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Linking Illness to Chemical Exposure

My wife of over 50 years suffered from Alzheimer’s disease. Were toxic chemicals used on the family farm a possible causative factor? We will never know. The linking of illness to chemical exposure is extremely complex as the following article explains.

On March 18, 2021 – we (friends and family) lost a beautiful soul to Alzheimer’s disease. After my wife Margrit’s diagnosis in 2014, we struggled to accept the inexorable loss of her most precious assets that defined who she was. Of course, we also asked why. How could this happen? The assumption – genetics was the main factor. Afterall, her mother died of Alzheimer’s in 1987 and her youngest brother is now in a care home for the same illness.

But then – there are indications that genetics may be only part of the story. There have been no recorded cases of dementia among Margrit’s many Swiss relatives. Moreover, it is early onset dementia, that is typically linked to genetic factors. So the question arises – could exposure to chemicals used on the family farm be a factor? Margrit and her siblings would describe the arial spraying of their crops with pesticides (including DDT in the early 50s) and even running behind the low flying planes! They grew mushrooms which could have exposed them to a variety of chemicals as well as mushroom spores which have been associated with illness, most notably lung inflammation. Their water supply was a shallow well that could have been contaminated with some of the farming chemicals. It’s a legitimate question to pose. Evidence from recent studies shows a possible association between chronic pesticide exposure and an increased prevalence of dementia, including Alzheimer’s disease (AD) dementia.

THE CONCLUSION? We will never know the full answer. The linking of illness to chemical exposure is incredibly complex, even in the most extreme cases in which the exposure has been properly measured and the illnesses well documented. Consider 3 examples that demonstrate these challenges – especially when cases go to the courts for which the proof must be beyond a reasonable doubt. 

Linking Illness to Chemical Exposure

Smoking – In the early 1950s, the tobacco industry had sufficient evidence that smoking could be associated with cancer. By the 1970s there were scores of lawsuits associated with illnesses from smoking, but the tobacco industry was generally successful at defending itself mainly because the cancer link was not unequivocal. Industry could claim that other factors such as genetics, lifestyle, and exposure to other toxins, could have been factors. It was not until the late 1990s that the tobacco industry was held accountable and faced massive financial settlements.

Chromium – Hinkley, California is a small town in San Bernardino in southern California. In 1952, the Pacific Gas and Electric Company (PG&E) installed a compressor station near the town as part of a gas pipeline system linking Texas to California. Chromium (hexavalent chromium) was used as a corrosion inhibitor in its cooling system. The contaminated water was discharged into unlined pools, thus leaking into the aquifer serving Hinkley’s residents water needs.

Daily Dose of Chemical Exposure

Julia Roberts in the movie Erin Brockovich

The residents of Hinkley experienced a wide range of illnesses – asthma, nosebleeds, miscarriages, and several cancers. Medical research at that time did indeed demonstrate that Hexavalent Chromium could be associated with many of those illnesses. Erin Brockovich, a clerk at a local law firm, was instrumental in initiating legal action against PG&E in 1993. The case was featured in a blockbuster movie starring Julia Roberts as the law clerk Erin Brockovich.

In defending PG&E, lawyers tried to de-link people’s health problems from exposure to chromium. They likely would have been successful except for the fact that the plaintiffs had evidence that the company knew about the water contamination since 1965 but did nothing about it. PG&E eventually managed to take the case out of courts and reach a settlement through mediation, paying the plaintiffs a total of 333 million dollars, one of the largest settlements of that nature, in US history.

Teflon Manufacture – From 1951 to 2013, Teflon was produced by Dupont’s plant in Parkersburg, West Virginia. The manufacturing process used Perfluorooctanoic acid, (or PFOA or C-8) – one of many of a class of fluorinated hydrocarbons now known as forever chemicals due to their long-term stability. In 1998 multiple lawsuits were filed against Dupont.  Local farmers, residents and company workers claimed to have suffered illnesses and livestock mortalities linked to pollution from DuPont’s Parkersburg plant. DuPont was forced to provide millions of dollars for medical monitoring of over 70,000 people.

In 2012, a science panel concluded (from these studies) a “probable link” existed between C8 and six diseases: kidney cancer, testicular cancer, ulcerative colitis, thyroid disease, pregnancy-induced hypertension and high cholesterol. Since then, there were numerous individual lawsuits from victims of PFOA-related diseases. In February 2017, DuPont settled over 3,550 lawsuits for 671 million dollars.


environment matters

A pattern emerges – The above examples exemplify the challenges in linking illness from exposure to chemicals – even in the most egregious of cases. The 3 points that become clear are –

  • Evidence denialism – The industries that should have been responsible had access to credible knowledge concerning the health impacts of exposures but resorted to tactics to suppress such knowledge.
  • Decades to prove – It took decades to eventually reach the point to when the offending industries were held financially accountable.
  • Delinking – In court proceedings, the industries were initially able to argue cases de-linking the people’s health problems from exposure to chemicals. However, the court cases eventually succeeded in large part because of the proven cover-ups and delays.

Fortunately, there are some notable examples in which compensation is provided on the presumption of a link. A very important example — Firefighters die of cancer at significantly higher rates than the public. One of the largest studies involved examining nearly 30,000 urban U.S. firefighters over a span of almost 60 years. The study confirmed that firefighters have a nine per cent higher chance of developing cancer at some point during their lives, and a 14 per cent higher probability of subsequently dying from cancer than the general population. In most jurisdictions – firefighters are properly compensated and rightly so. For example – in British Columba if a firefighter develops one of the listed cancers after a certain period of employment, it is presumed that the cancer arose from their employment. The firefighter is then eligible for workers’ compensation benefits without having to prove the cancer is work-related. 

Daily Dose of Chemical Exposure

So – where does this leave the general population? As presented in the previous blog, many dangerous chemicals can be closer to home than we think. Man-made chemicals are everywhere: in water and dust, food packaging, personal hygiene products and household cleaners, furniture and electronics. Recently (this May 2022), an international group of scientists analyzed more than 1,200 scientific studies where chemicals had been measured in food packaging, processing equipment, tableware and reusable food containers.

This is clearly wrong. These chemicals are introduced without sufficient study and their use is often not even justified as has been recently exposed in the case of widespread use of fire retardants in furniture and carpets. The chemical industry must be much more effectively regulated. There are ongoing legislative initiatives in this direction but industry, through various channels (think tanks, associations, etc.) are unrelentingly directing massive financial investments towards lobbying and financing the campaigns of sympathetic political candidates. It is frustrating to observe. We can only hope that evidence-based decision making will eventually prevail.


As a respite from this rather gloomy picture, the final article in this series on toxins – coming soon — will outline ways in which we can minimize toxic exposure in our everyday lives.