Science in the Spotlight: Air quality, smoke, and the health impacts of wildfire

Welcome everyone to this NSF Encar Explorer series conversation. My name is Evan Portier and today we'll be talking about wildfires and how NSF ENCAR is working to provide solutions to this pressing environmental challenge. NSFAR, also known as the US National Science Foundation, National Center for Atmospheric Research, is a worldleading organization dedicated to understanding Earth's system science and how this science can help protect lives, support the economy, and strengthen communities and our national security. Suffice to say, the 2026 wildfire season has dominated headlines, not only in the United States, but around the world. For some regions, it's already been historic. As of two days ago, 142 new fires have been reported nationwide, including 12 new large fires. The impacts of these wildfires are being felt far beyond their burn zones, including widespread hazardous air quality due to wildfire smoke. to help us understand the intersection of wildfire smoke, air quality, and the impacts of human on human health. Uh we are joined today by NSF Encar scientist Forest Lacy. Forest, thank you so much for joining us today. Um you do such incredible work in this space and I want us to start off by if you can tell us a little bit about yourself and give us a highlevel overview of what you do here at NSFN car. Yeah, thanks Seven. Um I'm very happy to be here and and discuss this topic that I've worked on quite a bit. So um in general uh I do a lot of uh work on atmospheric models um particularly looking at air quality and how it impacts human health and other ecosystem impacts. Um so throughout my career uh both as a research scientist at CU and then um as a project scientist and postoc at ENCAR I've used atmospheric models to calculate how aerosols are emitted for and formed in the atmosphere and then look at how that how those aerosols and trace pollutants are then transported to where they have an effect on human populations. And I work with a lot of epidemiologists to understand uh kind of what are some of these unknown causes of uh disease pathways from air quality and things like that. And specifically on wildfires, I've been focused on quantifying uh using US health surveillance data to quantify how wildfires have impacted human health and if that impact is different than um particulate matter from other sources. >> Great. Thanks so much for that, Forest. Um, so kind of taking just a step back here and to give viewers and listeners just an understanding of what we're dealing with this year. Can you put this year's fire season in in context? Like what have you observed? Yeah, I think that um this year's fire season and probably kind of the last five years, five to 10 years have really ramped up in terms of magnitude of wildfires and in particular um the proximity of these wildfires to um urban populations or kind of what us as scientists at ENRA and other places refer to as the the wildland urban interface. And so what we're seeing is both an increase of those types of fires that are closer to populations. Um but then when we factor in the Canadian wildfires um and lots of the wildfires in Europe, we're also seeing a number of wildfire impacts uh that transport um down to regions that that don't often have as much of an impact. kind of in 2023 and this year uh the eastern seabboard we're seeing large impacts from fires up in Canada and Quebec where they're basically coming down from the north and affecting major metropolitan areas um along the Atlantic seabboard and so so that's something that happened in 2023 and is happening again this year and it's not something that has traditionally happened very much in the past especially for the kind of the summer fire So Forest, if I understand correctly, you're saying that we're seeing more of a prevalence of these wildfires breaking out in the wildfire urban interface, also known as the WOOI, and that these impacts are being felt far beyond spaces that they would normally typically historically seen. >> Yes, that's correct. So it's a combination of those two effects kind of that kind of 5 to 10 years that I talked about. That's where we've really seen an increase of wildfires in the wildland urban interface or or wooi. Um but kind of in the the two years that I mentioned the 2023 and this year um we're seeing significant burning activity um in Canada which then gets transported down uh the eastern seabboard and we're seeing impacts in places like New York or Washington uh DC and things like that. Um but that's not to be said that we don't see that all the time. And that's something that we've often had um in kind of western states. So, uh biomass burning from in British Columbia often impacts kind of the Rocky Mountain areas. And that's something that we do see is that southern transport from um Canadian wildfires and we're just seeing it in a a new area that's not often impacted. Um so when we're considering the the eastern seabboard there so kind of we put it uh put the wildfire season in this in this context here and so I want to kind of dive into the air quality aspect and so can you broadly explain how wildfires um influence air quality? >> Yeah, so there's a number of ways that wildfires actually impact air quality. So the first and probably the most known mechanism is anytime you burn bofuels um you create carbonatous aerosols either black carbon or organic carbon and this is lofted in the smoke plumes which then directly has an impact on human health. Um so we get emissions from just the act of burning. So particle emissions from the act of burning bofuels uh that then stay with the smoke as a kind of it rises and convective uh plumes throughout the atmosphere and then gets transported. In addition to the direct emissions of mostly carbonatous aerosols, we also see emissions of a number of gaseous species and those can go on uh either in the plume itself or when they mix with um urban influenced air to form other sources of aerosols. Um so we start to get some secondary organic aerosol formation not right at the emission source um but as the smoke plume is aged a little bit in the atmosphere. It also impacts other um species that we know have an impact on human health, particularly um NOx concentrations and ozone. So in areas downwind, we see impacts on ozone formation, especially as we start to mix with that nitrogenrich um urban air in kind of this biogenic dominated smoke plume. So, kind of just to recap that for us, it sounds like you're not only getting these these species, these particulates, these things in the air from the emissions, but also once they get into the atmosphere, they're interacting and producing kind of secondary compounds. Is that correct? >> Yeah, that's correct. So, we get the direct emissions just from the active burning. The act of burning also import uh emits a number of gaseous species um that we have measurements that we kind of take of as we burn different things we kind of take measurements and we understand what these gaseous pollutants are and that's something that ENCAR does a lot of along with other institutions and so we now have kind of this gaseous mix which we know interacts with other species in the atmosphere to form um secondary aerosols and then also impact ozone production. Great. So, it sounds like you have kind of like this complex almost soup of things that happen when you have these wildfires burning, but I want to kind of jump back real quickly because you mentioned something about biomass burning. And I think it'd be great to just give a little context of what you mean by biomass burning. And when we talk about wildfire smoke, we might not be talking about the wildland fires that we see in the news. >> Yeah. And so, um, I actually have a slide that might help it kind of visualize some of that. So, let me share that real quick. Um, but basically, so so this is now showing um this is now showing just just the US and and this is um basically showing the hours in which um you're exposed to some threshold of smoke exposure. And you can kind of see in the western United States, and this is from 2005 through 2018, if you're counting just for the hours exposed to wildfire smoke, um we see the typical pattern that we would expect to see in the western United States. Um we also see this signal in the southeast United States and that's coming from agricultural burning, uh where they also have wildfire burning and prescribed burning. So there's there's really kind of three regimes of smoke that are created um in kind of a typical environment. You have the wildland fires um which is what we see impacting basically in Canada and the western United States that then impact a very large area. We then have prescribed burning which is done um as part of forest management and usually done to kind of limit the magnitude of natural fires. And then also we do get smoke emissions from that that does get transported as well. And then kind of the third factor of um kind of wildland fires is is this burning of agricultural crop residue. And that typically happens seasonally both at the start and end of the harvesting season. And that's why we see kind of in this slide the the hours exposed um really increases in kind of the southeastern US. And and this is now showing kind of that same level of data where I've split it up into three regions where we see kind of the largest monthly average magnitude of uh smoke exposure which is this is now CO coming from smoke is in the western United States and kind of our typical biomass burning season. Um but we do see kind of these two peaks uh related to agricultural burning in the south and southeastern US where we're seeing a lot more of those agricultural burning. So each one of these contribute to um smoke and each one of those get transported to overpopulation centers and each one of them have have an impact and that's what we're working to kind of understand is what that impact is. >> Thanks for that. that really gives us um it's really surprising to me because I think you don't think you hear about that much in in our our news cycle about this biomass burning that happens in the east, but based on what you just showed us, it sounds very much that people in those population centers are exposed to wildfire smoke. Um and you're trying to discern what those impacts are. >> Yes, that's correct. So in that we've talked a little bit about the fire exposure or the the wildfire smoke exposure that folks are experiencing. So what exactly is it in wildfire smoke that is so harmful for human health? >> Yeah. So in general we know that there is um impact on human health from trace pollutants in the atmosphere. And the two that we know uh or the two or three that we know mostly impact human health are of highest impact is particulate matter uh of 2.5 microns in diameter or smaller. And the reason for that is PM2.5 when you breathe it in it's small enough that it goes into your lungs and has an impact on your your body's respiratory function. Um it can impact your oxygen uptake. It can impact how your heart functions. And so we know that um PM2.5 impacts human health. PM2.5 is a major constituent of uh biomass burning emissions. So we know that there's that direct exposure from that. In addition kind of we know that wildland fire smoke impacts ozone concentrations. Again, ozone replaces oxygen in the atmosphere. And basically, when you breathe that in, you're getting less oxygen, which we know again has has a human health impact. Not to the magnitude of PM2.5, but it does have a particular health impact. And then when we're talking particularly about wildland fire smoke or wildfire smoke, um there's been a number of studies that have shown that we have a differing impact from wildfire smoke or from biomass burning than we do from kind of uh just anthrogenic mixes of PM2.5. And so that's still an ongoing research question. Um, but kind of some of the preliminary studies have shown that wildfire smoke is more impactful than just PM2.5 by itself or just ozone by itself. And we're investigating some new pathways for um, disease outcomes and disease incidences. And so that's kind of in terms of the general health perspective. Um the other thing with wildfire smoke, particularly in regions that are heavily impacted, is that we know um large concentrations of PM2.5 or ozone have a particular impact on vulnerable populations. So um people with asthma, the very young or the very old. And so this is one of the few mechanisms particularly in the US where we get really high concentrations of particulate matter in the atmosphere. And so that really exacerbates a lot of these pre-existing conditions for vulnerable populations. And it's one of the few mechanisms that we often have that release releases PM2.5 in in those large concentrations of um 50 micrograms per meter cubed or above. And so um as we in the absence of other sources, this is having more and more of an impact. So there's also been a couple studies that have shown the contribution of wildfire smoke to overall air quality in the US has become more and more important. So we're seeing uh kind of as we see in general the reductions of PM2.5 from anthrogenic sources, we're seeing kind of a level amount of PM2.5 from wildfire smoke or increasing wildfire smoke. So it's becoming more and more important when we're looking at overall air quality at the general population level. So it's it's really interesting that you say that because it it sounds like we've made strides to reduce this per PM2.5 from those human or anthrop anthropogenic sources that you were mentioning. But in but in that reduction we've also experienced more wildfires, more smoke and so we're seeing more particulate matter PM2.5 being contributed from wildfire smoke. And then your active area of research is trying to understand those health impacts, right? >> Yes, that's correct. So we have um we basically we know that in general we've seen reductions in anthropogenic pollution kind of from 2000 to the present day. um due to different emissions uh control mechanisms um different policies that have been put in place particularly from the transportation sector and energy sector and so in general in the US we see um improving air quality and that's in the absence of wildfire activity if you have wildfire activity that basically remains flat or is increasing then the role of that on your annual average concentration becomes more important important and so that yes that's what we're seeing >> and so I'm I'm just curious here you have PM2.5 and you from wildfire how how do you go about understanding that that PM2.5 is from wildfire and not just from some [snorts] other source? Yeah. So that's that's a it's a pretty interesting research question and there's a couple different ways to do it and we have some of the ways that we do it here at ENCAR and other groups use other models. Um so the first way that we do this uh in my research is we basically take a tracer for wildfire smoke. we know how much wildfire smoke is emitted. Um and we use a tracer for CO uh which is has a known lifetime in the atmosphere and we basically say okay if we have CO um in wildfire smoke and then that gets transported it goes through atmospheric processing um that will basically follow the smoke plume to where uh the smoke parcel the smoke influence air parcel travels in the atmosphere. And so we use this tag tracer appro approach to say that okay this this tracer is emitted with wildfire smoke. It goes through the atmosphere. We know how much is emitted based on measurements of emissions factors. And then um we calculate that and and how that transports throughout the out the atmosphere. And then we look at okay what's the ratio of that tracer to total CO and that gives us a a rough estimate of the level of influence of wildfire smoke in a particular region at a particular time. Another way that this is done is by running two model simulations. One of them uh with wildfire smoke and one or one with wildfire emissions and one without wildfire emissions. And then there you can look at the difference between those two simulations and say, "Okay, well that gives you a a relative approximation for for what the wildfire uh influences." And then um there's other methods that uh look at particular tracers that are mostly emitted from kind of burning activity. So there's a couple of gaseous species um things like formaldahhide that are mainly emitted as a function of biomass burning and these are species that we can um observe using satellites in the atmosphere and from there we can get a rough estimation of what the wildfire smoke is as well and then kind of the if if we're only looking at kind of wildfire smoke exposure um Noah has a model um called high resolution rapid refresh smoke. Um, which again does a very similar thing uh to kind of this tag tracer approach except it's only focused on smoke and so it can run it uh with kind of a um reduced chemical mechanism or reduced atmospheric processing and it does it at very high resolution to understand how um those wildfire emissions are transported and spread throughout the atmosphere. So, those are just a couple methods of of what's being done to estimate the concentrations from wildfire smoke and distinguish that from uh other sources of pollution. Thanks for So, it sounds like we have kind of a decent handle by using these tracer methods to understand, you know, understand what is coming from or what is being emitted from wildfires. And so to kind of jump to this and I think it's a really important connection. Wildfired driven pollution is a term that is used right like it's a source wildfires are a source of pollutants. And so I kind of want to jump into this this big question here is what is our our current understanding of the impacts of wildfired driven pollution on human health? >> Yeah. So, so that is a again a a very good question and I'll kind of um let me pull up another slide real quick here. This is this is work that uh a colleague of ours um when Fuang has done. Um so so basically this is kind of showing um this is showing the impacts of all fires um but also focused on kind of WOOI fires. And so so what we have here is the the top panel is showing the ratio of WOOI fires um in uh the emissions in blue and the annual premature deaths in pink. And basically you can see that the the fraction of annual premature deaths is higher for all WOOI fires relative to all fires. Um and and so what this means is that we're seeing an excess amount of mortality due to these WOOI fires where um they're emitted and they affect a larger population. And and then the the bottom panel is now showing kind of all fires and this shows um kind of the the representation of kind of urban wooi and other fires uh relative to each other. So, so this is kind of our our current level of of understanding of of how um annual premature deaths are impacted by by wildfires. And then I think that there's been a number of other studies that have estimated um using kind of the same uh smoke exposure concentration functions and methods that we talked about earlier that show both national and global level contributions to premature death. And and it's in the order of um around 100,000 annual premature deaths in the US. And I don't know the numbers off the top of my head globally, but it it's much higher than that. And I think that the import one important thing to distinguish again here is that if especially if we're looking in a global context um it's very difficult to differentiate between wildland fire activity and biomass burning activity because the methods used to uh observe those from space which is usually kind of satellite observations of um fire radiative power or burned area um those don't necessarily differentiate between if it's a wildland fire or if it's an agricultural fire or um a prescribed burn. And so you have to use additional methods to identify what is the contribution purely from wildland fire activity versus agricultural burning. and particularly in other parts of the of the world. Um in India we see so for example in India and large parts of Africa we see seasonal patterns of agricultural burning that impact huge populations and so the the research question is is that a it's obviously um air quality due to smoke exposure but what do we lump that into? Do we lump that into wildland fire activity or prescribed burning or do we just have kind of a proxy for total burning emissions? And so I think that's what the current level of research is looking into is are there particular types of burning that are more impactful on human health than others? And I I hope that kind of gets at the question you were asking. Um but if not, you need clarification. Go ahead. Well, that I mean that's real that's such an interesting piece of information here that there's these different types of wildfires like you were talking about biomass or agriculture or wildland fires. the ones that we think about are forest fires or prescribed burns you think and it's sounding like the direction of the field is trying to like disentangle like what are the specific impacts from each type of these fires which I think again going back to what the the headlines are dominated is that you see a lot of these wildland fires but we don't aren't considering kind of this biomass burning or or prescribed burning um effects on our health. So, and then and then just another note too, when we're talking about health impacts, can you just talk a little bit about there is something like acute exposure versus long-term exposure and how that kind of fits into all of this? >> Yeah, and that's that's an area of research that I've been um really focused on um lately. And again, I think I have two slides that kind of show this. Um so so if we're if we're interested in smoke exposure um we basically have uh a fire event and depending on if you're near the region or if it's transported smoke um oftent times if in near source regions we have a relatively quick exposure period um that's active while the fire is active um but where we're seeing kind of the exposure um from transported smoke plumes um particularly from Canada and kind of boreal fires up there um that often has kind of an extended exposure pattern and so most of the health impacts that we're talking about looking at premature deaths um are focused on kind of chronic exposure or annual average metrics. And so right now the field is working towards calculating some some new metrics particular to wildfires. Um and some that that I've been working with are um years expo or uh hours exposed per year um or uh the mean expo mean concentrations during wildfire events. So obviously you have kind of some baseline level of exposure that you deal with every day. During wildfire events that's elevated. So looking at that delta um can give you some particular health information. And then kind of the integrated exposure throughout the year is another metric because that tells you if you're in a near source region like obviously you have this really large spike of exposure and that um can tend to lead to exacerbations of other health impacts. So the chronic impacts usually deal with kind of annual average concentrations or concentrations during a fire season. Um but when we start talking about acute effects that is where we are more looking at um vulnerable populations and kind of acute um occurrences. So things like hospitalizations um prescription fills for inhalers and things like that. All of those may be driven not necessarily or may not be seen when we look at annual average concentrations, but instead are seen if we look at these kind of short events. And so this is some work that Rebecca Boltz has done in ACOM where um there were two different fires in kind of Sonoma County and we had a lowcost sensor set up and here you can kind of see these spikes dealing with um kind of hourly PM 2.5. So we know that there's a DAO pattern to PM2.5. It kind of uh compresses as as a function of the the planetary boundary layer. But here we're seeing these spikes um at the unhealthy level. And then this one lasts for several days for this particular fire event. And then here in in the glass agricultural pass region again we see these spikes um as a function of of wildfire activity. And um again in in in another uh study in California, this one up in Santa Rosa, um we had both indoor and outdoor um sensors. And here now uh we we did some filtering for times above a certain wildfire threshold using our CO fire tracer. And here between all three of the sensors and the model data, we're seeing a statistical increase in kind of the mean PM2.5 concentrations both outdoor and in the built environment. And so so this really tells us that um wildfire one we see an increase in um in PM 2.5 concentrations during wildfire periods which is kind of a well-known um fact. Um but we are seeing those same statistical increases uh in the built environment as well. So you do get infiltration into the home and and this is something that um uh several groups at CU have looked at quite a bit is once it gets into the home it tends to remain there and you kind of get remission of wildfire sources for an extended period of time. Um, so two groups did uh studies based off the Marshall fire that showed that once wildfire smoke entered the built environment, it was very difficult to remove and you would get reemissions and kind of trace wildfire um pollutant tracers six to six months to a year after the wildfire event. So, so that's something else that we don't really consider when we're looking at these kind of epidemiological studies focused on annual average concentrations, but we know we do have um an impact in uh particularly from from fires in in the WOOI. And Forest, kind of just going off that note, is is it that we just my understanding is most of our observations are are outdoors. you have outdoor sensors and so that's kind of how we might be in the past calculating some of these these metrics but what you're saying is that that the smoke is infiltrating into our built environment and that also has health ramifications. >> Yeah. Yeah. I think that that's that's a key point to make is that anytime we have excessive amounts of pollution in uh in a in a region or in an area so um over Denver as a function of uh kind of wildfires either nearby or transported um that level of pollution does go into the built environment and then we we do see remission of that in the built environment which then can lead to health impacts further. down the road and that's not something we typically account for in our kind of regional or global health studies. So we established that wildfired driven pollution is a thing to be concerned about. There's this PM2.5 that is well established that when you have these wildfires they emit PM2.5 and other things like ozone. And so how exactly is the work that you're doing here at NSF Encar helping helping us understand have better understanding of this? Yeah. So um the work that I'm doing and other scientists at ENCAR are really approaching wildfires from from a number of different aspects. Um and so I kind of like to think of it in about three different stages. So when we're talking about a wildfire, we can start at kind of the most basic stage, which is fire process level. And so so we have scientists that are measuring emissions factors from certain materials or from um certain environments and these can then get transferred into the models. So like right now if we're looking at a regional or a global model um we have around 17 different kind of plat functional types that we if we know that there's burning there we know what the emissions from that type of uh environment is on kind of a per kilogram basis. And so there's definitely some improvements to that as especially as we go into WOOI fires because one of those um kind of types of land cover um can be urban and right now we're not currently accounting for the emissions from structures in the model. And we know that um many different pollutants are emitted from when you burn a barn versus when you burn uh a tree. And so that's something that we need to account for in these models and that's something that um ENCAR scientists are doing. And then again at the process level um something that uh we're doing particularly in RA is okay if we see that there's an emissions event um how does that move throughout the land or how where is it getting its fuel from and so so we've developed a lot of data sets for kind of fuel moisture content and then also a community fire behavior model where we're now estimating okay if we have an ignition event um how Does that develop into a wildfire? And by taking kind of really high resolution fuel moisture content data and using the community fire behavior model that has high resolution meteorology, we're able to better estimate the spread and kind of the boundaries of these these wildfires at at really high scales. And so both of those things are what I consider to be process level um improvements that we're trying to make. And through those we can translate some of that into um regional level model simulations. So uh we are developing improved parameterizations for what the emissions are. Um improved emissions inventories that we can then put into our model and have a better understanding of what the concentrations are for different pollutants. um be that PM2.5 or be that some of these gaseous species that go on to form PM2.5. And so that's kind of at the regional level. And then um also at the regional level where we have a lot of collaboration uh both with the CDC and other epidemiologists is in linking this exposures to tangible health outcomes. And so I I talked a little bit about uh previously about hospitalizations and prescription fills. Those are both metrics that we're looking at from the lens of these new wildfire smoke exposure metrics and we're trying to develop a relationship between okay, how how manyos excess hospitalizations do we get during um wildfire events? And that's that would be an improvement because then that helps um city managers or uh different policy standpoints from different policy standpoints to estimate. All right, we know that we're getting wildfire exposure seasonally. Um and we know that this puts this excess strain on our health care system. How do we prepare for that? um because we know that there's typically a biomass burning season uh through the summer months and we know that there's um additional impacts from wildfires and we know that there will be additional hospitalizations that helps epidemiologists better prepare and then I think from other research that ENCAR is doing that I'm not as involved in is looking forward so into the future and estimating okay well how is the wildfire landscape changing and there's done a lot of of work with our our kind of high resolution long-term uh chemistry climate models to understand. All right, how are these these different indices that measure um fire activity, how are these changing as we move to 2050 or as we move to the end of the century or how does the increase of the wildland urban interface, how does that impact the population impacted by smoke? And so that's a lot of really valuable research that um scientists at ENAR are doing to better understand and contextualize wildland fire activity in in kind of this changing environment. >> Great. I feel like there's there's a lot to unpack there, but I want to go back to the first thing you were saying about the process level work that's being done and you mentioned emission factors. Is it can you expand a bit like what do you mean by emission factors and what is like our current understanding? How do we go about understanding emission factors and why are they important for models? >> Yeah. So um at at Encar we have uh Finn which is the the fire fire inventory from ENCAR. Um and what that does is that takes satellite observations of um kind of burning activity at basically at kind of a 375 meter resolution globally. And we know that okay we had we had a fire here. We know the FRP which is the fire radiative power. Um so that gives a level or a measure of the intensity of fire activity. And so this model takes that data along with land cover data and says, "All right, we know that this 375 meter grid cell um has temperate forest." And from studies where basically they take um kind of temperate forest residue and burn it in a lab and they understand what the emissions are um due from complex measurements of what species are come out when you burn 1 kilogram of temperate forest or what emissions come out if you burn 1 kilogram of grassland. And so so the the inventory model takes those measurements and calculates how much emissions of different trace pollutants are and then that goes into our regional models. So that's what the emission factors are. The emission factors are representations of if you burn 1 kilogram of fuel, what comes out of it? How much CO2 comes out? How much CO comes out? How much black carbon organic carbon? And so those are the emissions factors. Where we're limited in our knowledge is how much of these how complex can we get with these emissions factors. Um both from there's there's hundreds of different species that are emitted. Um but which ones of those can we put into our model and then also there's hundreds of different types of materials that can be burned and different levels of moisture on the ground. And so all of those will impact what those emissions factors are. And kind of if you think about the the combinations of all of this, it becomes really really large. So so we have to parameterize it. And what that means is basically we take a a rough estimation of all right well this study said that 1 kilogram of temperate forest emits five grams of black carbon. This study says it emits 15. Okay, we can kind of take an average from that. Um, but those might have different conditions that lead to that uh emissions discrepancy and that's not something that we take into account in our global models. So, there's definitely improvements that can be made there. Um, and I think particularly when we're considering structure fires and fires near the the built environment. So things like the Paradise Fire, obviously that had a number of structures impacted and um emissions from that would be very very different than if we burned um kind of a forested area outside of Los Angeles. And and so that's not something that we typically account for in the model itself. Um but I think that we do need to account for moving forward. Yeah, I mean I think it's just that really good to highlight is that things burn differently like structures burn differently, the different land covers burn differently and that all influences and affects um this wildfired driven pollution. So we've we've talked about some of the work that you're doing here and I think one aspect that's really interesting um to me at least is just like the collaborative nature. you said you've had some collaborations with the CDC and I'm just wondering if you can expand upon this concept of what we call team science and the collaborators you do work with and and Yeah. Yeah. So, um I I think to me that's kind of the most satisfying part about science is developing these collaborations and looking at uh new and novel things that I'm not able to look at on my own. So, um, particularly the one project is with the CDC, um, and that we've basically now taken a a 20-year, um, representation of wildfire smoke exposure and looked at that with respect to a number of different health outcomes. and we're calculating okay what is the relationship between um different wildfire exposure metrics and hospitalizations or prescription bills or um kind of mortality from different disease outcomes. So, so that's something that me as an atmospheric scientist, um, I don't have the capability to run these statistical models that are needed to determine kind of social outcomes. And so I rely on scientists at the CDC to do that. Other projects um, include some where we're collaborating with NYU and and this is kind of that indooroutdoor um, observations that we took in in Santa Rosa. um in for that particular study, we're looking at wildfire implants, wildfire impacts on kind of functional aging. And what we're doing for that is that's not really kind of a standard health outcome that you um have a lot of data on. So to develop those health responses, we actually took and surveyed a large cohort in California um about okay what was their uh perception of wildfire and then how did they feel during and after events. Um there were some mental faculty testing and things like that that we did along with some biomarkers. And so so all of that um is again something that I have to rely on other scientists to to develop these surveys and to develop these these linkages between the metrics that we have for exposure and and what that means from kind of a health science. And then um kind of in a a similar study, we've we've taken uh data for Denver and uh collaborated with a psychologist at Denver University to see how um wildfire and and wildfire events and these smoke concentrations impact mental health. And so all of these are things that are outside of the realm of what you would typically be working on as an atmospheric scientist. and just it it's really nice to develop those kind of teams that can study that type of uh outcomes and and work towards that. >> Yeah, that's that's such fascinating work and and I will continue to follow you and the work that you do because that sounds just like something that is on a lot of people's minds is not only the physical health impacts from wildfires but that mental aspect as well. First, um, we're going to open it up to Q&A and to give folks a little bit of time to think about questions. This is your time to type in questions into the Slido platform. If you scroll down, you'll be able to see uh the place where you input. Um, but before we jump into Q&As's, I would like to show you all just some of our future events that are coming up. Um, most importantly and or most topically related is we have a forecasting wildfire behavior. That's going to be another virtual session with Jason Conneal at on August 25th, 11 to 12:00 pm Mountain time. If there are folks online that are local to Boulder County or the Denver metro area, we have two in-person events. Uh, one focused on keeping space safe and understanding the impacts of space weather on satellite orbits. That's happening the next day on August 26th at the Frasier uh, community. And then August 29th, we have from models to forecast tools for better water operations. We will have uh joint representatives from both NSF ENCAR and the Bureau of Reclamation talking about the Big uh Thompson River and that will happen at the Loveland Museum. If you are online and you are not local to uh to the Boulder County or Denver metro area, we have do have another virtual or I should say hybrid event happening on September 2nd titled CloudMakers: How Alaska Seasons Paint the Sky. really interesting talk about how uh we use cruise ships to really understand um aerosol for aerosols and how weather is formed out on sea. I also will preface to folks if you want you can take a screenshot of this you can also visit our website you can just type in NSFAR explorer series you'll find all these details about these events. Lastly there is a QR code right here that really helps us um out. It's an evaluation survey telling us how you felt about this event. Um, please, if you have the chance to fill that out, that would be great. We do use this for educational research. Really helps us promote science outreach and keep these events going. So, if you can scan that code and with that, we'll kind of jump into some questions here. Let's see here. And as they as they come in, Forest, I do want to ask you, what are some really I guess um what directions do you see your own personal research taking um in the future? Yeah. What questions are getting you excited? Yeah, I think that one question that we're we're really trying to study um that we just haven't had the opportunity to yet is what happens when we have known health um impacting variables. Uh so for example, extreme heat and wildfire smoke. If we have both of those at the same time, what is the impact of that on human health? Is it additive? Are they compounding? Or is it somewhere in between? And and so I think that's probably one of the biggest questions that I would like to study moving forward is compound hazards, how do they impact human health? And then I think um the the second question that that I'd be interested in exploring in even more detail is uh kind of expanding on the work with the CDC where we're looking at kind of new exposure response functions for for wildfire activity. Um I'd like to differentiate that between these kind of three regimes of burning that we talked about earlier. So, does wildfire or wildland fire smoke have the same impact as agricultural fires or prescribed burning? And if they have differing impacts, um, what can we do from kind of a prescribed burning or a forest management standpoint to really reduce the health outcomes from wildland fire activity and and is there is that something that we have an opportunity to do moving forward? So I think that those are probably the two biggest research questions that I would like to explore moving forward in this space. Both the compound hazards and then also um kind of [snorts] smoke regime or burning regime influence on on health outcomes. Yeah, that compound health impacts is a really interesting one because it seems and I don't have anything to support this, but it seems like with this summer at least here in in this region, we've been experiencing a heat wave, but also compounded with wildfire smoke. So, really interesting questions there. I want to kind of jump back to some of the research that ENCAR does as a whole and we didn't really talk about instrumentation that much. We alluded to our satellites, but I'm wondering if you could just touch a bit of on like some of the satellite um or some of the instrumentation that we do here at NSFAR. Yeah, from from an instrumentation standpoint, um one we have uh several researchers that are focused on kind of those process level um emission factors. So better quantifying what emissions are from um different species or from different land types or different plant types. and and so um we've worked a lot on quantifying those emissions factors and incorporating them into this huge emissions database that we then can um then can add into models and and so so that's one type of measurements we do. The other type of measurement that we do and that has really been impactful in the past um was with our airborne campaigns. So both in WAN and FireX um our airborne instruments did a really really good job um evaluating uh smoke plumes and what their composition was. And so what that really informs us is how smoke plumes age. Kind of what chemistry is going on in those smoke plumes because we have really high resolution data both from a species standpoint and from a temporal standpoint um for different fire events uh that were part of both fireex and wean. And um I think that both of those types of instrumentations are are really important in in modeling uh basically what wildland fire smoke is made up of. Oh, I think you're muted. Thanks. We do have a couple of questions here from our from our audience. Uh first one is is there any research that focuses on wildland firefighters health while engaged in suppression efforts? >> Yes. So um there is some research I would say particularly at ENCAR what we're doing to to help with that is um this community fire behavior model um that better estimates kind of the spread of wildfires in kind of near realtime situations. So that gives um us a better understanding based on kind of high resolution meteorology what the fire is going to do. So we're able to better predict um kind of what shifts will if shifts happen from meteorology or from kind of a fire weather standpoint uh what's what's a good way to to protect firefighters from kind of shifting winds and things like that or what would happen when wind shift. Um, in terms of smoke exposure for wildland fires, that's not something that, uh, we've done a lot of research on or that has, um, actually has a ton of research on itself. Um, but it is definitely an avenue that I know kind of the Bureau of Land Management is considering for um, and NASA has considered in some of their funding calls over the past couple years. >> Great. We do have another question here. um related to this just observations in general. Why does it seem that visual air smokiness does not seem to correlate with PM2.5 measurements? For example, today in Boulder, the air has been 30 to 40s AQI, which is green for PM2.5, but when I look at the mountains, they still look cloudy or smoky. Other days, it seems to be the opposite. >> Yeah. And some of that has to do with with atmospheric dynamics. Um, so when we're looking at AQI, that's a measurement of near surface pollutant concentrations. Um, and when we're looking up at the sky, that could be due to, um, we basically have a smoke plume traveling over kind of the Boulder Denver metro area. Um, so it's not impacting the near surface smoke concentrations. Um, and then also kind of the level of cloudiness is also a function of gaseous pollutants which don't contribute to PM2.5. So kind of the the haze that we see in Denver sometime during ozone alert days um that's actually due to ozone which is a gaseous pollutant and is a separate metric when evaluating AQI. So kind of for those two reasons um that's what we see and then also um the AQI the near surface representation of AQI from kind of air now and the EPA systems um doesn't always account for uh kind of real-time shifts in weather patterns. So it may not be updated based on shifting winds that we get. We know we get a lot of um kind of complex meteorology in the front range particularly coming uh mixing air and coming down the front range and so that is not always caught kind of in the forecast systems that are used in air now. And so so that may be we're basically just missing kind of this smoke influence that uh in air now that we are seeing from kind of a physical standpoint. And you can always check the um kind of the observation sites themselves and see what they read. Um either you can check like purple air, they have lowcost sensor data. Um Denver operates the love my air network which is really nice uh observation set and and see what kind of nearrealtime measurements are on a neighborhood by neighborhood level. >> Great. We have time for just one more question and I think this is the active area of research you were talking about, but what are the differences in health effects between the southeast the biomass burning fires you were alluding to versus the western um or the wildland fires. >> Yeah. And and that's that's kind of my my ongoing source of research right now is really focused on differentiating that because if if you look at um kind of the the magnitude of uh smoke exposure that you get if you look at it from kind of a PM2.5 or um from a concentration dose function um you get much higher levels of smoke from these these wildland fires. Um, but you get more consistent exposure from kind of seasonal agricultural burning. It basically lasts for for weeks at a time. And so it's lower dose but higher temporal duration. Whereas from wildland fires, you basically get kind of a high dose for a oneweek period and then it drops off. Um, then maybe you get another wildfire influence. It's another high dose and then drops off again. And so that's what we're really trying to tease out is what are those differences in health impacts from uh different smoke exposure regimes. Great. So for this question, I encourage folks to continue following ENCAR and UKAR um as we have more exciting results down the pipeline from Forest and his colleagues. Uh Forest, I want to thank you so much for this conversation. I know there's a couple more questions from the audience. If you still would like to ask these questions, you feel free to email us and we will get these questions to Forest. For Boris, again, thank you so much. Uh folks that are online, again, just another plug for our evaluation survey. If you can fill that out, that would be great. And it really helps us improve these events. You can scan the QR code right there or take a screenshot. But again, thank you everyone for joining today and hopefully see you on the next event.