David B. Wallinga, MD, MPA


November 30, 2010


Strong and ever-growing scientific evidence indicates myriad ways in which the environment influences both an individual's health and the health of the population as a whole. Clinical recognition is also increasing to show that environmental contaminants are significant contributors to disease, especially certain chronic diseases. Prominent successful public environmental health interventions have taken place, such as the US Environmental Protection Agency (EPA) policy which effectively phased out leaded gasoline in 1996, and many states acting to reduce exposure to secondhand smoke in restaurants, bars, and other public places since the 1990s. Today, 2 critical environmental issues with important health consequences remain largely unaddressed: the daily exposure of people to complex combinations of toxic chemicals, and the existence of an unhealthy and "obesogenic" food environment. Classroom medical education on these topics typically is limited or nonexistent. Clinicians can better help prevent the future diseases attendant on these problems if they more deliberately "green" their practices.

Primary Prevention and the Public's Health

The practice of medicine has long involved both personal and population health issues. When given to individuals, prevention advice typically involves abstention from harmful behaviors such as smoking, or regular scheduling of mammograms or other screening exams to head off disease in its early stages -- in other words, secondary prevention. At the population level, prevention more often takes the form of primary prevention -- promotion of health practices such as vaccination or sewage treatment to prevent disease before it occurs.

The usual examples of primary prevention offered in textbooks are vaccine campaigns and other public health actions against outbreaks of infectious disease. In part owing to the success of primary prevention, infections are no longer among the top 3 causes of death in the United States. That distinction now belongs to 3 chronic diseases: heart disease, cancer, and stroke. Certainly, individual behaviors, such as smoking, poor nutrition, and inadequate physical activity, play an important role in the development of these chronic diseases. Increasingly, however, these and other highly prevalent chronic diseases are being considered diseases of our industrialized, unhealthy environment. Two specific, albeit overlooked, problems are the toxic chemical environment and an obesity-causing food environment. Both today are of tremendous importance medically and in regard to public policy.

The Toxic Chemical Environment

For many clinicians, environmental lead has been the toxicity issue of greatest relevance. Identifying lead paint exposure, for instance, is usually the primary focus when an environmental history is taken. Burgeoning science is poised to change clinical practice with respect to human exposure to and toxicity from industrial chemicals, however.

We now know that Americans are regularly exposed to complex combinations of hundreds, if not thousands, of industrial chemicals well beyond just environmental lead. The Centers for Disease Control and Prevention's (CDC) Fourth National Report on human chemical exposure found hundreds of chemicals in urine and blood samples in individuals across the country.[1] Routine exposure occurs against a backdrop of approximately 82,000 EPA-registered industrial chemicals. Like bisphenol A (BPA), phthalates, lead, and other heavy metals, many chemicals are common ingredients in cosmetics, children's toys, building products, and even food packaging.

Federal safety regulations. Despite individuals' daily exposure to multiple chemicals, federal regulations are widely regarded as too lax to provide data on potential toxicity. Since 1976, industrial chemicals have fallen under the purview of the Toxic Substances Control Act (TSCA). At its passage, however, the 60,000 or so chemicals already in commerce were "grandfathered in" to the earlier, almost nonexistent safety standards. What that means is that for 99% of the industrial chemicals in use today, by volume, little or no toxicity or other data are available to suggest that human exposure to these chemicals is safe. Under the Act, manufacturers also have zero incentive to voluntarily produce these data. Despite -- rather than because of -- the weakness of federal laws, strong and ever-growing scientific evidence now links more than 200 diseases or conditions to environmental chemicals. The Collaborative on Health and the Environment maintains a public database tracking that evidence, ranking it as "weak," "good," or "strong," for more than 30 pesticides, industrial solvents, and other environmental chemicals. Some of these chemicals, including benzene (in gasoline), lindane (the active ingredient in lice shampoo), and the common yard pesticide 2,4-D, which were all rated as "good" or "strong," are now linked with greater risks of developing non-Hodgkin lymphoma.[2] In April 2010, the President's Cancer Panel of the National Cancer Institute released Reducing Environmental Cancer Risk: What We Can Do Now . The landmark report highlights the significant and underrecognized contribution of environmental chemicals to society's total cancer burden.[3]

Endocrine-disrupting chemicals. Heightened chronic disease concerns are not limited to cancer. In June 2010, the American Medical Association (AMA) issued a call for the federal government to reduce the public's exposure to endocrine-disrupting chemicals (EDCs) in the environment.[4] The AMA action arose from the Endocrine Society's collection of evidence that human exposure to such chemicals already is widespread, with strong concern that they "interfere with hormone biosynthesis, metabolism or action resulting in adverse developmental, reproductive, neurological and immune effects in both humans and wildlife."[5] These EDCs include pharmaceuticals (estrogen and diethylstilbestrol), pesticides (DDT, vinclozolin, atrazine), plastic monomers (BPA), plasticizer chemicals (phthalates), PCBs, dioxins, and many more.[5] A worthwhile 2010 report, The Health Case for Reforming the Toxic Substances Control Act , reviews the entire scientific literature in the context of toxic chemical regulation and policy.[6]

TSCA's lax testing requirements mean that we are unlikely to fully assess the safety of most of the 82,000 industrial chemicals in commerce anytime soon. TSCA also makes it extremely hard for the EPA to take an already-registered chemical off the market. Since the bill's passage in 1976, the EPA has succeeded in removing an already-registered chemical from the market only 5 times.

An Unhealthy Food Environment

Driving a significant proportion of the disease burden today are unhealthy diets, the obesity epidemic, and the chronic diseases closely related to them: heart disease, cancer, diabetes, and stroke. Efforts to blunt this epidemic have mostly failed. Many obesity experts who grapple with this dilemma now point to the need to change the modern "obesogenic" food environment, an environment that discourages physical activity and encourages consumption of calorie-dense, nutrient-poor food.[7,8]

Unhealthy food environments surround us. Policies in schools, hospitals, communities, and at the farm level all can contribute to less than healthy food environments. More focused efforts have long been under way to improve the food environment in schools, but many schools still offer meals that do not conform to federal guidelines for healthy eating. Sodas and other junk foods are allowed to be marketed to children via vending machines or at kiosks in schools, competing with healthier offerings for students' attention. Many hospitals host fast-food franchises on their campuses or offer burger-and-fries "value meals" in their own cafeterias, while upstairs they treat the diseases to which these diets contribute.

In the March 2010 issue of Health Affairs, a commentary made the case that a federal "cheap food" policy instituted in 1974 has spurred farm production of a few commodity crops, such as corn and soybeans, but not fruit or vegetables.[9] Consumption of excess calories in the form of inexpensive, nutrient-poor snacks, sweets, and sweetened beverages made with the fats and sugars derived from these same policy-supported crops is a key driver of the child obesity epidemic.[9]

Many good policy options exist at the local, state, and federal levels for improving unhealthy food environments. Yet these environments persist, often due to inertia, because financial interests are vested in keeping them that way or because of a lack of community leaders who are willing to push for improvements.

Greening Your Practice

The peer-reviewed scientific literature has created a new understanding about how both the toxic chemical environment and an obesogenic food environment are helping to drive the rate of cancer, obesity, and related chronic diseases seen in many of our patients.

Unfortunately, medical education has not kept pace. Most clinicians still receive very little instruction on how to look at wellness and disease through an environmental lens and how to modify their practices accordingly. This environmental lens is much more than a quirky perspective, however; it is quickly becoming a necessity for clinicians to better understand and address some of the most important drivers behind the health of their patients. "Greening" your practice can be a kick-start to ensuring that your approaches and advice to individual patients are evidence-based in current science.

Green the patient history. First, consider greening your patient's history and physical. Make it part of your routine to take an environmental history. Ask not only about workplace exposures to chemicals, but also about the kind of products your patients use. In regard to food, find out about what is in the household food environment -- the pantry and fridge -- and what portion of the household food budget goes towards sugared drinks and eating out. Are parents aware of the availability of processed and junk foods in their children's schools? They should be, and so should you.

Green advice. Second, green your advice to patients. Start by advising patients to avoid exposure to environmental chemicals by changing their decisions about what kinds of household products to buy and use. This advice is consistent with findings and recommendations from the President's Cancer Panel and from the Endocrine Society with respect to environmental carcinogens and EDCs. A growing number of patient handouts and other materials also have been prepared for busy clinicians wanting to build environmental advice into their practices. These include the Pediatric Environmental Health Toolkit, endorsed by the American Academy of Pediatrics and developed by Physicians for Social Responsibility.[10] CME credits can be earned for learning about the toolkit as well. The University of California, San Francisco, Program on Reproductive Health and the Environment is preparing similar curricula and practice material for reproductive health professionals, including its "Toxic Matters" brochure for patients.[11]

In regard to advice on food choices and safety, the Institute for Agriculture and Trade Policy offers a series of science-referenced Smart Guides (Smart Produce Guide, Smart Plastics Guide, Smart Guide to Food Dyes, Smart Guide to Hormones in the Food System) that educate patients and consumers on how to make informed decisions when buying food -- including awareness of food packaging -- so as to reduce exposure to toxic chemicals.

Be a model. Third, make your practice location itself a model for a healthier community environment. Not that long ago, as much as 10% of mercury emitted from waste incinerators came from the healthcare sector. By shifting away from waste incineration and by preferentially buying medical products without mercury, hospitals and clinics have been able to reverse this trend. Practitioners can further green their practices by choosing medical or office products containing less packaging and fewer toxic chemicals, and by asking that their clinics, hospitals, and health systems do the same.

Healthcare institutions that want to work towards environmentally conscious and sustainable practices can consult Practice Greenhealth. Practice Greenhealth is a membership and networking organization that offers information (Webinars, CE credits, etc.) on and compiles the best practices for greening healthcare facilities, including work in green design and construction; facilities management; environmental purchasing; clean energy purchasing; waste management; and greener, healthier management of pests and chemicals.

For the last 6 years, Health Care Without Harm, a coalition of more than 450 members in 52 countries, has worked to make the food offered within its hospital and clinical practice environments healthier. More than 250 hospitals have now signed a healthy food pledge to buy food that is not only nutritious but also produced in ways that are ecologically sound and socially responsible. One pledge signer, Fletcher Allen Medical Center in Burlington, Vermont, buys only chicken produced without arsenic or antibiotics routinely added to feed. It also purchases food from local suppliers and serves only species of fish that are sustainably harvested and lower in mercury. To pledge your clinic or hospital on the road to healthier food, or to find case studies of various facilities that have put this goal into practice, visit the Health Care Without Harm Website.

Be an advocate. Clinicians may reasonably conclude that toxic environments that have been decades in the making are unlikely to change solely through voluntary action or through the marketplace. With respect to tobacco use, the greatest public health improvements occurred only after laws or policies were enacted to change the environment, making tobacco use less convenient. These policy changes were fought hard by the companies that had financial stakes in seeing this action delayed. Physicians and other health professionals became advocates for tobacco use policy changes in their communities. Some likely saw their public health advocacy as a logical extension of the Hippocratic Oath and their practice.

Perhaps health professionals should approach advocacy for policies to make their communities' chemical and food environments healthier as just another part of the greening of their practices. Already, in many states and at the federal level, health professionals and/or their organizations are engaged in trying to reform the regulation of toxic chemicals. Safer Chemicals, Healthy Families is a coalition of nursing, public health, learning disability, reproductive health, and other organizations that are working to pass legislation; it would represent the first major overhaul of TSCA since 1976. Member organizations include the American Nurses Association, the Breast Cancer Fund, Physicians for Social Responsibility, Health Care Without Harm, and the Environmental Health Group of the Yale School of Medicine.

First Lady Michelle Obama's Let's Move campaign, launched in February 2010, has made the realization of healthier food environments in schools and communities a pillar. The campaign calls upon community leaders, including clinicians, to become active in the campaign by advocating for healthier schools, starting community gardens, or promoting community access to more affordable, healthy foods. Let's Move indicates on its Website that the American Academy of Pediatrics will soon ensure that clinicians across the country provide patients with advice on healthier eating and write parents prescriptions "laying out the simple things they can do to increase healthy eating and active play."

Another opportunity for advocacy is involvement with Healthy Food Action, an organization that serves as a vehicle for busy healthcare professionals, including clinicians, to lend their voices to the important debates of the day pertaining to food and farming policy at the federal level. The coming 2012 Farm Bill, which could easily comprise $60 billion in spending per year, is one such opportunity. The decisions made in writing the Farm Bill will shape what foods the nation's farmers grow and indirectly the availability and relative price of foods. For that reason alone, it could easily be called the nation's Food and Farm Bill.


Many chronic diseases and conditions that are prevalent or rising in prevalence are linked by scientific evidence to unhealthy chemical and food environments. Not only does this increase patient harm, it also contributes to runaway healthcare costs. Clinicians may feel ill-prepared to address these environmental contributors to disease; most did not have classes in medical school that were specifically focused on environmental or nutritional health. Many practices also offer few tools or incentives for clinicians to build more environmental advice into their patient visits. An increasing number of resources are now available for clinicians looking to green their practices, whether the practice is defined solely as what takes place in patient rooms or whether it also includes the broader clinic or hospital environment or even the surrounding community. Because chemical and food environments are inherently community issues, clinicians may find advocacy for healthier chemical and food policies to be an essential component for reducing the unhealthy food and chemical exposures already affecting their patients.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: