Note: This transcript is auto generated and lightly edited.
MARY: When it gets hotter, we see violence rates rise, increased emergency room visits, hospitalizations related to cardiovascular disease, related to diabetes, electrolyte imbalance, renal failure, respiratory outcomes. And I could go on and on when we talk about this. And we of course know that these heat related health impacts are greatest among children, adults over 65, people with disabilities, people with mental health or substance abuse disorders, pregnant people, and people who have lack of access to cooling, as well as outdoor laborers.
MONICA: Welcome to Policy for the Planet, a new bimonthly podcast exploring the global response to the climate crisis.
I'm Monica de Bolle, a best-selling author and senior fellow at the Peterson Institute for International Economics, based in Washington, D.C. My work bridges the fields of economics, science, public policy, and public health–all under an international lens.
In each episode, I speak in-depth with experts to understand how governments are responding to the monumental challenges of the climate emergency. We'll unravel the complex tradeoffs of different policy choices to steer us toward sustainable practices and public well-being.
Welcome to the conversation!
As weather patterns shift — and extreme events become more frequent — public health will inevitably be impacted.
Joining us today is Dr. Mary Hayden, a behavioral scientist and Research Professor at the University of Colorado's Lyda Hill Institute for Human Resilience, affiliate scientist at the National Center for Atmospheric Research (NCAR), and Adjunct Faculty at the Colorado School of Public Health. She currently serves as a member of the Board on Environmental Change and Society at the National Academies of Science, Engineering, and Medicine and was the Lead Author on the Human Health chapter of the 5th National Climate Assessment (NCA5).
Mary's interdisciplinary work integrates physical and social sciences to shed light on how climate change impacts human health, with a focus on vector-borne diseases such as Dengue Fever and Lyme disease.
Today, she shares the far-reaching implications of climate change on public health and discusses strategies for building resilience in the face of these growing challenges.
Welcome to the show, Mary. I am very excited to talk to you about climate and health and specifically the health implications or the health consequences, I should say, of climate related issues, climate change and all the things that we have been going through. So on that note, I'd like to start us off by asking you to please tell us about the connections between climate change and health from excessive heat to the spread of mosquito borne and other diseases.
MARY: Well, and thank you, Monica, for inviting me. I'm very excited to be here today. So I want to just start out by saying, you know, climate change is harming human health. And when we think about it, we often think, it's just physical health. OK, just but not just. But it isn't. We're seeing negative impacts from climate change on mental health, on spiritual health and community health and well-being.
And we see this because we're seeing so many climate-related weather events that impact the US population. And this includes floods and droughts and wildfires, extreme temperatures. As we all know from recent events, hurricanes, right, and different kinds of storms that we're seeing. And unfortunately, with climate change, all of these are expected to increase in frequency, in intensity, and in extent. So we're going to see them over a larger area in the United States as well.
MONICA: It is difficult, isn't it, to get people to be attentive to the health implications of climate change, to get them to understand that climate change is a health issue. Is it not?
MARY: Yes. Absolutely. And with the health risks that we can expect from climate change include higher related, higher rates of heat related morbidity and mortality for one. And we've seen that with the extensive heat we've had in this country in recent years, where we're experiencing increasing geographic range of some infectious diseases. We're seeing greater exposure to poor air quality, whether it's from wildfires or air pollution in cities, in adverse pregnancy outcomes, higher rates of pulmonary, higher rates of neurological, higher rates of cardiovascular diseases, and worsening mental health in response to all of these problems we're facing.
MONICA: So in other words, we're kind of seeing the gamut of diseases in a sense, because we're seeing a rise in non-communicable diseases.
MARY: Right, absolutely. And I just want to mention that those risks that I talked about, they have an effect on every single person in the United States, but they have disproportionate effects on communities that have been under-resourced and overburdened and individuals such as pregnant people, communities of color, children, for example, we're seeing such mental health issues in children, people with disabilities, people who are experiencing homelessness. And of course, we mentioned the chronic diseases and older adults.
So you could really say that climate change is a threat multiplier. For example, when we talk about fence line communities and these are communities that are located adjacent to hazardous industrial facilities. And of course they're disproportionately BIPOC and low wealth communities. these communities all face higher risks from chemical and from industrial disasters when we see extreme weather because often these are disrupted.
So, for example, in Colorado, when we see floods, we often see our waste facilities are inundated with water and they're not able to clean and do what they need to do all of our water facilities. And we also know that about 70 % of Superfund sites, so these are locations that are already contaminated by hazardous materials, right? They're located within one mile of federally assisted housing. And of course, these houses are usually and disproportionately inhabited by people of color, individuals with low wealth and persons with disabilities.
MONICA: It provokes massive social dislocation on top of the social dislocation that already exists. So it is really an existential issue as in how do we survive because we're talking about health, we're talking about living conditions, we're talking about water, we're talking about air, you know, all the things that are vital to keep us going.
MARY: Right, and we really need to focus on this. We need to focus on creating climate resistant health systems. We need to focus on adaptation measures, and we need to focus on mitigating greenhouse gas emissions if we're going to protect human health. And we really need to. And I'm thinking that later on down the line when we talk about other things, I'd like to give some examples of ways in which we can do this.
MONICA: Before we do that, to talk a little bit about the research that you've done on the infectious disease side. So specifically Lyme disease and dengue. So if you can please talk about that and your findings pertaining to the US because you have a lot of interesting findings in your research.
MARY: Sure, and thank you for asking. Of course, this is near and dear to my heart. And Lyme disease has been nationally notifiable as a disease since 1991. And we've been seeing an increase in not just the cases, but also the geographic range of the vectors of Lyme disease, as well as an extended season for transmission. And we call that the shoulder season. So we see it starting earlier in the year and going longer in the fall.
So extended season for transmission. And we've seen a steady increase in Lyme disease and other tick-borne diseases actually over the past 20 years due to climate change, but also other factors such as land use change. I mean, I don't want to just pin it all on climate change because there are multiple factors that come into play here.
But estimates for Lyme disease in the US are in excess of 400,000 cases annually. And these are clinical cases, OK? So these are not lab-reported cases, but clinical cases estimates. And approximately 80% of all reported cases of vector-borne disease in the US are tick-borne diseases. So it's really a problem.
MONICA: What about dengue, Mary, and other mosquitoes? So moving from tick, from Lyme disease and tick-borne diseases to mosquito-borne diseases, we are also seeing a spread and a dissemination into areas that were not previously endemic of these diseases, right?
MARY: Absolutely. And we see many reasons for the expanding range of these disease vectors and climate change is of course one. But unplanned urbanization in many parts of the world where we see unregulated settlements, inadequate municipal services, people don't have piped water so they have to store their water which provides a perfect breeding place for these mosquitoes, we see there's a lack of or very limited trash collection. And with the proliferation of plastic, so these non-biodegradable receptacles, even bottle caps, provide a place for the mosquitoes to breed.
So in the U.S. what we're seeing is that climate change is altering the diversity and distribution of mosquito vectors, and particularly those mosquitoes that transmit dengue, Zika, and chikungunya viruses. One of the more interesting ones, I think, is Aedes albic pictus, which was introduced through the used tire trade from overseas into Louisiana in 1985. And now we see the Asian tiger mosquito, as it's known, has spread all the way north, as far north as Maine, all the way west. into Nebraska and we're seeing it on the west coast. And this is a mosquito that thrives in the tropics, in the subtropics, and also in temperate zones. So it's very, very difficult to control this because it's also a container breeder.
And as I mentioned earlier, a bottle cap will serve just fine as a mechanism for the mosquito, which the mosquito delays eggs and to the larvae and pupae to survive and Aedes aegypti, which is the yellow fever mosquito. And one that's been around for a long time, it was responsible for yellow fever outbreaks as far north as Philadelphia in the 1700s. So I think it was 1793 that we saw an outbreak in Philadelphia that killed over 5,000 people. And we're now seeing the northward spread of Aedes aegypti in California. There was just a recent report of it spread into Santa Clara County, which is in Northern California.
So dengue continues to be a risk in the contiguous United States in the US Caribbean, Hawaii, US affiliated Pacific islands. We've actually seen 11 locally acquired. That means that nobody traveled. When we talk about locally acquired, we call it autochthonous, meaning there was no travel history associated with these cases. 11 locally acquired cases of dengue in California, nine of which were in LA County. We've also seen 49 cases in Florida, this year throughout parts of southern Florida. Last year we saw 178 cases in Florida, all locally acquired, and of course there are many many many more cases. One of the things that's interesting about this is that 75% of the people who have dengue are asymptomatic, so we don't even know that they have dengue, and so we probably have a lot more local cases than just what we see from the symptomatic people.
MONICA: So Mary, we know that these vector-borne diseases and these mosquito-borne diseases, tick-borne diseases, and so on are on the rise in the US.
But of course, we know of dengue that there are four different types of the virus. And if one person has an asymptomatic case of a certain virus and then catches a different dengue virus a second time, they can have complications. the question that comes to my mind is how aware and how urgent is the perception about climate change, the spread of these infectious diseases and infectious agents, and what different localities across the country are doing to combat that or if that sense of urgency is there.
MARY: I don't know if you knew this, but this year CDC had actually issued a notification that physicians in the US should be on the alert for dengue fever because of the rapid increase in dengue fever in Central and South America.
But really the thing that we're focusing on here is climate change because it's a significant contributing factor to this increase in vector-borne disease cases that we've seen in the last 20 years because we're seeing rising temperatures which makes the environment usually more hospitable for the mosquitoes as well as extensive rainfall.
And you know, it's an interesting phenomenon with rainfall because when you have hurricanes, you often have saltwater intrusion and so aedes aegypti doesn't survive that very well. But then as the waters recede and the floodwaters are still there, then we see a proliferation of the mosquito.
And so...you know, we're trying to adapt to these changing risks and we have new technologies, of course, to prevent transmission, but we still need a lot more and we need them urgently. We have a very difficult time in much of the developing world controlling this mosquito.
We use insecticides, but of course we're seeing so much resistance now that they're becoming ineffective. We've seen, as you mentioned, recent advances in vaccines, particularly with the dengue vaccine, but we're also using spatial repellents in some parts of the developing world. And I'm not sure if you know what those are, but if you imagine an eight by 11 sheet with a little bit in the center that has a repellent that can volatilize into a room and keep the mosquitoes at bay, for a certain period of time, usually around two weeks, this seems to be a pretty effective mechanism. And one of the things that's nice about spatial repellents is the mosquitoes are not physically going on to this repellent. And so there's less resistance to the insecticide that's being volatilized. And so it's inexpensive and an interesting way to do this.
We're also using genetically modified mosquitoes. I know that you know in Brazil, they have had releases of genetically modified mosquitoes. This is where the males are sterile. And so there are no progeny when they mate with the females. But we're also using Wolbachia, which is a naturally occurring bacteria that reduces the transmission of the virus, of dengue viruses, for example. So we have a few things that we can use, but these novel adaptations are really not operational.
And you know why? Well, funding is one big thing, course, regulatory status. And of course, the infrastructure needs to build facilities to develop these mosquitoes. I mean, it's so expensive to do this that it's, yeah, we need more buy-in from communities and decision makers.
MONICA: That is such a rich set of issues that you just raised.
MARY: And it's not just, I just want to add one more thing in there, that we need community engagement as well. And that's one of the things that we're starting to see a little bit more now, which is heartening, because at first, many of these novel approaches were being introduced into communities without the community's consent.
And when you do that, people are up in arms. You're releasing more mosquitoes into my community. What? What are you doing? And so there's such a need to educate people about these technologies before we actually go in and release them.
MONICA: And that is so, it's great that you mentioned it because there were things that you mentioned about these existing technologies that are currently being used. And of course, nothing is sufficient unless you have buy-in from everyone, as you've just said. But some of them are really interesting. The one that you said about having the insecticide in a particular space so that it can sort of.
MARY: Volitalize.
MONICA: Yeah, volatilize or aerosolize. Can we say that?
MARY: Yes, sure.
MONICA: So aerosolize into the space, right? To control the mosquitoes or at least to keep the mosquitoes at bay for a time.
MARY: Especially indoors. I think you can probably see one of the issues with it, right? What happens when you're outdoors? And with Aedes aegypti, it's a day-biting mosquito that will bite you indoors or outdoors. It doesn't care where you are. And so we also like to suggest that people take personal protective measures so that they wear long sleeves and long pants. And this is kind of difficult in some of the climates in which we find Aedes aegypti where it's really hot and really humid and people are not comfortable wearing this type of clothing. We also recommend EPA repellents such as DEET or picaridin. But of course that's often something that's outside of the ability of people to afford in many parts of developing world.
MONICA: And before we turn to funding and to cooperation between countries, all these very difficult questions, perhaps the most difficult, I do want to hear about your work on excessive heat because I think there's so much there and it's such a rich set of issues that you raise there as well.
MARY: Yeah, yes. And so we know, and we've experienced so much excessive heat in the US recently, as you know, higher temperatures are associated with adverse pregnancy and birth outcomes, which is a problem. We find low birth weight. We find all kinds of issues with heat related exposure, mental health impacts. We've known this for a long time. When it gets hotter, we see violence rates rise, increased emergency room visits, hospitalizations related to cardiovascular disease, related to diabetes, electrolyte imbalance, renal failure, respiratory outcomes. And I could go on and on when we talk about this. And we of course know that these heat related health impacts are greatest among children, adults over 65, people with disabilities, people with mental health or substance abuse disorders, pregnant people, and people who have lack of access to cooling, as well as outdoor laborers.
MONICA: Construction workers, right?
MARY: We really see absolutely exposed to that heat for extended periods of time and migrant workers who are providing food for our tables.
MONICA: Absolutely.
MARY: So we expect that these heat-related death and illnesses will continue to increase unless we see climate adaptation and mitigation policies that are being implemented.
MONICA: In these communities where you see the greatest impact of, say, either excessive heat or mosquito-borne illnesses or tick-borne illnesses, do you see a sense that the community clearly understands that those issues that they're facing have to do with climate change?
MARY: Well, we can say we know that there are populations that are disproportionately affected and I've gone through the entire litany of those right but I think that one of the things when we think about it is let's let's talk about air conditioning for example okay and we know that there's limited access to air conditioning in low-wealth communities we know this is a fact we've done national surveys that show that 20 percent of the population may have air conditioning, but if it's broken, they can't afford to fix it, or they may have air conditioning, but they can't afford the electricity costs to run their air conditioning sufficiently to cool themselves, or they may not just be able to afford air conditioners, period.
And I think that, you when we think about air conditioning, I think it's an interesting one too, because we know that it can, of course, exacerbate urban heat islands because of the heat that goes out, but also what it does is result in a lot of power outages.
Power outages affect everybody. It's not just affecting people who are under-resourced. It's affecting everybody. And so while some people may have generators to help mitigate the impact of power outages, others don't. And so I think it's a sobering thing to see for everybody in the community, and particularly when you look in the aftermath of a hurricane, for example, when there are power outages for extended periods of time where people don't have power for weeks on end. And if you have high temperatures, everybody is subject to that type of uncomfortable condition.
MONICA: Mary, what is the United States doing when it comes to excessive heat and all of the issues that you mentioned, the health issues that are associated with excessive heat and they're very serious health issues? What are the strategies that the US is implementing to address this?
MARY: So I think that there are a number of different strategies that are being undertaken, but I think the important thing to remember is that many of these strategies need to be tailored to the communities that are affected. And so some government programs exist to help weatherize buildings, which of course reduces energy usage. Really important for people in under-resourced areas.
We're also seeing sustainable cooling strategies such as heat pumps and fans that are coming into play. And I think those are really, really important and will be in the future as well. And then I don't know if you've heard of this, but cooling pass, passive cooling such as night flushing where you flush the heat out of a building and allow the evening cool air to come in is also a strategy. And one that I've been reading about lately is cool roofs where roofs are being painted with a white paint that has a high albedo or reflectivity that will keep the houses cooler underneath.
It's a strategy that could be employed in much of the developing world as well because it's a very inexpensive strategy that I think has a lot of potential.
MONICA: Mary, let's now turn to something that you've already raised quite a few times during our conversation and which is absolutely critical. We know that there is an issue of underfunding in handling or addressing health issues internationally. In other words, international health efforts are drastically underfunded, especially in view of the amplification effects that climate change brings to the table, as you highlighted early on in our conversation. And particularly for diseases that are developing very rapidly. So one thing that came to my mind as I was thinking about things that we've discussed and things that we were talking about is M.pox. M.pox, previously known as monkeypox, erroneously, but now known as M.pox, M.pox is a disease that's been around for a while. The novel thing is the way that it's been affecting humans because it didn't affect humans as much in the past. Now it does. And yet we have a vaccine that presumably works relatively fairly well against this particular virus. And yet we've seen the spread of M-pox everywhere. We've seen cases in far-flung places and closer places and it's just spreading. And even though we've been through a pandemic very recently, only four years ago, yet we see this situation developing without much in the way of coordination or even thinking about or planning for and eventualities such as this one. How can we get more well-funded international health efforts out to address the needs of the population?
MARY: I think that we see the World Health Organization as a prime example of an organization that is attempting to ensure there's cooperation across countries when it comes to disease control, to alerting the populations about an emerging disease and to ensuring that there are whatever resources are available to help with the control of that disease. We also see our own Centers for Disease Control working abroad because in the recognition that anything that happens abroad can also move to the US because there is such global movement now, whether it's from trade or people moving around the globe. And so we need to be vigilant about all of these things.
And so there obviously is a need for enhanced funding for everything. We see the Pan American Health Organization working very closely with the US Centers for Disease Control and Prevention on diseases like dengue, like yellow fever outbreaks, things like this that could impact all of our populations, whether we're in the global north or the global south.
MONICA: Absolutely. So following up on that, one piece that I've been really interested in is the global governmental response to pandemic preparedness. And what do you think that governments would need to do to help ensure that we don't have another potential pandemic? Well, this is kind of impossible, but at least a potential pandemic that is very clearly going to come from climate change. What are we not doing?
MARY: So I think the number one factor is we need to enhance surveillance. And we have very limited surveillance, I'm going to say, in areas, for example, along the US-Mexico border. I mean, there is a border protection agency. There is a border infectious disease program. But there needs to be increased surveillance for all of these diseases. And there are labs that are funded by, for example, EcoHealth has a number of labs, I think 40 labs around the world where they're investigating emerging viruses. And it's really critical that we continue to fund these types of efforts to ensure that we are at least half a step ahead of what's coming down the pike.
And governments need to be prepared. What are the steps? You know, the current administration has established a pandemic preparedness group. And so they are working on developing this. But we also need to ensure that there is cooperation among countries. You know, we saw with COVID-19 that there were charges back and forth about whether or not we were seeing transparency when it came to the divulgence of all the issues around the virus. And so we need to ensure that scientific agencies are transparent with one another.
MONICA: So you've given us so much information, so much valuable information that I just have to ask you, what is it that you would really like everyone to know about climate change and health?
MARY: Yes. I think I'm going to just reiterate what I first started with, that climate change is not just affecting our physical health. Okay. I think it's really important for us to understand that we're seeing negative effects from on our mental health, on our spiritual health, and on our community health and wellbeing. And so we need to focus on strategies that are both adaptive and mitigative.
But we also need to focus on ensuring that all communities are involved in the decision making, that we are doing a top down as well as a bottom up approach to this. Because if we expect any of these efforts to be sustainable, we need to involve all communities from the outset.
MONICA: And in terms of, in your view, how important is it that perception shift from viewing climate change as a motivating factor for energy transition, which it is, as a carbon emission reduction necessity, which it also is, but how important do you think it is to have the public health aspect in there?
MARY: And I think we're starting to see that shift in our population now as we see more and more of these extreme events that are fueled by climate change. I think people are recognizing that public health is of the essence. If we don't have our health, we really don't have anything.
MONICA: Thank you for joining me on Policy for the Planet. Have a question or a topic to suggest? Email me at [email protected]. I'd love to hear from you.
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