Mounting evidence is linking industrial chemicals to conditions ranging from reproductive disorders such as subfertility, infertility, low birth weight, gestational diabetes, and birth defects,1-3 to neurodevelopmental disorders such as attention deficit disorder and autism, to chronic diseases including obesity, diabetes, heart disease, and cancer. Additionally, environmental chemicals can have epigenetic effects, leading to potential transgenerational health consequences. 3,4
A subset of common industrial chemicals has been shown to act as endocrine disruptors, namely select pharmaceuticals, polychlorinated biphenyls, plasticizers (eg, bisphenol A [BPA]), and a variety of pesticides.
Physicians are not typically taught about the impact of environmental toxin exposure during their medical training. Only one in 15 obstetricians/gynecologists, for example, reported any training on the topic when queried.6 Yet, less than 20% of these specialists routinely asked their pregnant patients about any environmental exposure whereas all of them reported asking about other lifestyle factors such as alcohol and tobacco use, and diet.6
Pediatricians were generally more proactive. A national network of 12 pediatric environmental health specialty units (PEHSUs) was created by the United States Agency for Toxic Substances and Disease Registry in 1998. But a 2010 survey of Michigan pediatricians indicated that they are not widely utilized.7 These pediatricians indicated a lack of confidence in their ability to manage exposures to pesticides, air pollution, mercury, mold, and polychlorinated biphenyl.
A literature search revealed no access to training on environmental toxins for endocrinologists; nor are endocrine-disrupting chemicals (EDCs) mentioned in the Accreditation Council for Graduate Medical Education program requirements for endocrinology, diabetes, and metabolism.
In a position statement published by the Endocrine Society,8 the prevailing evidence and risks were presented. the authors advised endocrinologists to become knowledgeable about common sources of endotoxins and increase their awareness regarding the clinical implications of environmental exposures in utero and throughout life.8 The report also strongly advocated for practitioners to make the information available to the public.
Finally, the Endocrine Society advocates that the precautionary principle is relied on to help prevent exposures. A follow-up report, published in 2015,9 pointed to seven broad areas in which the evidence for adverse effects is strongest: 1) obesity and diabetes; 2) female reproduction; 3) male reproduction; 4) hormone-sensitive cancers in females; 5) prostate cancer; 6) thyroid diseases; and 7) neurodevelopment and neuroendocrine system disorders.
There are 4 overarching recommendations that clinicians are encouraged to adopt:9
In addition, endocrinologists are advised to consider the following:
It can be quite challenging, absent an industrial accident, to discern what if any environmental toxins a patient may be exposed to. Ask your patients to take on the role of detective in exploring various possibilities as you present possible situations of possible exposure.
While health practitioners and patients alike may feel overwhelmed by the vastness of potential exposures, practical steps can greatly reduce a person’s chemical burden. For instance, food and water are key sources of exposure since they carry pesticides, herbicides, and insecticides, which can be selectively avoided.
These potential sources of chemical toxins can be mitigated by referring to the Environmental Working Group (EWG) list of the Dirty Dozen (most contaminated produce) and the Clean 15 (least contaminated produce).10 When foods are chosen from the Clean 15, the EWG estimated that people may avoid 93% of the environmental toxin exposure they would have experienced had they been regularly consuming foods from the Dirty Dozen.
Another common source of endotoxins arises from fish that contain a high mercury content among other problematic chemicals. Advising patients to select from among the preferred list of fish with the least mercury content, polychlorinated biphenyls (PCBs), and other environmental toxins are recommended. A healthier choice list of fish can be accessed from resources prepared by the University of Arizona Center for Integrative Medicine.11 In particular, women should be warned to limit canned tuna intake to chunk lite, which contains the lowest level of mercury, and to consume it or feed it to young children no more than once weekly.
The lining of canned foods has typically contained BPA, and therefore canned foods are best avoided, especially when the food item is available frozen. Fortunately, companies that are now packaging foods in BPA-free cans.12
For those who can afford it, and especially for pregnant women and children, in addition to organic produce, recommending that patients select organic foods such as dairy and meats is desirable. Similarly, advocating that parents substitute children’s usual food choices with identical organic products can significantly reduce detection of an organophosphate metabolite in their urine.12 However, when food dollars are limited, prioritizing meat and poultry is advisable since these dietary options are “higher up” on the food chain, so they will bioaccumulate more environmental chemicals in their flesh than either dairy or produce.
Other simple educational precautions that clinicians might share with patients:
While living life entails risk, our goal is not to overwhelm or cause patients undue worry. However, initiating a discussion is warranted with every patient. After raising this topic, typically I will provide a list of resources to my patients, and then remind them “the perfect is the enemy of the good.” I have found it helpful to encourage them to take the easiest steps to reducing their exposures first and then gradually make additional changes when feasible.