Future CV Shock: The Impact of Climate Change, Pollution and War on Medicine
Cover Story | When one thinks about the future of cardiovascular medicine, the mind may wander in different directions. For some, the path is new drugs, enhanced imaging, and even novel ways of testing new therapies, all coalescing to improve patient outcomes.
For others, the thought process flows another way and the future is less cheery: increasing pollution will have adverse effects on cardiovascular health, global warming will cause new problems as well as a resurgence of old health problems, and increasing numbers of people and countries will be torn apart by conflict, hardly able to access any medical care much less cardiovascular care. The planning committee for the 2015 American College of Cardiology (ACC) Scientific Sessions, as part of a new 13-session track devoted to the future of cardiovascular medicine, traveled this darker road and came up with a decidedly apocalyptic list of near-future woes affecting global cardiovascular health: climate change, pollution, and whole countries ripped asunder by war.
The session was designed to promote greater awareness that having to wait for an MRI for your patient may not be the worst thing to ruin a workday.
“There is a lot going on around us, outside our normal cardiovascular science, that affects the cardiovascular health of our nation and our world,” said Ralph G. Brindis, MD, MPH, from the University of California, San Francisco, who led the session entitled: Beyond Medicine - Impact of Climate Change, Pollution, Population Migration, War: Future of Cardiovascular Medicine XIII.
In an ACCEL interview, session panelist William A. Zoghbi, MD, from Methodist Debakey Heart Center and Houston Methodist Hospital (Texas), added, “The topic is unusual and I’m glad the ACC chose to highlight it because I think there are some developments here…Let’s think globally a bit.”
“As cardiologists, we are going to be looking well beyond blood pressure and cholesterol as we look at the way the world around us is changing, and certainly when you add to that the trauma and the problems we’re seeing with current conflicts around the world, there is more than enough for those of us that are interested in international work,” noted panelist Sidney C. Smith, Jr., MD, from the University of North Carolina, Chapel Hill.
Add in Salim Yusuf, MD, DPhil, from McMaster University, Hamilton, Ontario, Canada, and the session panel was a veritable who’s who of CV medicine leadership.
So what do these experts say lies ahead around the globe?
Warming Up to Climate Change
Whether due to natural forces or the influence of human activities, climate change is happening. A report from the U.S. National Institute of Environmental Health Sciences (NIEHS) notes that the environmental consequences of climate change, including those already observed and those anticipated—such as sea-level rise, changes in precipitation resulting in flooding and drought, heat waves, more intense hurricanes and storms, and degraded air quality—will affect human health both directly and indirectly.1
Some confusion reigns in regard to the difference between climate change and weather patterns. The latter describe short-term events, while climate change is a longer process that affects the weather. Record-breaking cold and heavy rain and snow conditions, such have been experienced in the last several years in much of North America, are actually consistent with global warming as an overall warmer planet changes weather patterns throughout the year everywhere.
Several cardiovascular diseases (CVD) show climate sensitivities, with both extreme cold and extreme heat directly affecting the incidence of hospital admission for chest pain, acute coronary syndrome, stroke, and variations in cardiac dysrhythmias. Such weather conditions serve as stressors in individuals with pre-existing CVD and can directly precipitate exacerbations. For example, the stress of specific events, and anxiety over event recurrence, are associated with myocardial infarction, sudden cardiac death, and the development of stress-related cardiomyopathy.
Climate itself also stands as an indirect risk for CVD: the incidence of certain vector-borne and zoonotic diseases impacts cardiovascular manifestations. Some occur predominantly outside the U.S., such as Chagas disease, which is an important cause of stroke and heart failure in Latin America (but not in the United States). On the other hand, Lyme disease is a prevalent vector-borne disease in the U.S. that has cardiovascular manifestations.
While there is little published literature projecting direct and indirect impact of climate change on CVD incidence, the NIEHS notes that insofar as climate change will bring increased ambient temperatures, increasingly variable weather, and increased extreme events, “we can infer that climate change will likely have an overall adverse impact on the incidence of cardiovascular disease.”1
Air Pollution: A Breath of Not-so-fresh Air
Numerous studies have linked exposure to fine particle pollution to a variety of health problems including increased respiratory symptoms (irritation of the airways, coughing, difficulty breathing), decreased lung function, aggravated asthma, development of chronic bronchitis, arrhythmias, nonfatal heart attacks, and premature death in people with heart or lung disease.
A 2010 American Heart Association (AHA) Scientific Statement on the topic concluded that particulate matter (PM) is a “causal factor” in both the development of atherosclerosis and the triggering of CVD-related mortality and nonfatal events.2
“It comes in many different packages, whether it’s a coal refinery north of Beijing or an indoor stove in India. This is a contributor to the development of atherosclerotic vascular disease,” said said Sidney C. Smith Jr., MD, one of the authors of the 2010 AHA statement.
Importantly, the AHA statement also said that “reductions in PM levels are associated with decreases in cardiovascular mortality within a time frame as short as a few years.” Dr. Smith noted that there have been successful efforts to reduce exposure to second hand smoke, with attendant successes in reducing events. Recently, Newman and colleagues reported for the first time that fine particulate air pollution is also independently associated with carotid artery stenosis, an important risk factor for cerebrovascular disease and stroke.3
WHO: Pollution Produces 7 Million Premature Deaths
In 2014, the World Health Organization (WHO) released new estimates that suggested that in 2012 around 7 million people died—one in eight of total global deaths—as a result of air pollution exposure.4 This figure was more than double previous estimates, confirming that air pollution is now a leading environmental health risk.
What was particularly surprising about the data: a much stronger link emerged between both indoor and outdoor air pollution exposure and cardiovascular diseases, including stroke. Indeed, the WHO stated that about 40% of outdoor air pollution-related deaths were attributable to ischemic heart disease, and another 40% to stroke. As for indoor pollution-caused deaths, 34% were from stroke and 26% from ischemic heart disease. For comparison, lung cancer accounted for only 6% of deaths.
“The risks from air pollution are now far greater than previously thought or understood, particularly for heart disease and strokes,” said Maria Neira, MD, Director of the Department for Public Health and Environment at the WHO, in a press release.4
William Zogbhi, MD, called the data “startling” and issued an appeal to “think globally but act regionally,” particularly as any reduction in air pollution will have multiple effects in terms of reducing CVD, cancers, and respiratory diseases.
“Laws that would decrease pollution—in whatever shape or form—will affect so many people at the same time. It’s almost like an effect en masse,” he said.
The new estimates are not only based on more knowledge about the diseases caused by air pollution, but also upon better assessment of human exposure to air pollutants through the use of improved measurements and technology. This has enabled scientists to make a more detailed analysis of health risks from a wider demographic spread that now includes rural as well as urban areas.
“Disease prevalence is much higher in Southeast Asia and the Western Pacific areas, where the indoor pollution is primarily from cooking and heating the home using coal, wood burning, and other sources that produce fumes,” said Dr. Zoghbi. “Outdoor pollution is your usual pollution because of energy production, waste management, and the like.”
Climate change also contributes to pollution-related CV risk. Heat amplifies the adverse impacts of ozone and particulates on CVD. These pollutants are likely to be affected by climate change mitigation activities, and thus, efforts to curb pollution will likely reduce rates of cardiovascular morbidity and mortality.
Prolonged drought, such as that currently complicating life in the Southwestern United States, will lead to more dust and particulate pollution while increased rainfall in other parts of the country will cleanse the air but may create more mold and microbial pollution. In addition, drought, declining water quality, and increased temperatures contribute to the growth of harmful algal blooms that produce toxins that can be aerosolized and exacerbate asthma and respiratory diseases.
The good news: The June 2, 2015, issue of JACC included a paper demonstrating that home air purification provides clear cardiopulmonary benefits among young, healthy adults in a Chinese city with severe ambient particulate air pollution.5 The benefits included significant decreases in both systolic and diastolic blood pressure.
Another break in the clouds: the recent NIEHS report on climate change notes that cardiovascular and stroke risks resulting from climate change could be offset by reductions in air pollution due to climate change mitigation.
It's easy to shuck responsibility for reducing pollution in the Western world by simply saying, “Well, no matter what we do, there’s always China and India spewing tons of emissions.” And this is true, to some extent. China burns nearly half of the coal consumed on the planet and emits more greenhouse gases than anyone else. Industrial waste and human sewage clog the country’s waterways.
But Dr. Smith cautioned that this is a “let them eat cake” approach and suggested that a look back at the history of industrialization in the Western world tells a similar story of rapid industrialization leading to record amounts of pollution, including in the United States and England.
“There is a tension between having the economy to feed the people and develop the [desired] quality of life and yet not polluting the atmosphere,” he noted.
The Wounds of War
The effects of war in the 21th century are getting harder to ignore. Reaching far beyond the loss of life on the battlefield, which these days often encompass highly populated urban areas, stands the massive disruption to society: extreme poverty, millions of people displaced, unhygienic conditions, and scarcity of everything—food, water, medical care, electricity. Plus the psychological effects.
“The data show simplistically that if you’re living in a refugee camp, and I’ll take the example of the conflict in Syria now with about 2 million people migrating into Lebanon and quite a few to Jordan and Turkey, living in tents and with all the weather changes, that there are effects on total health but also cardiovascular health—lack of medications, lack of continuity, all these things,” said Dr. Zoghbi.
“No matter where you are in the world, war is similar. There is the acute effect and the lingering effect,” he said. “The priorities we take for granted—taking care of your health, taking medications, taking care of CV risk—these are all but eliminated and survival is the mode.”
Even in non-forced but large migrations, like the 700,000 to 800,000 individuals migrating to Texas each year looking for better economic opportunity, one sees issues with providing health care, added Dr. Zoghbi. According to estimates, only about 70% of newcomers to Texas are fully insured.
“Again, if you don’t have access to medications, prevention, including secondary prevention, then it will affect cardiovascular health,” he added.
Case Study: Syria
While it may be hard to imagine now, a few years ago Syria served as a model for developing countries, which typically lack reliable health and risk factor surveillance. There was an analysis of cardiovascular health among adults in Syria published in 2007,6 which in and of itself showed that while there once was functioning health care in the country, Syrians also exhibited a very high prevalence of risk factors for CVD. This study projected that about 85% of deaths in Syria would be related to CVD in the decade ending in 2016.
M. Zaher Sahloul, MD, a pulmonologist from the University of Chicago, Illinois, was born in Syria and immigrated to the United States 25 years ago. He is also the president of the Syrian American Medical Society (SAMS), which treated 1.3 million patients in Syria in 2014. He shared at ACC.15 some frankly shocking data on the state of health care in Syria today.
It is, quite literally, a dark time for Syria. After 4 years of civil war, 83% of the population is without electricity, 4 out of 5 Syrians live below poverty, and life expectancy has decreased from 75.9 year to 55.6 years (or 27% of life lost). A full 6% of the population have been killed, maimed, or injured.
Beyond injury and trauma—and in the case of Syria, the United Nations (UN) recently confirmed 72 uses of chlorine gas on civilian populations—war brings increased morbidity and mortality from non-communicable diseases, and resurgence of infectious disease due to decreased levels of vaccination, epidemics of infectious disease, and parasitic disease related to disintegration of public health systems and lack of clean water and electricity.
“So, for example, in Aleppo, which is the largest city in Syria, there is no garbage collection or disposal, and because of that we have seen an increase in leishmaniasis, lice, and scabies,” said Dr. Sahloul.
A return to the Dark Ages may be the best way to describe this situation, because it will take years, perhaps generations, to recover. Somewhat unique to these kinds of crises, noted Dr. Sahloul, Syria has experienced a systematic destruction of health care and the public health infrastructure, including the targeting of doctors, ambulances, and hospitals. These attacks have led to a dramatic reduction in medical personnel. “Before the crisis, we had about 30,000 physicians in Syria,” said Dr. Sahloul. “According to the WHO, we have about 15,000 physicians in Syria now, and that number is dropping by the day.
“The public health system is overwhelmed by the crisis, by the trauma, and the violence…” said Dr. Sahloul.
As of March 12, 2015, Physicians for Human Rights documented that 610 Syrian medical personnel had been killed in the last 4 years, with 139 of them tortured to death or executed, as well as 233 attacks on medical facilities, 88% of them by governmental forces. Of the 1,171 doctors practicing in Ministry of Health hospitals in the Aleppo Governorate, only 292 remained as of September 2014.
Just as climate change contributes to pollution (and pollution-related CV risk), global warming contributed greatly to the situation in Syria. Dr. Sahloul noted that in the 5-year span between 2005 and 2010, Syria experienced its worst drought in the last 10,000 years; this led to the displacement of about 2 million people. According to several studies, the net urban influx resulting from the drought is considered to be a causal factor in the 2011 uprising that led to the prolonged and continuing civil war.
Syria is far from the only country dealing internal strife on a massive level. The UN and its humanitarian partners are currently responding to four Level 3 emergencies (not counting Ebola): Syria, Iraq, Central African Republic (CAR), and South Sudan. Level 3 is the UN classification for the most severe, wide-ranging humanitarian crises based on scale, urgency, and complexity of the needs, coupled with the lack of domestic capacity to respond.
The numbers are staggering: 7.6 million displaced in Syria, 2.5 million in Iraq due to fighting between ISIS and government troops; 2.7 in CAR, and 1.5 million in South Sudan.7
According to more UN data, by the beginning of 2014, there were 51.2 million people forcibly displaced, which is the highest on record since the refugee crisis that followed World War II. Syria alone accounted for about 9 million of these refugees.8 For perspective, the population of Spain is just over 47.2 million; South Korea has a population of 50.2 million.
A Call to Action
At the end of his talk at ACC.15, Dr. Sahloul queried the audience on their willingness to participate in medical missions to help patients and refugees in areas of conflict. A full 80% of the audience (albeit a select group, given the fact they chose to attend the session) expressed willingness. Dr. Sahloul stressed that there are safer places to help serve than Syria and volunteers would be sent to less treacherous locations.
In his presidential address at the opening of ACC.15, Immediate Past-President Patrick O’Gara, MD, called upon the ACC and other societies “to lead during a time that seems to be completely devoid of compromise, and in a place where often community interests seem to be subordinated to individual rights.
“It’s easy to think at times that we operate in a vacuum, especially when we come to national meetings. But we live in a world of chaos; we live in a world of terrorism, climate change, air pollution, dwindling resources, intolerance, and inequality,” said Dr. O’Gara, showing slide above (Figure 1).
“Once you think [about it,] there is a bigger picture confronting us and therefore a greater responsibility.”
- Portier CJ, Thigpen Tart K, Carter SR, et al. 2010. A Human Health Perspective On Climate Change: A Report Outlining the Research Needs on the Human Health Effects of Climate Change. Research Triangle Park, NC: Published by Environmental Health Perspectives and the National Institute of Environmental Health Sciences. doi:10.1289/ehp.1002272 Available: niehs.nih.gov/climatereport.
- Brook RD, Rajagopalan S, Pope CA III, et al. Circulation. 2010;121:2331-78.
- Newman JD, Thurston GD, Cromar K, et al. J Am Coll Cardiol. 2015;65:1150-1. content.onlinejacc.org/article.aspx?articleID=2173083
- World Health Organization. News release. who.int/mediacentre/news/releases/2014/air-pollution/en/. Accessed on May 26, 2015.
- Chen R, Zhao A, Chen H, et al. J Am Coll Cardiol. 2015 June 2;65:2279-87.
- Maziak W, Rastam S, Mzayek F, Ward KD, Eissenberg T, Keil U. Ann Epidemiol. 2007;17:713-20.
- United Nations Office for the Coordination of Humanitarian Affairs. Emergencies. unocha.org/where-we-work/emergencies. Accessed on May 15, 2015.
- United Nations. ‘War’s Human Cost’: World’s Population of Displaced Tops 50 Million, UN Refugee Agency Reports. un.org/apps/news/story.asp?NewsID=48089#.VVTwH9NViko. Accessed on May 14, 2015.
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