Should doctors care about environmental health while treating patients?

For the majority of my graduate and postgraduate training, I have studied the pulmonary and cardiovascular effects of air pollution. Through this time, I can recognize that my mindset and understanding of the importance of air pollution in public health continues to shift. In many ways, I would like to think that as I spend more time in this field, I gain greater distance from the minute details, allowing me to put the complex research into a cohesive story that gives me freedom to see this type of public health problem with perspective. As I have written in my previous post, it is challenging to distinguish between environmental exposures that are truly hazardous from those that are mostly hype, and I am still grappling with placing certain highly talked about environmental exposures in one category or another, but air pollution is not confusing for me. In my perspective, fine particulate air pollution (aerosolized particles with a diameter less than 2.5 um, PM_2.5) is truly hazardous, and it has serious public health implications on a population level. I am not alone on this either, in the most recent Global Burdens of Disease report published in Lancet, ambient fine particulate air pollution was found to be the #9 cause of disease worldwide, reaching as high as the #4 cause of disease in East Asia. Even worse, household air pollution, resulting from the practice of combusting solid fuels indoor for cooking, is believed to be the #4 cause of disease worldwide, reaching as high as the #1 cause of disease in South Asia. Household air pollution doesn’t make the list in North America, Western Europe, or Australia, as this cooking practice is generally rare in these areas. Even worse still, tobacco smoking and second hand smoke, is the #2 cause of disease worldwide. Although tobacco smoking isn’t quite the same as ambient or household air pollution, there are many similarities.

http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)61766-8/abstract

My belief in the importance of air pollution in public health continues to shift due to my own research, where I am becoming exceedingly convinced that in utero and early life exposure to air pollution will have life long effects on susceptibility to cardiovascular disease. As we publish on this, I will write about this more, and my hope is that these observations will be translated to epidemiological studies to investigate if these effects are observed in human populations. In any event, the actual effect of air pollution on disease may very likely be much greater than what we currently know.

But, looking at the top 10 on this list, it is almost amazing to realize that nearly all of these seem to be modifiable factors. Let’s look at the top 10:

1) high blood pressure

2) tobacco smoke

3) alcohol use

4) household air pollution

5) diet low in fruits

6) high BMI

7) high fasting glucose

8) childhood underweight

9) ambient particulate matter

10) physical inactivity

Now, I recognize that there are always going to be many outside factors that influence these risks, and not all of them are easily modified. In the U.S., socioeconomic status, education level, access to fruits and vegetables, access to safe places to exercise, etc., all of these will influence factors such as diet, alcohol use, and physical activity, which will have major impacts on health. But when I look at this list, I ask myself, how does the physician address each one of these?

When looking at the #1 cause of disease, high blood pressure, I know that the physician will treat this in many ways. The physician may utilize behavior modification strategies to try and change diet and activity, encouraging weight loss and lower sodium intake, but also the physician will likely use one of several good pharmacological options to try and drop BP. Looking at tobacco smoke, nearly every physician will counsel their patient on tobacco smoke, they may even be required to counsel their patient on this depending on where they practice. Perhaps the doctor will pull out the 5A’s and 5R’s of tobacco cessation (Ask, Advise, Assess, Assist, and Arrange, Relevance, Risk, Rewards, Roadblocks, Repetition (http://www.primaris.org/sites/default/files/resources/Smoking%20Cessation/sc_algorithm.pdf), and there seems to be evidence that it works (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2628990/). The same trend goes with alcohol consumption, diet low in fruits, high BMI, high fasting glucose, and physical inactivity, the clinician has a plan for each one of these… except for air pollution.

Two years ago, a very reputable cardiologist and environmental health researcher from the US EPA and University of North Carolina came to the UW to give several talks and to meet with our group investigating traffic related air pollution and cardiovascular disease. With his visit, he gave the early morning Cardiology Grand Rounds talk at UW, where he met the weary eyes of the residents, fellows, and attendings, looking for CME credit before they start their day in their clinics or hospital units. He gave what was in my opinion, a fascinating talk that highlighted the truly exciting work coming out of the US EPA on air pollution and cardiovascular disease. Looking around the room, I mostly saw physicians sleeping, but a few people seemed to be engaged. After his talk, I was standing around, talking with some colleagues, when one of the highly influential cardiology attendings at UW proceeded to explain to us PhD dimwits, “there is simply no place for air pollution in the cardiology clinics!” At first, I was taken aback by what I thought was a short sighted view of the role of air pollution in population level cardiovascular mortality, but with letting his comments sit for a while, I asked myself, “Is he right? Is there no place for air pollution to be discussed in the clinic?”

Not too long after this encounter, I was invited by a group of physicians in Whatcom County to give my own CME Grand Rounds seminar at St. Joseph Medical Center in Bellingham, WA, on the health effects of fine particulate air pollution. When preparing for this seminar, I was asked to produce a document that would explain what the clinicians would gain from attending my seminar, and specifically, how it would influence their practice of medicine. In trying to answer this question, I had to do a little exploring.

The reality is that air pollution is a major contributor to disease, but the answer to reduce the adverse effects of this type of exposure is simple yet complex: eliminate exposure. Although the concept is simple, unfortunately, reducing exposure isn’t easy. This is why strong air quality policies are critical in playing this role. So what can the physician do? Well, the EPA has some very simple guidelines for clinicians, 1) teach your patients about the air quality index, find it at http://airnow.gov/, and teach them to use it, and 2) if air quality gets bad, make certain recommendations such as, reduce prolonged heavy exertion when air pollution is moderate, to completely avoid physical activity outside when air pollution is truly bad, here are the recommendations http://www.airnow.gov/index.cfm?action=pubs.aqguidepart.

When answering the question of how my seminar will add to doctors' clinical practices, I reluctantly put the EPA guidelines down, but there’s more to it than that, and I wasn’t satisfied with these simple guidelines being the only way clinicians would use air pollution in their clinics.

I find these recommendations to be sound, solid recommendations. They are pretty simple, potentially easy to follow, but will following these guidelines really make a big difference? In a region such as the PNW, bad air pollution events only happen once or twice a year, and perhaps there would be some modest benefit to advise patients who are living with current heart or lung diseases to avoid physical activity outside during this time, but the overall benefit is likely to be quite small. So, other than simple recommendations for those with chronic lung and heart diseases, can the physician play a role in trying to bring air pollution down on the list of causes of disease?

After trying to understand the role for the clinician in environmental health, I have come to believe that the physician has an extremely important role to play in reducing risk of disease from environmental exposures, although my reasoning may be somewhat convoluted, stick with me. As I mentioned above, in nearly every environmental exposure, the way to reduce an adverse effect of exposure on disease risk is to eliminate exposure. Certain environmental exposures can be modified by the individual (take smoking for example, or exposure to consumer products, or heavy metals in fish), but more often than not, environmental exposures occur without permission, where someone passively inhales the fine particulate that emerged from a diesel engine, and subsequently suffers from increased risk of disease. With looking at air pollution, exposure can be looked at as the product of concentration and time (C x T), the physician can advise patients to avoid outdoors and prolonged exercise in bad air pollution events (decreasing T), but if C doesn’t change, it’s going to be tough to truly drop exposure over the long run. This is why I am an avid proponent of a strong regulatory body such as the US EPA, setting regulatory standards that protect those who would suffer the health impacts from the hands of development without any of the financial profit. But what can the physician do in setting regulatory standards?

The reality is that when a patient has questions about health and the environment, they ask their doctor. There is an excellent 2003 review article in Pediatrics, titled “Environmental Risk Communication for the Clinician”, for those who are clinical doctors, I recommend it. When I read this, there were 3 important concepts that stuck with me, 1) clinicians are the #1 trusted and credible source of information on environmental health risks, 2) questions about environmental health rank among the top in questions patients have for their clinicians, yet clinicians have a hard time answering them, and 3) overall, most people go to their doctors. Meaning that when people have questions about environmental health risks, they’re more than likely to ask their doctor.

http://pediatrics.aappublications.org/content/112/Supplement_1/211.full.pdf

So what does this mean for regulatory policy? How will the information the doctor knows about environmental health influence any US EPA standard and reduce exposures? The answer is that our regulatory policies change when the public demands change. As much as we would like to believe that our regulatory standards are set with a perfect communication between environmental health researchers and EPA policy makers (who are obligated by law to set standards without the influence of politics or economics), the public has historically played a critical role to influence policy by demanding change.

Below is an image of the air pollutants sulfur and nitrogen oxides in the Eastern Half of the U.S., comparing the differences in concentration between 1989 and 2004 (From Casarett and Doull’s Toxicology). What is obvious is that air pollution has dramatically improved since reaching its worst in the 60s, 70s, and 80s. The reason it has improved is due to the Clean Air Act and subsequent additions to the law, increasing its regulatory strength. Prior to the CAA, the public was fed up with the poor air quality, and vigorously advocated for change. Even today, nearly everyone I have met who lived in Southern California in those decades remember how bad it was and have their own personalized stories of eyes and lungs burning. The public’s advocacy is what led to this major policy, reducing exposures of air pollution for millions of Americans and improving the health of the public.

http://books.google.com/books/about/Casarett_Doull_s_Toxicology_The_Basic_Sc.html?id=4yi7-j48uhIC, Casarett and Doull’s Toxicology, page 1123

Today, our health hazards from environmental exposures are less obvious. With particulate air pollution, people may not even notice when air quality is truly bad, yet the human health risks are still there. My belief is that physicians, whether they like it or not, have a role to play in educating the public when it comes to environmental exposures. When the public is educated about real and potential health risks from environmental exposures, public advocacy demanding regulatory changes will follow. Although I recognize that with 15 min clinic visits, bringing up environmental health isn’t necessarily at the top of the list (and it shouldn’t be), I do believe that physicians need to have a strong understanding of these risks to better counsel patients when they have questions, or when exposures do become a serious clinical concern.

I would be very interested to hear from any clinicians about their experiences with counseling patients on environmental exposures, is it something that ever comes up in your clinics? Do you have any advice on how to answer these questions?

Thinking back to the influential attending who didn't t believe air pollution had a role in the cardiology clinic; in my view, air pollution is a major cause of cardiovascular disease, and if the goal in medicine is to improve health and ease suffering, air pollution and other environmental factors will be a part of the equation until the exposures are zero, until then, I believe it will always have a place in the clinic.

Chad Weldy