Toxin Exposure & Chronic Disease
During Mary’s interview I noted some key facts that led up to her fatigue, brain fog and diagnosis of a thyroid disorder. She had a history of recurrent chemical exposures as well as head injuries. She played competitive soccer for years, which is the sport most associated with young women getting concussions (U.S. Soccer has officially banned kids younger than 11 from heading the ball due to this). She was also the goalie which meant she was on the turf a lot blocking balls and getting exposed to arsenic from the rubber turf. She is currently working as a hair dresser—another big exposure to chemicals especially associated with hormone disturbances. But the event that pushed her over the edge was when her house and yard were sprayed for bugs after a recent infestation.
How did all this lead to her current illness? Why hadn’t she learned about all these risks before and tried to prevent them? How was I now going to help her start her journey to recovery?
In Part II we will review the literature for toxin exposure and links to chronic disease.
Toxin Exposure & Chronic Disease
A Quick Note on Terminology: Toxins vs. Toxicants
The word “toxin” technically refers only to natural chemicals like those made in our bodies, found in mushrooms, or in snake venom that can affect our health. The word “toxicants,” on the other hand, refers to synthetic chemicals that didn’t exist in the environment before the modern era, like pesticides, phthalates and dioxin (Agent Orange being an example of this). However, most non-technical literature does not make this distinction. For simplicity sake, I will also use the same nomenclature and refer to everything simply as “toxins.”
Heavy metals have been around at least as long as life on Earth. Are they a concern?
Lead exposure in children has been associated with a decreased IQ score as well as neuro developmental issues and bone marrow suppression. For these reasons it was banned from paints in the 70’s and gasoline in the 80’s. Arsenic exposure is associated with different kinds of skin cancer as well as bladder and renal cancer. Arsenic also affects red blood cell formation and is associated with Black Foot Disease (a condition where there is decreased blood flow to extremities leading to eventual gang-green). Arsenic was removed from wood treatment in 2002 and from chicken feed in 2011. Mercury exposure is seen in autoimmunity, diabetes as well as a recent link to Autism. Exposure is also associated with neurological disorders like neuropathy and cognitive decline. Mercury has been removed from thermometers but in some areas is still used in silver dental amalgams.
These are all old, we know these exposure risks that have been eliminated, right? No one gets exposed to these anymore, do we?
The ATSDR was established by Congressional Mandate to research the potential effect of hazardous substances in the environment on the Publics’ health and to report this information to both the Congress and the Public. This organization will routinely rank substances of concern, based on exposure risk and the potential to cause health harms. This is based on both the substances toxicity as well as the probability of exposure.
Yet when is the last time you’ve heard about this or have seen the graphic above (Figure 2) showing the amount of arsenic in common ground water? The areas of greatest concern are represented by the colors red, orange and yellow. The graphic also demonstrates in how many areas of the country the water remains untested.
Lead remains on the ATSDR list at #2. Even though it was banned from paint and gas over 30 years ago, it is still a risk. It still is a major issue in Flint Michigan (see Flint Michigan water crisis of 2014) and it seems like since this sentinel event, every year I learn about another city municipality or school whose water has elevated levels of lead in it.
Cadmium is #7 on the list, and we can see the increased potential for exposure to this since it’s production levels are on the rise. Most exposure in the U.S. comes from cigarette smoking (which thankfully is no longer rising), but the production of Cadmium is not going down. For non-smokers, the most common source is contaminated foods.
Another familiar heavy metal is Mercury at #3 on the list. You know this one, it’s in silver filings, fish, florescent bulbs and used to be in thermometers. Many of our mothers or grandmothers used to play with mercury as children. In the 1920’s it was even a common topical antibiotic. Mercury has been on the EPA’s radar for a while as a potential health concern.
Today’s sources of mercury are a little more obscure. They include that which is a naturally occurring element found in air, soil and water. Also the highly toxic form methyl mercury builds up in fish, shellfish and animals that eat fish. Levels of mercury in the environment are increasing due to discharge from combustion of fossil flues, mining, pulp and paper industries. The graphic to the left shows the levels of mercury deposition from the atmosphere and correlate to the manufacturing/energy producing centers of the U.S.
(Persistent Organic Pollutants)
POPs are synthetic substances that are difficult to degrade and can build up in our bodies over time. Figure 5 lists a few common POPs.
We typically think of clearing these from our bodies in terms of half-life, which is the time required to get 50% of a substance out of our bodies.
A few examples are:
- Dioxins: 7 years (half-life)
- Fire retardants like PBDE: 14 days (half-life)
- Glyphosate: 2–113 days (half-life)
- Lead: 2+years (half-life)
However, this can be misleading because this assumes a one-time exposure. If the exposure is low grade and ongoing (like all the above) then our body accumulates these over time.
But should we even be concerned with these? Aren’t plastics, pesticides, and fire retardants safe?
Let’s find out.
Links to Chronic Disease
Several studies have shown prenatal exposure to POPs associated with poor brain function and memory, as well as a seven-point loss of IQ. But the larger concern is that 25% of pregnant women in the U.S. have levels of these substances exceeding the median acceptable level. Children with these higher levels also have a two-fold increased risk for developing ADHD and less working memory. But what may the most concerning statistic is that almost 100% of homes surveyed had levels of POPs on their floors.
Another POP called chlorpyrifos has been associated with multiple neurological effects on infants. These include lower birth size and weight, small head size, abnormal reflexes. Brain structures on MRI are also affected and there are differences in regions of the brain associated with the child’s genetic sex. Persistence of these findings suggest that they may be irreversible, but the jury is still out of this.
Finally, there is a parabolic association with pesticide exposure and Parkinson’s Disease. Mercury and lead exposure have also been associated with neurological diseases and the #1 toxin in the country, Arsenic, is associated with lung, bladder and kidney cancer, to list but a few. The thing about this that makes the information even more concerning is that there are currently over 80,000 chemicals currently used in the United States and less than 1% of these have been studied for safety prior to manufacturing. This is compounded by the fact that 2,000 new products come to the market every year, most of which haven’t had strenuous safety testing.
Figure 7 is my last graphic on this topic showing some common toxins and their associated diseases. Remember, there are over 80,000 of these currently in use in our country of which we know nothing about their safety.
After all of this, it would be easy to feel hopeless against the onslaught of all these chemicals and toxins. Yet we are all still here. Our body has been designed to cope with both natural-occurring toxins and all the new ones we are being exposed to on a daily basis. This by itself is an amazing feat, that our bodies can deal with tens of thousands of toxins that never existed prior to the 20th century. The issue is more that the levels of exposure are increasing to the point that our innate detoxification systems can no longer handle the excessive amounts of toxins and now these exposures are being associated with chronic diseases.
Our bodies neutralization and elimination of these toxins is called detoxification. In Part III, I will review how our body deals with all these substances and works to eliminate them from our bodies.
- Bouchard MF, et al. Prenatal Exposure to Organophosphate Pesticides and IQ in 7-Year OldChildren. Environ Health Perspect. 2011 Aug;119(8):1189-95.
- Rauh V, et al. 7-Year Neurodevelopmental Scores and Prenatal Exposure to Chlorpyrifos, a Common Agricultural Pesticide. Environ Health Perspect. 2011 Apr 21.
- Stout DM 2nd, American Healthy Homes Survey: a national study of residential pesticides measured from floor wipes. Environ Sci Technol. 2009 Jun 15;43(12):4294-300.
- Rauh VA, et al. Brain anomalies in children exposed prenatally to a common organophosphatepesticide. Proc Natl Acad Sci U S A. 2012 May 15;109(20):7871-6. doi: 10.1073/pnas.
- As of the writing of this there at 84,000 chemical being produced in the U.S.