The Link Between Toxic Exposures and Myeloma Risk

I have previously discussed ways to prevent myeloma (https://www.myeloma.org/blog/dr-duries/prevention-myeloma-within-reach).  A key step is to avoid toxic exposures. Although the Agency for Toxic Substances and Disease Registry (ATSDR), part of the U.S. Dept. of Health and Human Services, clearly identifies chemicals known to cause cancer (https://www.atsdr.cdc.gov/emes/public/docs/Chemicals,%20Cancer,%20and%20You%20FS.pdf), the Environmental Protection Agency (EPA) is currently rolling back many programs and rules (https://www.newyorker.com/magazine/2018/04/02/scott-pruitts-dirty-politics) to protect Americans. This is especially disturbing since the same chemicals that cause cancer, also cause brain damage in children (http://www.nejm.org/doi/pdf/10.1056/NEJMp1716809).

As with other aspects of myeloma care, knowledge is power. That is why it is so important to have a broad understanding of the toxic factors that can seriously impact health.

Linking Environmental Toxins to Increased Myeloma Risk

Several toxic chemicals are known to cause myeloma.  Multiple studies provide the “proof of principle” that chemicals are involved:

• The dioxins in Agent Orange, a powerful herbicide used by the U.S. military to destroy foliage and crops during the war in Vietnam, are well studied. A 2015 study (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5701511/pdf/nihms916029.pdf) linked the levels of the toxic chemical in the blood of exposed Vietnam veterans to the likelihood of developing myeloma.
• Another example is benzene (https://www.cancer.org/cancer/cancer-causes/benzene.html), one of the 20 most widely used chemicals in this country. Studies linking benzene to myeloma go back to 1897. Two recent meta-analyses, in 2015 (https://www.nature.com/articles/bjc2015108) and in 2011 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3040601), have confirmed the association of benzene exposure with the development of myeloma. The 1965 Bradford Hill criteria (https://en.wikipedia.org/wiki/Bradford_Hill_criteria), established by British scientist Sir Bradford Hill, are used to make the connection between benzene and myeloma. This approach has been endorsed by the Occupational Safety and Health Administration (OSHA), the National Toxicology Program (NTP), and the National Cancer Institute (NCI) President’s Panel in the U.S, and by the International Agency for Research on Cancer (IARC) in France. Other countries have researched and published data on the topic as well. The Occupational Diseases Medical Advisory Board in Germany published a study (https://link.springer.com/article/10.1007%2Fs00063-009-1032-8) showing a connection between benzene exposure and myeloma in 2009. South Korean studies appeared in 2014 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4085174/) and 2015 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4674490).
• Exposure to the herbicide glyphosate has been implicated in the development of myeloma in agriculture workers. Glyphosate is the primary ingredient in the popular weed killer Roundup, and is widely used in agriculture, especially on GMO (genetically modified organism) crops. Several years ago, a World Health Organization group, the International Agency for Research on Cancer, issued a controversial report (http://www.thelancet.com/journals/lanonc/article/PIIS1470-2045%2815%2970134-8/abstract) indicating that glyphosate “probably” causes cancer, a perspective supported recently by the state of California (http://www.cnn.com/2017/06/28/health/california-glyphosate-cancer-chemical-listing/index.html). 

Other causal factors

In addition to workplace exposures, other factors have been shown to be important. There are more than 100,000 chemicals in widespread use, with more than 1,000 new ones added annually. Unfortunately, regulations for these chemicals are weak to nonexistent. Exposures can occur in a variety of ways. For example, widespread pollution and toxic exposures (https://www.nytimes.com/interactive/2017/09/08/us/houston-hurricane-harvey-harzardous-chemicals.html) have occurred in the aftermath of hurricane Harvey in Houston, with particular concern about possible exposures to benzene. The New York Times reports (https://www.nytimes.com/interactive/2018/02/06/climate/flood-toxic-chemicals.html) that more than 2,500 sites in the U.S. handle toxic chemicals and are located in flood-prone areas. In addition, toxic exposures to benzene and POPs (persistent organic pollutants), which occurred during and after the events of 9/11, have been linked to the subsequent development of myeloma.

Dangers of processed foods

I have frequently emphasized the benefits of eating “real food.” (https://www.myeloma.org/blog/drduries/myeloma-patients-should-put-their-grocery-baskets-2018) In a new study from France (https://www.bmj.com/content/360/bmj.k322), “ultra-processed” foods are linked to an increased risk of cancer.  The culprits are industrially processed foods, including pastries, biscuits, juices, and processed fruits, vegetables, and meats. Risk factors for cancer include a high glycemic response linked to obesity, and the presence of specific contaminants, such as titanium dioxide, bisphenol A, and phthalates. Another study (https://www.sciencedirect.com/science/article/pii/S0160412017314666) recently linked cumulative phthalate exposures to dining out, which was shown to increase the levels of plastic-based chemicals (https://www.motherjones.com/environment/2018/03/the-science-about-eating-out-that-will-scare-you-into-cooking-your-own-dinners/) in the body.

And a new study (http://time.com/5200680/microplastic-water-bottle-orb-study/) reveals that microplastic contamination is found in most bottled water. We can add this to previous observations of micro and (https://www.iucn.org/news/secretariat/201702/invisible-plastic-particles-textiles-and-tyres-major-source-ocean-pollution-%E2%80%93-iucn-study)nanoplastics in food (https://www.iucn.org/news/secretariat/201702/invisible-plastic-particles-textiles-and-tyres-major-source-ocean-pollution-%E2%80%93-iucn-study), especially seafood.

The impact of these plastics is twofold:

• First, their presence disturbs the immune system, triggering T lymphocytes and activating macrophages, white blood cells that engulf and digest cellular debris and foreign substances.  In mouse models, Dr. Michael Potter (http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/potter-michael.pdf) showed that this type of activation triggers the development of myeloma. The highest likelihood of myeloma, he found, occurred with the injection of mineral oil containing pristane (a chemical known to be in diesel exhaust fumes) and tiny particles of plastic into the peritoneal cavities of mice. This is the most replicable model ever developed to lead to the production of myeloma.
• Second, plastics are contaminated with a variety of toxic chemicals, including fire retardants, dioxins, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs)—all of which are cancer-causing chemicals. Thus, there is a doubly serious concern.

Contaminated drinking water

As part of its responsibility to evaluate health hazards at specific superfund (toxic) sites, the Agency for Toxic Substances and Disease Registry (ATSDR) has assessed drinking water contamination at Camp Lejeune in North Carolina. The agency concluded (https://www.atsdr.cdc.gov/sites/lejeune/docs/atsdr_summary_of_the_evidence_for_causality_tce_pce_508.pdf) that the evidence linking benzene exposure to the development of myeloma was sufficient to allow the Department of Veterans Affairs to consider a presumptive service connection based upon causal evidence.

You are your own advocate

We can take personal responsibility for our health by avoiding chemicals that have been linked to cancer whenever possible. These include PCBs (polychlorinated biphenyls), pesticides, dioxins, chloroform, heavy metals, artificial sweeteners, artificial flavoring and coloring, benzoate (sodium benzoate), carrageenan, and partially hydrogenated oils. And keep in mind the recommendations made by ATSDR (https://www.atsdr.cdc.gov/emes/public/docs/Chemicals,%20Cancer,%20and%20You%20FS.pdf):

• Be aware of chemicals hidden in products you buy (https://www.atsdr.cdc.gov/emes/public/docs/Chemicals,%20Cancer,%20and%20You%20FS.pdf).
• Read product labels.
• Store chemicals safely.
• Use chemicals in well-ventilated rooms.
• Be aware of chemicals on the job: wear protective gear if needed/recommended (e.g. firefighters).

Be especially protective of your children. A new report identifies the risks of cellphone use (http://www.newsobserver.com/news/business/health-care/article207112454.html), especially for children. This study (https://www.nih.gov/news-events/news-releases/high-exposure-radiofrequency-radiation-linked-tumor-activity-male-rats) makes two important points. First, as with all types of exposure, causative exposures can occur early in life and have an especially dangerous impact at this developmental stage. Second, each type of exposure has a signature “fingerprint.” Cellphones can cause cancers not seen in other circumstances.

Likewise, the types of chemicals that cause myeloma are bone marrow toxins, which means they cause blood cancers like leukemia and lymphomas, in addition to myeloma. (Some of the myeloma mutations, such as t(4;14) and 17p-, are linked to specific toxin exposures and, as such, represent the signatures of that exposure.) Since the number of patients with leukemia and lymphomas are larger, the statistical correlations between toxins and those two diseases are often much stronger than in myeloma.

Bottom Line 

Toxic exposures cause myeloma. Regulations are not in place to protect U.S. citizens. Personal awareness and protection measures are essential to reduce or eliminate known risks. The enhancement of personal knowledge and advocacy on these fronts are among the IMF’s key goals moving forward. Stay tuned!

Dr. Brian G.M. Durie serves as Chairman of the International Myeloma Foundation and serves on its Scientific Advisory Board. Additionally, he is Chairman of the IMF's International Myeloma Working Group, a consortium of nearly 200 myeloma experts from around the world. Dr. Durie also leads the IMF’s Black Swan Research Initiative®.