental Protection Agency (EPA) considers it a high-priority air and water toxin, though it did not reach the CDC priority list. Acrolein is released into the environment when synthesized, emitted from combustion processes (smoking, fossil fuels), used as a contact herbicide/biocide, and is commonly found in foods and beverages such as coffee, alcohol, cheese, donuts, and most cooked products.³

Acrolein is detoxified by glutathione—and thus depletes it; it forms protein adducts, which disrupt function; impairs mitochondrial and endoplasmic reticulum function; and forms adducts with DNA, but their role in cancer is controversial.⁴ The oxidative damage it induces in lipoproteins plays a big role in foam cell formation in the arteries which are further damaged by its suppression of endothelial nitric oxide synthase (eNOS) activation, attenuation of endothelial cell migration, blocking vascular endothelial growth factor, and reducing circulating levels of angiogenic cells.⁵ Acrolein increases triglycerides and high sensitivity C-reactive protein (hs-CRP), and lowers high-density lipoprotein cholesterol (HDL-C).⁶ Not surprising that body load directly correlates with increased risk of many aspects of cardiovascular disease.⁷ Figure 1 shows direct, dose-dependent correlation with hypertension.

Figure 1.

Acrolein Body Load Correlates With Blood Pressure⁵

Body load of acrolein also correlates with increased risk of dementia and those in the top quartile have a 3.36-fold increased risk for diabetes.^8,9

Acrolein is measured in the urine. Best intervention is avoidance and glutathione support.

Acrylamide is a vinyl-substituted primary amide that is synthesized for use as a precursor in the production of polyacrylamides. Polyacrylamides are widely used water-soluble thickeners and flocculation agents. Acrylamide also forms in the burnt areas of food, particularly starchy foods like potatoes and grains, when cooked at temperatures above 248°F. It is formed through the Maillard reaction which leads to the color, flavor, and aroma changes that characterize cooked foods. About one-third of calories in the typical American diet come from foods contaminated with acrylamide.¹⁰ Table 4 lists the acrylamide content of commonly consumed foods.

Table 4.

Acrylamide Content (PPB) of Common Foods¹¹

Sweet Potato Chips with Sea Salt Crinkle Cut	8440
Popchips Potato Sea Salt	3060
House of Herbs Blackstrap Molasses	2160
MiCostenita Papitas Casera Homemade Potatoes	1770
Nabisco Ginger Snaps	1450
Colton’s Steak House Trail Potatoes Potato Skins	1440
Lay’s Classic Potato Chips	1410
Better Made Potato Chips Original	1370
Nathan’s Famous Jumbo Crinkle Cut French Fries! (fried)	1330
Logan’s Road House Loaded Potato Skins	1330
Giant Brand O’Brien Style Hash Browns (fried)	1290
Woody’s Grille Seasoned Waffle Fries	1260
Michael Season’s Thin & Crispy Lightly Salted Potato Chips	1230
General Mills Corn Chex	1210
Ore Ida Mini Tater Tots (fried)	1170
IHOP Hash Browns	1090
Price First 100% Instant Coffee	1080
Good Health Veggie Chips Sea Salt	1050
Red Robin Sweet Potato Fries	1030
Grub Burger Bar Sweet Potato Fries	1020

Acrylamide is a non-persistent toxin (half-life of 2-24 hours depending upon the metabolite measured).¹² It is found in 99.9% of the population and levels are twice as high in smokers.¹³

Like so many of these chemicals we’re commonly exposed to, determining the clinical impact is challenging since exposure is ubiquitous. The research shows correlation with childhood disabilities and all-cause mortality. A comparison of top to bottom quartiles of exposure shows statistically significant correlation with cancer mortality (2.07-4.43, depending upon metabolite measured) and cardiovascular death (1.61).^14-16

Acrylamide is a known neurotoxin and strong research shows that industrial exposure causes neuropathies, numbness of the hands and feet, gait abnormalities, muscle weakness, ataxia, skin abnormalities, and, in some cases, cerebellar alterations.¹⁷ However, the neurological impact in the general population is less clear.

Some very limited research suggests that vitamin D helps ameliorate the damage of acrylamide.¹⁸

Acrylamide is mainly detoxed by glutathione conjugation.

Acrylamide is measured in the urine. Best intervention is avoidance and vitamin D and glutathione support.

Perchlorate (ClO₄^-) is a very strong oxidant that is non-persistent (8-hour half-life) in humans but is very persistent in nature. It is used in rocket fuel, fireworks, highway flares, and to control static electricity in food packaging. Perchlorates widely contaminate the environment. Industrial waste is a major source, although it can be produced naturally, and some inconsistent research suggests that chlorination of water can produce it as well. Human exposure is through inhalation (factory workers and people living in cities with smog) and consumption (water and food). The average public water supply contains 1.2 PPB while 4.1% of these supplies exceed the public health limit of 4 PPB.¹⁹

Perchlorate is readily absorbed, poorly metabolized in humans, and mostly excreted unchanged in the urine and, unfortunately, in breast milk as well. The main physiological problem is that it binds to iodine and is thus classified as a goitrogen. This is why historically potassium perchlorate was used to treat hyperthyroidism. However, it was eventually replaced by other drugs due to severe adverse events. Perchlorate dose dependently correlates inversely with thyroid hormone levels and positively with TSH.²⁰ However, it is only associated with overt disease in those with low levels of iodine and/or substantial exposure to other goitrogens. Unfortunately, iodine deficiency is very common and is becoming more prevalent. Of particular concern is the worrisome research showing, for example, that 23% of pregnant women in Lansing, Michigan—a historically iodine deficient region of the United States—are at risk for iodine deficiency. Iodine consumption in the United States has decreased 50% since 1970.²¹ Worldwide, the numbers are even higher for insufficient iodine intake—35% of the general population.²²

Its primary disease association is hypothyroidism. However, the research is inconsistent with only 59% of studies showing a correlation between perchlorate levels and clinical hypothyroidism. This is a good example of defining a toxin as of low concern because of a lack of solid disease causation while ignoring the huge physiological implications. Figure 2 illustrates well the multifactorial nature of perchlorate toxicity.

Figure 2.

The Contributory Factors in Perchlorate-induced Hypothyroidism¹⁹

Perchlorate is a good example of the complexity of determining the disease associations of the many chemicals humans have exposed themselves to. Very clearly its toxicity is determined not only by dose, but by other critical factors such as iodine status and the exposure to other goitrogens.

Best measure is urine. Best intervention is avoidance, limiting goitrogen intake, and ensuring optimal iodine intake.

Phthalates are a family of organic chemicals used as plasticizers (to increase flexibility, transparency, and durability) and for multiple manufactured product purposes, such as to solubilize and stabilize fragrances in cosmetics. They are short-term toxins (half-life < 24 hours), but exposure is relentless. Diet is the main source of phthalates as they easily contaminate fatty foods such as milk, butter, and meats when stored in plastic containers. Diethyl phthalate and dibutyl phthalate are especially common in health and beauty aids (HABAs), except in Europe where they have now been banned due to the very large amount of research showing their toxicity, regardless of the source.

In general, phthalates are organized into 2 categories: high-molecular-weight (HMW) or low-molecular-weight (LMW) compounds depending upon the size of the R and R’ chains. High molecular weight phthalates come mainly from diet while the low molecular ones are primarily from non-food sources such as HABAs and plastics from which they are easily released.

Fast foods are a huge source of phthalates. One study collected hamburgers, fries, chicken nuggets, chicken burritos, cheese pizza, and gloves from restaurants and analyzed them for 11 chemicals.²³ DEHT (this is technically a non-phthalate plasticizer but with similar physiological disruption) was found at the highest concentrations in both foods (2.5 mg/kg) and gloves (28-37% by weight)! I found the latter particularly worrisome since I had assumed that by wearing gloves I would decrease chemical exposure—but they emit plasticizers! Median DEHT concentrations were significantly higher in burritos than hamburgers (6.0 vs 2.2 mg/kg). Surprisingly, DEHT was not detected in fries, and cheese pizza had the lowest levels of most chemicals.

As can be seen in Figure 3, phthalate levels in the urine directly correlate with use of health and beauty aids.²⁴

Figure 3.

Cosmetic Use Increases Phthalates in the Urine²⁴

Phthalates are quickly detoxified through several pathways. Most testing measures only urinary metabolites (typically monoesters) which are then used to interpolate source molecules.

Phthalates are a significant cause of disease. They increase risk of ADHD (OR 2.1-3.7 depending upon metabolite) and lower children’s IQ (6.7 points lower comparing maternal quartiles), decrease male fertility (20%), and greatly increase diabetes (RR 1.48).^25-28

There is some intriguing, but limited, animal research on the use of several vitamins to facilitate excretion and decrease damage. However, extrapolation to humans is problematic and there are essentially no controlled human clinical trials.

Phthalates are measured indirectly via metabolites in the urine. Avoidance is the best intervention.

Conclusion

I think in many ways these very common chemical exposures document the pervasive problem of environmental pollution. They all clearly disrupt physiology in many ways (except perchlorate which appears to disrupt only thyroid). The level of disruption and symptomatology is dose-dependent and only evolves to a disease diagnosis when thresholds are crossed and/or other synergistic factors are present. The current medical perspective appears to assert that environmental toxins are not a problem unless they are shown to clearly cause disease. This illustrates so well the limitations of a disease-centric health care system where loss of physiological function and ill health are essentially ignored until an overt pathology can be demonstrated.

I think this limited disease-centric perspective is why so many of us have been drawn to the natural/functional/integrative/holistic/environmental medicine paradigm. We realize that health is not simply the absence of disease. Rather, health is optimal function. The research is incontrovertible—the hundreds of chemical and metal toxins that saturate our environment damage physiology in many ways, decrease vitality, and increase risk of virtually every disease. The good news is that all these toxins can be avoided, excretion increased, and the damage reversed.

We need to be honest with ourselves—there is no safe level of these poisons. However, I doubt anyone wants to go back to living a short subsistence life in a cave. Industrialization has been a huge boon to the human species (but to few other species). We can’t totally avoid all chemical toxin exposure. However, we can do much, much better at decreasing environmental and human exposure. And we as health care providers need to continue to evolve our environmental medicine diagnostic and therapeutic skills.

Biography

Joseph Pizzorno, ND, Editor in Chief, IMCJ; co-author, Textbook of Natural Medicine; Founding President, Bastyr University; Chair, Board of Directors, Institute for Functional Medicine.