Observations from the Roundtable: Health in a Changing Environment

Monday, April 8, 2019
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Human societies have generally made great progress over the course of history in the mastery of their surrounding environments, climates, and biomes. And the experience of the United States is emblematic of this, across a variety of measures—with significant reductions in air and water pollution, in weather-related mortality, in malnutrition, and in the burden of disease. Progress has been driven by a combination of technology, markets, and governance. Oftentimes difficult social and regulatory choices over the past half century, enabled by technological innovation and ongoing incentives for investments, have allowed this country to stay one step ahead of the variety of environmental and health risks it faces.

It is perhaps indicative of the consistency of this progress that the continued fragility of modern man’s relationship with the environment goes unappreciated. But with anthropogenic climate change and other human-ecosystem impacts, some of these natural risks are set to grow faster, stronger, or in newly unpredictable ways. Our exposure to damages may also increase in the United States, which has an increasingly prosperous society with more built assets at risk, alongside an ageing population that could be more impacted by extreme weather or other ecological events. Even today, despite major successes in recent decades, conservative estimates still ascribe more than 10,000 American deaths each year to pollution. The environment is not a solved problem. Governments will have to find new ways to stay ahead of these changes and protect their populations from threats, whose mitigations may now be taken for granted.

Our expert authors and roundtable discussants identified a number of such under-appreciated environmental risks going forward. And while many of their observations are not scientifically novel, they are put in terms that make them accessible to citizens and politicians, who tend to prioritize today’s policy problems before tomorrow’s. Moreover, they propose to use new technologies, particularly in diagnostics, to facilitate implementation of traditional approaches to countering many of these increasing risks.


American governance and private innovation have of course helped public health make great strides over the past century. In 1900, it is estimated that at least 10,000 Americans died each year from malaria, and at least that many from smallpox. Domestic transmission of both pathogens was essentially eliminated by 1950. U.S. life expectancy rose from 50 years in 1900 to 79 today—and over the same period mortality for children under five fell from nearly 2,000 deaths per 100,000 children, to 140 in 1950, and just 25 today. Since 1980, U.S. infectious disease deaths of all types have fallen by nearly one-fifth.

But infectious diseases, which had declined during the 20th century, are making a comeback, and our discussants argued that pandemics once again pose a major threat to humanity. Part of this is due to growing global human contact. Mobility is increasing everywhere alongside the growing affordability of longer distance travel. Since the 1980’s anthropologists have posited the concept of a “travel-time budget”: that on average individuals in societies spend approximately the same amount of time each day, roughly one hour, devoted to traveling to and from work. As technologies improve, people become richer, and the price of mobility falls, this results in people choosing to travel longer distances at higher average speeds for leisure or economic activity. This improves the productivity of labor markets, but it also creates new pathways for the spread of infectious disease.

Global urbanization rates are also rapidly increasing, especially in the developing world, due in part to demographic shifts. In parallel, increased immigration to developed countries in temperate regions from source countries across the global tropics—and ongoing family ties to home—has increased the prevalence of tropical sickness in northern hospitals. As our panelist and emergency room physician Milana Boukhman Trounce put it, ubiquitous global air travel has become an infectious disease “super vector.”

Meanwhile, human populations are also changing the nature of their contact with animal disease pools or vectors, due in part to climate change. Changing precipitation and temperature patterns, for example, are redistributing the spatial and temporal incidence of disease spreading mosquitos—perhaps lower incidence than today in some areas, but higher in others, including the introduction of tropical diseases into the United States. For another example, African Ebola outbreaks are not new, but the 2014–2015 Ebola outbreak ended up affecting far more people than previous outbreaks, spreading across the entire continent rather than within a single village, with even worldwide impacts due to international travel. Similar dynamics now apply to the spread of predictable outbreaks like the annual flu as well as other infectious organisms.

Beyond these natural drivers, the future also holds the risk of disease outbreaks from accidental or even deliberate means as the cost of genetic engineering rapidly declines. Humans ourselves are at risk from this, but so are our livestock and other agricultural economies.

What can governments do about this threat to mitigate new risks and extend the significant progress in public health made over the past century? Our discussants considered what has worked in the past, what has not been effective, and the potential for new approaches.

Prevention could take two forms. One promising route would be mitigating the newly evolving activity of vectors. Mosquito population control has been practiced for over one hundred years to immense human benefit. Going forward, newly-developed genetic engineering “gene drives” offer numerous new options, with varying tradeoffs between efficacy and ethical concerns or the risk of unintended consequence: such techniques can reduce vector (i.e. mosquito) populations, limit vector reproduction, or inhibit the ability of the vectors to transmit a pathogen. In many cases the biology to do so has already been developed. In weighing the governance framework for deployment of such technologies, we would urge that their potential costs and benefits be considered not against a standard of perfection but of a status quo in which the human burden of infectious disease is already large—and set to grow in a changing world.

Preventing new infection through new vaccines is harder. Humans and the animals we value are potentially vulnerable to thousands of strains of viruses, which can mutate rapidly. Developing vaccines or drugs for all of them, which can easily cost over $1 billion each, is not feasible. Even today’s widely administered flu vaccine, for example, which is developed ahead of each flu season based on predictions of the form the virus will take, is of uneven effectiveness because the virus mutates rapidly. And anti-viral drugs like Tamiflu have shown to be of little value in easing virus symptoms, apart from in patients with already-compromised immune systems.

But could new technologies help speed the development of disease treatments once an outbreak has already begun? Traditional vaccines may take a few years to develop, but our panel discussants advised that even a large infectious disease outbreak will generally run its course in 12–18 months—before conventional vaccines would ever be ready.

One strategy that could help is more rapid detection and early characterization of an outbreak. Panelist and biotechnologist Stephen Quake described how biology has become an information science—that is, one driven by data—enabled by low-cost and scalable cloud-based computing and data storage. Meanwhile, the cost of sequencing DNA has dropped by orders of magnitude over just the past 10–15 years, at rates comparable to “Moore’s law” improvements through the 1980s, 1990s, and 2000s in the cost performance of microchips. Together, these two advances mean that biologists have rapid access to the genomes of many organisms, including human or animal pathogens at an early stage of a pandemic. When using the right tools, this can cut months out of the detection process.

These same technologies can help develop rapid therapies. Quake described, for example, how his team was able to take DNA samples from a population at an early stage of a novel dengue outbreak and rapidly sequence them against a cloud database of known DNA patterns to look for new strands—including disease antibodies that had been generated through the immune response of some of the infected individuals. Reproducing those highly targeted antibodies and delivering them to other infected or at-risk individuals offers a new path to rapid, almost “in the field” treatments.

Some challenges are less amenable to technological solutions. A large pandemic would of course have direct costs on U.S. citizen health. But even a smaller infectious disease outbreak with high mortality rates could be debilitating given the somewhat prosaic difficulty in providing surge capacity—additional hospital beds, clean rooms, water supplies, etc.—in the health care system. Our discussants described from their firsthand experience how even a very large regional trauma facility, such as the Stanford Hospital, could host, at most, ten Ebola patients at one time—and that even that would require the complete shutdown of the hospital’s cardiac wards.

While the development of rapid and accurate diagnostic tests such as those described above would be crucial—i.e. “at home pregnancy tests for Ebola”—the historically effective solution in such circumstances would be public health measures: isolation (of those with the disease) and quarantine (of those exposed). Local governments at the county or city level would be responsible for creating and enforcing bans on public gatherings, school and business closures, and strict home quarantine and isolation. Doing so has always been difficult, with one panelist observing that during the 2003 SARS outbreak, “even Canadians in Vancouver didn’t want to comply [with quarantines].”

New, quick, and accurate diagnostic tests could enable effective implementation of isolation and quarantine. In addition, panelists speculated whether new information and communication or logistics technologies could facilitate such difficult-to-enforce measures through location tracking, telemedicine, or the automated delivery of food, water, and supplies. Overall the panelists argued that “the public sector is not sufficiently preparing for this.” While local public health departments have protocols, do drills, and receive guidance from the federal Centers for Disease Control and Prevention (CDC), “there are too many cooks in the kitchen.” A large-scale disease outbreak is not just a medical event, but also one of public safety and security: “It’s chaos every time, and it is always reactive.” Looking at how warehousing and logistics technologies are developing, panelists considered how the U.S. private sector might end up delivering many needed services in such an outbreak, and the market incentives and coordination that governments could consider to help enable that.

Climate Change and Environmental Pollutants

A combination of technology and policy within a market incentive framework has led to a reduction in many environmental pollutants in the United States, including ozone, particulate matter, carbon monoxide, sulfur dioxide, nitrogen dioxide, lead, benzene, and mercury. But our panelists asked how much of a threat remained and if that progress might be reversed through interactions with concurrent global climate change.

The detrimental impacts of small particulate matter remain severe in the developing world. While Beijing and New Delhi are extreme examples, 92 percent the world’s population lives in areas where air quality does not meet WHO standards. Particulate matter can be inhaled deep into the lungs, bringing hazardous substances into the bloodstream. Exposure can have economy-wide impacts, with a range of estimates in China attributing annual GDP growth rate losses of between one and four percentage points to health and childhood developmental costs associated with air pollution. Meanwhile, indoor cooking with wood or dung, a method relied upon by over a billion people in Africa and South Asia without access to cleaner commercial fuels, produces smoke with particulate levels 100 times higher than acceptable levels and results in millions of deaths annually.

Even in the United States, the changing risk of and exposure to regional drought, floods, and wildfire smoke under changing regional climate regimes may put the respiratory health of the public at risk. Going forward, discussants argued for increased use of controlled burns, for example, which burn less intensely than uncontrolled wildfires and therefore result in fewer health impacts for those exposed to resulting smoke. Rising temperatures may increase Americans’ environmental exposure, broadly defined: a longer and more intense allergy season, the spread of insect-borne diseases, more frequent and dangerous heat waves, and heavier rainstorms. One emerging area of policy attention has been ingestion of mercury and microplastics through seafood consumption.

There is reason for optimism that we can successfully handle these risks. In the United States since the 1970s, we have seen substantial, sustained reductions in per capita emissions of air pollutants such as sulfur dioxide, nitrogen oxides, and chlorofluorocarbons, as well as reductions in exposure to toxics such as asbestos and lead—despite overall economic activity quadrupling over that same period. Today's per capita energy-related sulfur oxide emissions in the United States, for example, are about 85% below levels just 25 years ago, while nitrogen oxide emission intensity has fallen 60%. At that time, particulate air pollution from U.S. coal fired power plants alone were thought to contribute to 30,000 American deaths annually; today, with market-driven fuel switching to natural gas as well as improved (and often government-mandated) emissions controls, that number has fallen by 90 percent.

In addition to conventional pollution mitigation measures, our panelists suggested other emerging technologies that might help reduce these public health risks going forward. Even in developed countries, the elderly remain at risk from heat waves, and heat is already the largest weather-related killer in the United States: low-cost wearable devices that automatically report on cumulative heat exposure, hydration, and body response could help in an ageing U.S. society (while deaths from extreme temperatures are difficult to measure, studies suggest that extreme heat deaths have already gradually declined in a variety of U.S. cities over the course of the 20th century, and this progress could be further extended). Emerging technologies over the last decade now show promise for using the same antibodies that cause allergies—which already affect 60 million Americans at a cost of $20 billion per year in lost work days—to create effective therapies for them. And going forward, advancements in regenerative medicine may also be able to play a role in mitigating the effects of pollution-related diseases such as lung disease. Our discussants noted that where markets for such services or therapies exist, U.S. industry is already moving rapidly in using these technologies to develop valuable new consumer products. They should be encouraged.

Ecosystem Services

Our panel leader, biologist Lucy Shapiro, observed that even optimistic projections of reductions in greenhouse gas emissions over the next century are likely to results in significant climatic changes, including potential disruptions to valuable ecosystem services such as environmental pollution filtration, groundwater, seasonal precipitation storage, pollination, biodiversity, agricultural productivity, and other food chains. Since before the founding of our country, we have struggled against weather and environmental threats, sometimes at great cost—consider the plight of early European colonists, for example. Today’s climate change is perhaps unique though in the number of ways it will affect various aspects of human prosperity. It is also unique in that the development of modern climate science tools helps us to anticipate these changes with some degree of reliability. From a policy perspective then, as societies strengthen their efforts to reduce warming, they should also be planning for—and budgeting for the costs of—how to ameliorate the expected human impacts of these damages.

We are already seeing the consequences: rising relative sea levels alongside coastal subsidence, causing major population displacements; extreme fires and storms; acidification and warming of ocean waters, leading to decimation of coral reefs; changes in food production; and accelerated extinction of species.

Consider tropical coral reefs, about half of which according to our panelists have experienced heat stress or bleaching, with adverse consequences for fish and other marine life they shelter and support. Recently, scientists have discovered how some corals have naturally adapted to warm water and acidification, and that these populations might be used to help seed new growth in damaged areas through transplantation. While some may find this an unsatisfying concept, it echoes the history of human cultivation of the terrestrial plant biome through intense forestry or cultivation practices.

Another example is storms. Extreme precipitation events have increased in the United States over the last century. But the incidence of floods in this country has remained essentially flat, and deaths from floods have declined on a per capita basis. This is due in part to proactive efforts to control runoff and waterways through infrastructure development or complementary management practices. Similarly, despite incidences of extreme weather, tornado and lightening deaths declined on an absolute basis in the second half of the 20th century, aided by upgrading building codes, detection technology, and emergency response. This has not been a cheap course of action, but it has been worthwhile.

Similarly, we may find ourselves in the United States forced to take novel steps to avoid increased economic climate damages. For example, this country has seen enormous successes in improving the productivity of our agricultural system: U.S. corn farmers produced 30 bushels per acre of farmland in 1900, 40 per acre in 1950, and over 150 bushels per acre today; soybeans and wheat have seen similar productivity growth; and each U.S. milk cow today produces 2.5 times more milk than its predecessors of 50 years ago. And in recent years, agricultural biotechnology has been largely focused on extending the gains of the Green Revolution by further improving those yields. With a changing climate, however, the field may now need to shift more towards the development of drought-, heat-, or disease-resistant crop varietals instead, with the associated opportunity costs of doing so.

Or, in parts of the country that will experience drought, new water infrastructure development may be necessary to both store seasonal runoff and improve end use efficiency, such as in agricultural irrigation, industrial, or residential use; the economics of undertaking new capital investments in an era of declining overall utilization are daunting.

Day to day human activity is likely to be affected too, which can result in a sort of constant tax on normal livelihoods and commerce. Heretofore in modern U.S. history, for example, vector population controls and a generally temperate climate have insulated us from debilitating tropical diseases, with all their ensuing healthcare costs and drains on productivity. But with climate change, mosquitos are moving north. We will need to redouble our diagnostic, treatment, and eradication capabilities in order to hold our ground.

Going forward, maintaining our relationship with our environment—and obtaining the services it provides for us—may simply take more effort.

The Intersection of Technology, Markets, and Policy in an Emerging World

The concrete nature of the challenges presented in this volume drive home the point that policies to address climate and the environment should focus less on what may or may not happen in the future, or on abstract numerical targets and complex agreements, and more on what can feasibly and responsibly be done today to reduce our risk. Many of the steps we could take today in anticipation of any future risks would start accruing benefits even now given that we already manage or mitigate our environment on many fronts.

This was one of the lessons of what is perhaps the most effective coordinated international environmental strategy in history, the Montreal Protocol. At first, the science was uncertain, but it was compelling enough that were the scientists to be right, the environmental results would be unacceptable. So at first we took obvious, easier policy steps to addressing the chlorofluorocarbon problem—but we also got American companies started on the technology development to give us better options to address the more difficult aspects of the problem in the future. By the time that the Antarctic ozone hole was observed, those new technologies were close enough to being mature that we could go ahead with a specific and binding agreement we were confident that we could actually fulfill. We've done this before.

Similarly, one recurring theme in the day's discussions was the growing relationship between climate change and other "conventional" environmental concerns like air, water, and soil pollution. Some of these systems have scientific links. But they are also increasingly linked in the minds of the public and in policymaking. Consider key recent federal "climate" regulations such as the 2015 proposed Clean Power Plan, or even some vehicle fuel economy standards, where cost-benefit analyses in their favor were actually dominated by co-beneficial reductions in local and regional air pollution. And whereas public polling by Pew Research suggests year after year that climate change remains relatively low on U.S. voters' list of priorities for Washington, D.C., maintaining an overall healthy environment consistently ranks highly across party affiliations. Globally speaking, contemporary America's natural environment is one of our country's best assets, and we should be looking to maintain that alongside vibrant economic growth.

Some of the problems are not even so complicated. Think of the existing nuclear power plants in this country, which provide substantial amounts of clean energy. Some are now unexpectedly having to be shut down by their operators because they are losing money in today's low-cost electricity markets. But we know that when those plants get shut down, they are replaced by polluting alternatives. Fixing this doesn't take some aspiration for the future (though we should be investing in even better nuclear power technologies for the future, too). Instead, this is the sort of three-way intersection of technology, markets, and policy that we will increasingly encounter in a changing environment. While these are the sorts of questions state and federal agencies have always had to respond to, as the natural pace of change gets faster on the other two of those three dynamics, government will need to get faster at identifying and responding to change as well.

Importantly, while some of these challenges described in this volume are new, and others are as old as civilization, our panelists—themselves scientists, doctors, or engineers—remained compelled by the optimism of an American spirit of discovery and innovation to take them on. This was tempered only by their regret in the strained relationship between science and policy in this country, where knowledge and promise are too often selectively ignored or weaponized by both political parties.

They concluded with a plea for the foundational long-term importance to the nation of investing in science and engineering. Markets enable a host of groundbreaking science and health innovation by private entities. But public funding is still crucial in serving earlier stage research that does not offer good near-term private investment prospects, and for which socially valuable intellectual property can be made more widely available. In a time of newly emerging challenges, our discussants particularly called for a shift in public funding towards riskier but potentially game-changing forms of research and development that get sidelined by conventional funding processes, which tend to emphasize lower-risk, marginal advancements. Where governments have dialed back those risky research ambitions, philanthropy has tried to fill the funding gap, but its reach is more limited. At the same time, discussants sought to rebalance the working relationship between Washington, D.C., and the optimism of labs such as theirs around the country. As mentioned above, Stephen Quake’s contribution to this volume reviews the many groundbreaking research projects being conducted here at Stanford and partner institutions, as well in industry. We are fortunate to be at the center of such great work, and the vibrant culture of investigation and discovery here speaks to the value of fostering such efforts. To conclude with one panelist’s summation:

“This argument—about if you should do very basic research with no obvious endpoint and just deal with things that you know how to manipulate and apply them to a different project—is a strange argument.

If you don’t push the boundaries of understanding this world that we are living in, then when we are faced with a complete skewing of the ecosystem of the globe (which we are dealing with now) without new kinds of understandings of how living beings, living organisms can survive changes in their environment—we are being, if not short-sighted, then we are being criminal. It just makes no sense whatsoever.

But somehow, we have to do both. We have to continue digging for new ways of understanding the world around us, so that we can mitigate disasters, and we have to cleverly use what we already know about to create ways of dealing with them and the immediate situation. So you have to deal both with the future, and with the present, and have enough science, and enough people who are making decisions listening to the science, so that we make intelligent choices.

And right now, both the world ecosystem is skewed, and our political system is skewed, and these things must come together, or I fear for what’s going to happen to life on this earth.”