 All right, go ahead and get started. Good afternoon, everybody. My name is Megan Levy. I am a media officer with the National Academy's Office of News and Public Information. Thank you for joining us today for a webinar on the report that was released last week titled the chemistry of fires at the wildland urban interface. You can now download a copy of the report and other supporting materials including an interactive document. You can find it at www.nap.edu and we'll also chat that link out to you. A recording of this webinar will be available on the National Academy's website in the coming weeks as well. For those of you who are not familiar with the US National Academies of Sciences, Engineering and Medicine, we are private nonprofit institutions that provide independent objective analysis and advice to the US to solve complex problems and inform public policy decisions related to science technology and medicine. For each requested study, panel members are chosen for their expertise and experience and they serve pro bono to carry out the study statement of task. The reports that result from the study represent the consensus view of the committee and must undergo external peer review before they're released as did this report. Before I introduce a few members of the committee that are joining us today. I'll just go over a few quick reminders. The webinar is scheduled to last one hour so we'll start with a presentation and then after the presentation is finished we'll open it up to any questions that the audience may have. To ask a question just click the Q&A button at the bottom of your screen and type it in and you can ask a question and submit it at any time during the presentation. All right so now I'd like to introduce some members of the committee that wrote the report who are joining us today. I'm with Dave Allen, Chair of the committee and Melvin H. Gertz, Regents Professor of Chemical Engineering and the director of the Center for Energy and Environmental Resources at the University of Texas at Boston. We have Femi Aditona, Associate Professor in the College of Public Health at the Ohio State University. I'm a research mechanical engineer with the US Environmental Protection Agency's Office of Research and Development. Fernando Rosario Ortiz, Professor of Environmental Engineering at the University of Colorado Boulder, and Barbara Turpin, Professor and Chair of the Department of Environmental Sciences and Engineering at the University of North Carolina at Chapel Hill. And so with that I will turn it over to the chair, Dr. Allen. And thanks for your interest in this report that was released last week by the National Academies, the Chemistry of Fires at the Wildland Urban Interface. I'm going to take about 15 or 20 minutes to give you a high level overview of the report, and then we'll be available to answer your questions. We can go to the next slide. The study sponsors were the Centers for Disease Control and Prevention, the NIEHS, the National Institute for Environmental Health Sciences, National Institute of Standards and Technology, NIST, and then also there were internal Academy funds provided for this work. Next slide. As with all Academy studies, our study was guided by a statement of task and we were responsive to that statement of task. The statement of task that we were given is reproduced here, I'm not going to read this to you, but we've highlighted in bold a couple of key elements that will guide the rest of the presentation. First, we were asked to describe chemistry information that would improve the mitigation of acute and long-term health effects associated with fires occurring at the Wildland Urban Interface, WUI, the Wildland Urban Interface, and WUI as I'll likely be saying throughout the presentation. Recognizing that there may be knowledge gaps, our statement of task also then directed us to describe opportunities for research to fill key decision gaps or critical information gaps that could aid decision makers that are charged with addressing the impacts of WUI fires. That was our statement of task. Next slide. We had a diverse roster of committee members giving us multiple perspectives on WUI fires ranging from the fuels that are combusted to the combustion conditions and the combustion chemistry to the transport and transformation of emissions and from WUI fires in media to health effects. And so this is the group of volunteers who prepared this report all again, as I've done multiple times, express my thanks to this great committee. It was a pleasure working with all of them to produce this report. Next slide. Let me then just jump in and summarize some of the main messages and recommendations from the report. And let's start with the next slide and the first message, which is that the extent of the Wildland Urban Interface is increasing. The incidence of fires at the WUI is increasing and these trends are pervasive throughout the United States. There are some 40 million homes that exist at the Wildland Urban Interface. And certainly one of the things I learned in this study is that the Wildland Urban Interface is not strictly a Western phenomenon. We hear a lot of coverage in the news about Western fires, which tend to be larger than fires in the East. But we have interfaces between vegetation and urban structures, residences throughout the United States. And what you see to the right is a mapping of some of these WUI fires. In the Western U.S., these tend to be interface communities. In other words, an urban area abutting against large vegetated areas. In contrast in the Eastern U.S., it tends to be intermixed wildland and urban areas. Nevertheless, those interfaces between the urban areas and the Wildland areas exist throughout the U.S. And it's a very rapidly growing land type. And for a variety of reasons, the vulnerability is increasing due to climate change, due to effects like drought and heat, due to fire and land management practices, other factors that are increasing the extent and also the hazards associated with WUI communities to fires. Next slide. Another main message of the report is that WUI fires are different. Different than wildland fires, different than urban fires. And those differences are multiple. So there are differences in the composition of the fuels. So the mix of vegetation and urban structures gives us a unique contribution and composition of fuels that might burn when the interface between wildland and urban areas burn. In addition, there are differences in fuel loadings. The amount of fuel per acre or per square kilometer can be quite different in a WUI at that interface than it is in a wildland or that it is in an urban area. The combustion conditions are different and the reasons for this are multiple, but let me give you a simple illustration of this by comparing the way in which a structure burns typically in an urban fire, as opposed to a WUI fire. In an urban fire, typically the ignition source is within the structure and the structure will essentially burn from the inside out with resulting amounts of oxygen to feed the fire available with the resulting temperature and a volatilization of fuels. In contrast, a WUI fire often is ignited from outside the structure and so the structure burns from the outside in and therefore the combustion characteristics can be dramatically different than strictly a structural fire. And so there are differences in combustion conditions that lead to differences in what the emissions are. So those differences in fuels, the fuel loadings, the combustion conditions lead to differences of emissions. Those differences in emissions then result in species that undergo different chemistries is that fire plume can be transported hundreds to thousands of kilometers. And so the atmospheric transport and transformation is different. The residues and affluence of the fire are different, resulting in quite different environmental chemistries and therefore exposures and health effects can be different. So the WUI is different in multiple ways than strictly a wildland fire or an urban fire. The main message of the report is that our direct knowledge of WUI fires and emissions and their health effects is largely based on extrapolations and inferences from what we know about wildland fires and what we know about urban fires. We can project and infer what the chemistries might be, what the combustion conditions and emissions might be, but there is a paucity of direct data, direct data that are available on the WUI are quite sparse. And that's because what we're interested in to understand fires at the WUI is that interface, which by definition is a pretty restrictive area. It's the burning that's occurring right at that interface, not over the entire fire. So that makes the data scarce. It also makes the data hard to get because you need to be at those interfaces. And so there are challenges associated with getting measurements of fires and their emissions at the wildland urban interface. But there are also opportunities. There are great many advances in measurement science that have been made in order to miniaturize equipment and to achieve other types of advances in measurements. And we have now new capabilities that can allow us to begin to collect measurements at these interfaces, although it will be challenging. Next slide. So what the committee did was to identify major research needs throughout this system of going from sources of emissions to health impacts and to identify research needs and knowledge gaps that need to be filled in a variety of categories. The categories that we identified and listed research needs in included the fuels and emissions, transport and transformation of those emissions and effluence, and then the exposure and health. We also identified the need for new measurements. And in each of these areas, we noted that there was a need for fundamental measurements or field and population studies, and for the development of new predictive tools. And so what we tried to do was to summarize these research needs at varying levels of detail throughout the report. And the way we did this in the report summary that hopefully many of you will read was to create a table that I'll go to in just a minute. We also had had as its columns these areas of research need the fuels and emissions the transport and transformation, exposure and health, the new measurements, as well as rose that consisted of these various categories of research fundamental measurements field and population studies and the development of predicted tools. We noted that this research should be coordinated. We need to develop stakeholder teams and research teams that will tie all of this information together because after all, what gets emitted will influence what the atmospheric chemistry and the atmosphere transformations, and the other transformations will be. It will affect the exposures and the health impacts, and that in turn will determine who the at risk communities are so all of these research activities would be most useful if coordinated. So let's go to the next slide and identify some of the near term research priorities that the committee identified there is a table that appears in the main report that lists all of those research needs and the categories that I identified, but the committee recognized that we should identify what we regarded as a committee as high profile research needs, and we identified three. The first is to begin to better understand the chemical composition of the materials and structures at risk from we fire so what are the things that might burn at the interface. They can be highly varied communities very tremendously across the United States at the wui and what materials make up structures of the wui as well as the vegetation loading varies dramatically from region to region. So this is the starting point, we don't know what might be the fuel, then we're going to have a very hard time predicting what the emissions are what the transport chemistry, what the effluence might be what the exposures and health impacts might be so a key enabling set of systems would be to get much better definition on the compositions of the potential fuels at wui fires. Another thing that can be done quite readily and quite quickly would be to add measurements of targeted wui toxicants to air and water quality monitoring systems throughout the country and these may be permanent installations or they may be deployable to areas that experience fires at the wildland urban interface, but measuring what actually comes off of wui fires will also bound our knowledge and bound the scope of much of the rest of the problem about what might happen what chemistries might be important if we can look at and identify what those wui toxicants are so the committee identified these two bookends of research needs. Then finally, we noted that much of the information about movies as we went through our work was scattered and disconnected. And so there's a real need to facilitate information transfer across all these diverse communities that can make contributions to a better understanding of wui fires and so we also suggested as a high priority that information repositories be established to help the exchange of information. Next slide. So, based on all that the committee made two recommendations. One is that various agencies associated with funding research should implement the multidisciplinary research agenda that is identified in the report. And that agencies funding and the investigators doing the research should coordinate their research plans and activities and contribute to these repositories of information that will facilitate exchange of research information. The second thing that and a second recommendation is that as a part of these research activities. The project should have deliverables that really address the needs of actionable decision making for decision makers working with the at risk communities and vulnerable populations we can make a lot of progress in research. But we also need to get information to decision makers who are addressing wui fires on a day to day basis. And so we also suggest that this be made a part of these research programs to develop these actionable activities aimed at decision makers. Next slide. So, there's a lot of detail in the report. And it's a fairly lengthy report but the summary is a good overview of it. So, there's a lot of detail in the report about specific areas and specific research needs so that includes the fuels. So the materials, the combustion and the emissions associated with wui fires, how they are transformed in the atmosphere, how they can wind up in water and soil, what the human exposures and health impacts might be. What some of the mitigation possibilities might be. And then finally, how do we go about improving our measurements and so that together with a final summary chapter in the summary, which collects all of that information provides a good overview of where the committee identified information gaps. Next slide. So if you want to get the report, you can click on these images at once again like to thank the sponsors of the report and the committee for all their hard work on this and at this point, we'll open it up for questions. And again, the process will be that you would enter any questions that you have in the Q&A. Megan will read those off. I'll be the initial recipient of the questions that may redirect them to committee members who are present here today, who may have more expertise in the area than I do of your question. So, Megan, do you have questions for us? I do, I do indeed. Thank you for that presentation. Our very first question. I'm getting some feedback. I'm not sure. Okay, I think it's gone. Thank you. Our first question today is, what may be the differences in emissions between structure fires and wui fires. Is it mainly a difference in scale and extensive burning with wui fires being larger. And so there can be multiple differences associated with strictly structure fires and wui fires. And so, and the differences between a structure fire and a wui fire are going to be a little bit more subtle than the differences between wildland fires and wui fires and so I think I'm interpreting the question properly is to emphasize these differences in structure fires and wui fires and so I'll highlight one difference that goes back to things that I stated a little bit earlier and then I'll turn to Amara, who was a principal who has expertise in this area and the differences in emissions. And one of the things that I mentioned earlier as I was going through the slides is the combustion conditions can be what quite different. So typically in a structure fire. Your ignition source might be within the structure, and as a consequence, the way that the fire will develop and therefore the temperature history of the production of the emissions is going to be dependent on the amount of available oxygen that you have inside that structure. In contrast, in a typical wui fire. You might have a lot more oxygen available in those initial phases of the of the structure burning, leading to quite different types of emission products from the combustion Amara, do you have anything to add to that. Sure, some other differences that the oxygen content I just want to say is really critical here in a situation in a structure fire when the oxygen concentration is low that skews the emission products into products of incomplete combustion. So you're going to have a lot more carbon monoxide and hydrocarbons in particular matter being emitted under these conditions. So looking at a wui fire where you might be burning from the outside in the oxygen concentration may initially start up high but then as a fire progresses in inside the structure you may see more of these structure fire conditions. Another major difference is that in structure fires you might have only one or two rooms participate in the fire and the fire may be really burning through some of the interior furnishings. So it might be a couch or a cabinet or other interior furnishings that are really the fuel that's being burned there before the fire gets suppressed. Whereas in a wui fire you'll have participation of the entire structure itself so it will spread from the wood framing of the fire into inside and it will have the furnishings the clothing chemicals. The home might be included in the burn so you'd have pesticides or paints and other compounds like that you might even have fixtures that are going to be burned as well. So there's some key differences there and then one final difference I'd like to touch on is the difference of the external environment and so many of these wui fires we found occurred during high wind events so you'd have some strong winds surrounding that would be impacting the combustion conditions as well and so that might also skew, whether it's going to be more of a flaming or smoldering or how much oxygen content is available to impact the emissions that are being produced. All right, thank you very much. Our next question is, does the report offer any recommendations for what water utilities should do before an after a wui fire. The report speaks to that quite extensively and I'm just going to turn to Fernando on this one. The report covers the information available on what are the potential risks to a water community water system after a wui fire. You know we talked about some of the potential contamination issues with organic contaminants with metals. On the scope of the report there are other materials that are having published already by different groups that touch upon some of the things that utilities can do preemptively to be ready for this type of event. I will also stress that one of the, as Dave mentioned in his remarks, one of the difficulties that we have is there's, there's still some data gaps that are out there, and research needs associated with, for example, how long will some of these contamination events may be like what will be the extent of the contamination. Some information that we will need to know before we can make a specific recommendation for utilities on how to safeguard their systems after, after a fire. Having said that there's a lot that we do know, including the report and other materials and feel free to contact me if you have any further questions. Great, thank you very much. Our next question is, have you looked into how invasive plant species can play a role in wui fires. You know the report touches on on a variety of different types of fires and uses a number of different types of fires as examples and wui fires can be dramatically different in the type of vegetation that's burning. We're using two examples that appear in the report comparing, for example, the campfire in California versus the Marshall fire in Colorado, which had very different types of vegetation associated with them. But that they can be dramatically different. We did not specifically address invasive species and their potential for for setting up wui fires or increasing the hazard of wui fires or changing the combustion chemistry. Okay, great, thank you. I'll be able to determine if the health risks of firefighters operating in the wui are similar to those when firefighters are fighting a traditional structure fire. And do the committee draw any conclusions about the need for respiratory protection in the wui and what that protection would be. In a moment I'll return, I'll turn to Femi on this, who's directly done work related to first responders, but we did note these dramatic differences between the practices of firefighters in wildland fires versus urban structural fires and so the question came up what do you do at the wui so how do you address this. So I regained difference in health effects. I, I mean, what we found in the report is that most of the studies for firefighters has been in association with acute exposure acute health effects. Now for the general population. It's been more related with exacerbation of symptoms of chronic diseases. So there's some differences regarding available information with regards to respiratory protection. We didn't conclude on recommendation of any respiratory protection for wildland firefighters, because there's, there's not enough data to do that. Great, thank you. Our next question is, does the report assess whether wui fire smoke is more harmful than wildland fires. And did you find any evidence that one travels or stays in the atmosphere longer than the other. So two quite distinct questions and I'll turn to barb in a moment for the residence time in the atmosphere and how things might change as you change the emissions associated with wui fires it's a complicated question. And certainly, we know that there are significant differences between the emissions associated with wui fires, and the emissions associated wildland fires and two areas in which the report really emphasizes that difference are in halogen chemistry and halogen chemistry. And I'll just give as a first example, the halogen chemistry focusing specifically on chlorine. And so, but the report is more extensive than the answer that I'll give to you here so I urge you to read the chapters in the report dealing with the combustion chemistry as well as the atmosphere of transport and transformation. With structures, you can have substantial quantities of chlorine that are present in the fuels just think of the plastic polyvinyl chloride, which has substantial amounts of chlorine in it, which will be emitted in various chemical forms as as the plastic is combusted. And so you have very different species that can result. Again, as I pointed out, depending on what the combustion conditions are, but you could have chlorinated organic species of all sorts of types that get formed. Now, once you have those chlorinated species in in the emissions, they'll have an influence on the atmospheric chemistry as it goes downwind. And at this point, I'll turn it over to Barb to talk about some of that chemistry, and then also some of the other phenomenon that might change the pattern of how far these wui related emissions will be transported downwind. You saved the hardest part for me. I will say, I'll just back up a minute and say that one of the things I was surprised by when working in this committee was just how much plastic there is in, you know, urban areas and involved, you know, in houses and so on. You know, I think that in the atmospheric community, we know a lot more about what happens in wildfires as the emissions leave the fire zone and move downwind and cross the continent even. And we, and it's very, it could be very interesting to try to understand how the effects of more a lot more partially decomposed plastic materials and metals, and the, you know, nitrogen species how that affects the chemistry, and how that alters the chemistry that you would get from a wildland fire. But, you know, I don't think we know enough to conclude that the extent that the extent of the plume is any different. But we know that the composition, the compounds that form in the atmosphere through photochemistry and multi phase chemistry are probably different. Right. And we don't really understand. You know, how big that effect or small that effect is right so the differences could affect to what extent they, you know what their life atmospheric lifetime is and whether they deposit through what deposition or dry deposition where they end up. And whether they affect water systems downwind, for example. And I think this this question brings up a lot of things that are sort of pervasive throughout the report that over multiple decades we've learned a lot about structure fires we've learned a lot about wildland fires. And now, as we try and understand what's happening at the wui, we're making inferences so we can make inferences like well, we know there's lots of plastic there. That's going to lead to halogen potentially halogen radicals present in the flame as well as influencing downwind spirit chemistry. So we're making inferences we're developing hypotheses and there's very few data against which we currently contest those hypotheses. An example question would be, you know, are there compounds that are good markers of wui fires, or atmospheric formation products from wui fires. And can you measure those in the atmosphere then how far away can you measure them right. Okay. How far away can you tell that that was a wui fire and not a wildfire example. Great, thank you both. Our next question is related and I think you've touched on a little bit of it already but you mentioned the wind in general plays an important role in wui fires. So does wind result in more complete combustion and therefore less hazardous smoke and wui fires. Well, it will be important, and will influence not only the oxygen available, but also then just the heat transfer away from the fire. And so, I don't think that there's a simple and universal answer to the question about what the role of wind is because some of the case study fires that were looked at were fires that were driven by extremely high winds, and the combustion was quite intense. And these winds are localized and so they may or may not influence the transport of the result of the emissions and the resultant temperatures hundreds or thousands of kilometers downwind so so we expect that it's a complicated dependence on wind. So not a simple answer I'll invite any committee members want to add anything to that to chime in any additional thoughts on that Amara. I would say at a localized level, we would expect that there may be punching costs from strong winds as they would share across the combustion so there might be pockets of incomplete combustion where your flames are basically blown off of the fuel. I don't think it's so straightforward as it's going to cause complete combustion we're safe. It's also going to drive fire spread. So it's going to serve to drive these embers off the structure that's burning and spread the fire to the next structure over the next structure over. So it's definitely a complicated process there with the wind and we do expect it to be one of the biggest factors in the combustion environment. Thank you. And continuing the same line of questioning. Our next question is, you mentioned in the presentation that wooey and wildfires are different things but it seems some wooey fires may start as wildfires the campfire for instance if we've already discussed. Did you discuss on the panel how you draw the line between wooey and wildfires is a wildfire considered a wooey fired, only when it starts burning structures or just by getting close enough. There is not a universally accepted definition of what constitutes the wildland urban interface so as a working starting point and this is all described in chapter two of the report. We used a definition that came out of the federal register and that thereafter the Forest Service adopted related to the density of structures and the proximity of a large enough area of vegetation. Really, there isn't a universally accepted definition of what constitutes the wildland urban interface but we use that operational definition. As we begin to try and understand things like well what are the, what are the fuels that are that are present at the wooey getting a community research definition and an operational policy definition of what constitutes the wooey would be very valuable there, there are multiple definitions out there though. And the one that appeared in the federal register originating back from around the year 2000 is what we use because it had been used by the Forest Service to identify the extent of the wooey nationally and a number of subsequent analysis. Great thank you and then one additional clarifying question. When the report talks about the wooey. Is it mainly specific to homes when you talk about structure fires or it also includes local businesses. Yeah now start answering that question but I imagine other committee members will have things to add to this as well. Our charge question particularly looked at residences and you'll see I think the word residences in our statement of task, and also a great many residences are are present at the wildland urban interface nevertheless, we're cognizant of the fact that you're going to have businesses you're going to have a number of other types of structures and operations activities that occur at the wooey, and those can lead to different types of fuels. We used as examples in the report primarily residences, because it was identified in our statement of task. And then it's also residences are one of the dominant structural types, but things like vehicles, for example, particularly as vehicle types introduce new types of materials that might become fuels at the wooey. Anyone else want to add anything to that. I just add that we recognize that there were other potential structures or facilities that might be involved in fires a notable one would be like the Sarah Grande fire that was threatening radioactive storage facility I believe and then the car fire that was near a super fun site. We decided that it was out of our scope of statement of tasks and really address those in a comprehensive way but we did note that there are other areas and other facilities and structure types that may have very different concerns associated with them apart from the residences that we really focused on. We did look at some of our case study fires and some other fires that have happened in the past few years and identified that really residences make up about 80% or more of the structures that are involved in in a wooey fire. And so we're really capturing a large amount of the structures by just focusing on the residences in this report. Thank you very much. And were there any microbiological concerns identified with movie fires either public health or biogeochemistry. I'm going to turn to Fernando to see if he wants to address that in the context of public water systems. We, this falls this. I thought about it this falls beyond the scope of what we wanted to do which was related to the more chemical aspects. When it comes to microbiological aspects are obviously concerns with operations. Once you for example, maybe on the conditions that we share producing potable water that doesn't quite meet your target removal for to beauty for example, but overall this is not something that we consider in the report. Great. Thank you for clarifying. And did the committee look at the extensive published data on structure fires toxicity from missed, which was started in the early 70s because of the high number of deaths, which have now been greatly reduced using specific measures. We really looked at literature that existed on a variety of different types of structure fires obtained in a variety of settings. Amara, do you want to add, do you want to address that and what that section of the report described with respect to what we know about structure fires. We drew upon some of the methodological work that's been done to develop systems to identify smoke toxicity, and we relied along on much of that data to inform what we think might be emitted from a movie fire. We're talking about small scale tests like cone calorimeters to furnace methods that have been developed to go through the different phases that you might see in a structure fire. So we pulled on that data to look at how the different oxygen conditions might impact the emissions to give us some bounds of what we might anticipate the emissions would be from an urban fire. So we certainly scoured through the literature and we recognize that there's quite a lot of work that it's been done in this area on structure fires and toxicity that was helpful for informing this report. Another question is, why do you think the knowledge gaps that you point out in the report and in your presentation today are so numerous and what has kept more research or more findings from being concluded on movie fires today. So I'll like, I'll highlight two things that that the report emphasizes and then I'll go around and see if other committee members want to add their perspectives on why these knowledge gaps persist. And so one reason I think is the is the rapid growth of the wildland urban interface as a land category and the number of residences and and other structures that are present in the movie so this is a phenomenon that is growing and growing very rapidly so it's it's not an immediately new problem but it is a newer problem so that's one one feature I think in some ways though one of the bigger issues is that what you're really interested in is what's happening at the interface and getting measurements of what's going on at the interface is a really challenging problem and doing that in the field is when you're also trying to protect human life and property is a really challenging task. And so those are two reasons why I, I think there are lots of knowledge gaps to other committee members want to add things to that. Okay, I guess I would just say it takes agility, I think, to get that kind of data that that you need right because you don't know where the fire is going to be until the last minute. You kind of have to be ready to go. And that means it's really useful to have, you know, maybe some index variety of inexpensive sensors and some satellite data but also mobile van and airplane with real time instrumentation. It's something that has to be planned and coordinated in advance and, and then you've got to be ready to go where the fire is so I don't think it's easy, but we've learned a lot in the last few years about wildfire chemistry. And, you know, that was also had the same problem. So, I think it can be done. Although we, we did note it at various points in the report that with wildfires, you can take advantage of prescribed burns to go out and collect data where you can set up a logistics ahead of time, and be ready to deploy advanced instrumentation for a fire like that. And it's much less likely that something like that is going to happen where structures are also involved. I just like to add on on the ambient monitoring side is that we really have focused on our criteria pollutants of course they're important but not chemical speciation measurements we really don't have an extensive network of ambient monitoring that's just ongoing that could capture these and I emissions and identify them as such. So there, there are some gaps there, and as we start to have more speciated ambient monitoring networks, we may be better positioned to capture some of these emissions from movie fires. Great. Thank you all. And your mention of prescribed burns is a good transition to our next question which is, are there any recommended proactive mitigation strategies for reducing the risks of movie fires from your report. And I'm going to there. The main focus of the report in the statement task was on the chemistry associated with the fires and getting at the chemistry, but there were a number of points at which the report did touch on, on mitigation measures and some of those are to mitigate the risks. And I'll turn to Amara in a moment and see if she wants to comment on some of the mitigation measures that were that were described in the report, but then also one of the questions we touched on a bit earlier and I'll just see if any wants to add anything to this is mitigation of exposure by use of various types of protective equipment so let me first turn to Amara and see what she may want to summarize from what the report says about mitigation measures and reducing impacts of fires. So we reviewed the literature out there in this area to see what was being recommended of course there are multiple states and organizations that recommend different changes to building codes California is a notable one and that they've been very active and changing their requirements for building materials like moving to class A rated roofs, and having double paint windows, different types of changes that you could make to your structure to try and reduce its ability to ignite essentially. There's also recommendations on the land management side whether it be clearing of materials, of course this is like your defensible space type regulations to try and reduce the amount of flammables around the home. There's also recommendations for how to cluster communities and build them in a way that they have a buffer between them and wild lands, like a big water space, you know, like a lake or park area that would be well watered and would prevent us from the fire. And to summarize the available information out there that's been put forth as to mitigating fire spread into these areas and then limiting ignition in the building themselves it's certainly an active area of research, but there has been a lot of focus on trying to reduce the amount of fires in these areas. Let me any, anything you want to add to what you said earlier about mitigating exposures. So for community members. We, we touched on the use of a portable purifiers. We have clean clean clean rooms and clean spaces and using and 95 respirators for firefighters. I mean, for outdoor workers and 95 respirators possibility but for firefighters what might be quickly applicable is a skin hygiene. So, like I said before there is, we don't have enough data to, to touch on respiratory protection for wildland firefighters, but skin hygiene might be one way that exposure could be reduced and it's been shown in a couple of studies to have an effect. That's great thank you all for that information. It looks like we probably have time for two or three more questions. Has there been any research on using rapid deployment drones that have passive or active sensors to characterize movie chemical emissions. Certainly, in the chapter of the report dealing with measurements, we note those as potential platforms for going out and making measurements. I don't think we cite any studies where it's been particularly focused on movies, but certainly that was recognized in the report as an advance in measurement technologies that has applicability to movies. Great thank you. How much chapters findings or recommendations your report do you think are most important for emergency planners firefighters, others who are kind of the first to respond to fires when they happen. Yeah, so, and I'm not going to give you the chapter numbers because they kept changing and I'm prone to rattle off the wrong chapter number but there's a chapter on exposures and toxicants in the fires that was just before the measurements chapter. And that's really going to be the section that talks most about health effects, and particularly to first responders and communities, as well as as various mitigation measures associated So, I would direct readers to that chapter that the deals with exposures and toxicants. Great thank you. And can you talk a little bit more about the specific risks to certain groups of people or communities who may be particularly vulnerable to impacts of fires I think you mentioned in the report children, you know compromise people, etc. So there are multiple cases where there might be communities with additional exposures or enhanced exposures to wooly fires as well as the emissions from other types of fires, and I'm going to name a few but then I'll ask other committee members to talk about this as well and you can sort of go from the near field of the fire, the first responders and the communities nearby to further and further downwind. So one of the wrong categories of people who are going to be more exposed are people who need to work outside so if you're not in the needed fire region, but for example, the campfire in California resulted in significant levels of particulate matter in the North Sea and other emissions from the fire hundreds of kilometers downwind including all the people working outdoors in the Central Valley over long distances downwind. Similarly, individuals who don't have the ability to essentially close up their homes and prevent infiltration of the pollutants from fires far downwind. People who don't have the ability to move away from the impacts of the fires and have limited mobility. People who are linguistically isolated and may not get the messages that are broadcast about the risks associated with the fires. All these could be communities that have enhanced risk associated with wooly fires. So let me open it up more broadly to the community to the committee and see if they want to highlight other communities that are identified in the report. I just generally like to say the report talks about that people communities may be vulnerable because they're exposed to higher concentrations of pollutants, and they also may be vulnerable because of their underlying health risks that are exacerbated by the smoke, right. And so, you know those exposures sometimes come with their occupation, or with their, you know, ability to their social or family support so their ability to go move in with their another family member and get out of the way or their income their ability to throw some money at the right and go, go away and come back later. So there's both the health vulnerabilities and the exposures to consider in that question. And we talk about both of those I think mostly in that chapter. I don't want to say the number now because I will also get it wrong but on exposures and health effects. Thank you and it looks like we have just about a minute left but I'll just ask Dr Allen if there are any last closing notes he wants to make or messages he wants to highlight from the report before we wrap up. I want to thank all of you for your interest in the report and I'd also like to thank once again, the sponsors of the report, as well as all the committee members both for your participation today and then also for putting together this report so that we're all proud of the result. And I hope that you find the report useful. Great. Well, thank you all so much for joining us today. Again, I'll note that a recording of the session that's going to be available on the National Academies website in the weeks to come, so you can find it there. Once you exit this webinar you'll be redirected to our report page where you can download the report for free. So with that, I'll again thank our speakers and thank you all for participating today.