Climate Change and Health Seminar: “Links between Wildfires, Air Pollution, and Health under a Changing Climate”

May 06, 2021

Dr. Michelle Bell, Mary E. Pinchot Professor of Environmental Health at the Yale University School of the Environment

April 19, 2021

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ID: 6570
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00:01<v ->Okay, welcome everyone to</v>
00:04the Yale Center of Climate Change and Health seminar series.
00:08I'm Dr Kai Chen, assistant professor
00:10at the Yale School of Public Health
00:12and also the Yale Center on Climate Change and Health.
00:15So this is my great pleasure today to introduce
00:18our today's speaker Professor Michelle Bell.
00:21Professor Bell is the Mary E Pinchot Health Professor
00:26of Environmental Health at the Yale School of Environment.
00:30She's a recipient of many awards,
00:34including the Rosenblith New Investigator Award
00:38from the Health Effect Institute,
00:40the NIH Outstanding New Environmental Scientists Award
00:44the ONES award.
00:46Last year she was selected
00:48to the National Academy of Medicine.
00:51And I think there's no better coating
00:54for introduce her work from the National Academy
00:58of Medicine for her global latest
01:02in environmental health addressing critical topics
01:05such as air pollution and climate change,
01:08and introducing large-scale models that have
01:12advanced environment research
01:14at both global and local levels.
01:17So without further ado, I would turn the mich to Michelle.
01:23<v ->Great, thank you for that kind introduction Kai.</v>
01:26I'm gonna share my screen
01:28and if someone could give me a thumbs up to let me know
01:32if it works in presentation mode.
01:37Went to the bottom of the presentation for some reason.
01:39Is it working?
01:40<v ->Yes, it works.</v>
01:41<v ->Okay, great, thank you.</v>
01:43So thank you so much for spending some of your day
01:45with me here to let me share my work.
01:47I'm very excited to share this research with you.
01:50And I want to thank Professor Chan
01:52and Professor Dubrow for this invitation.
01:55I also wanna let you know I'm suffering
01:56from major COVID vaccine side effects.
01:58So, just be kind with me today (laughing),
02:02but I'm very happy to be here.
02:03So I'm gonna talk about some work we've done on wildfires,
02:07air pollution and health with a special emphasis on climate
02:10given the the sponsor of this seminar.
02:13And this is an outline of the talk
02:14I've prepared for you today.
02:15I'm gonna give some general background on wildfires,
02:18air pollution and climate.
02:20I wanna share with you some research studies
02:22that we have conducted looking at how air pollutions,
02:25or smoke from wildfires can impact human health,
02:28and some of the work we've done
02:30in the context of climate change as well.
02:32I wanna briefly share
02:33with you some ongoing and planned research
02:36and then I'll have a few concluding thoughts.
02:37So let me start with some background.
02:40So this is a slide that I've had for many years.
02:43Some of my students may recognize this
02:44and I update it every year just to show the number
02:48of peer reviewed journal articles
02:50on climate change in health.
02:52And you can see this just incredible growth.
02:55This is updated through 2020,
02:57where we have this incredibly strong scientific interest
03:01in climate change in health.
03:02And I would argue a public interest
03:04and perhaps, political interest as well.
03:07If we look at the major laws and regulations worldwide
03:11for the environment, not all of them
03:13but most of them relate to human health.
03:15And human health has been missing
03:17from much of the climate change debate.
03:19And so I think that this is actually
03:22really critically important in that
03:25this Yale Center that Kai and Rob run is really critical
03:29to advancing that effort.
03:31This is a figure, it's a bit complicated.
03:33I'm gonna walk you through parts of it
03:35but this is from a recent review article that we published.
03:39I'm gonna talk more about this article in a minute
03:41but we talk about the links
03:42between climate change, wildfire smoke and health.
03:45And my point for this figure is just to show
03:48that there are so many different pathways
03:50through which climate change could impact wildfires.
03:52It's not just that there's an overall warming.
03:55And so are you able to see my cursor maybe?
03:59Well, if you look in the upper right-hand side
04:02under climate change, you'll see there's high temperatures
04:05possibly lightening making a role,
04:07changes in precipitation,
04:09changes in wind patterns and so on.
04:11And then you see greenhouse gas emissions is combustion
04:14of fossil fuels leading down to impacts on human health.
04:17So my key point here being that there are a lot
04:20of really complex pathways through which climate change
04:23could impact wildfires, could impact human health.
04:26And this is from an article that not one of my articles,
04:29another researcher's article showing an increased
04:32in forest fires in the Western United States.
04:34And I wanna draw your attention
04:36to that lower figure with the red dots.
04:39And that's showing from 1984 to 2017
04:42this enormous change in wildfires, this is area burn.
04:47So this is not the smoke.
04:48This is the fire.
04:50I also wanna point out these kind of cyclical up and down,
04:55how we have this variation that goes up
04:57but in this zigzag pattern.
04:59This makes it very easy for someone either innocently
05:01or intentionally to downgrade or downplay
05:06the role that climate change has on wildfires.
05:10If they just pick off two or three points from this
05:13and there it looks like it's going down or not increasing.
05:18And I thought it might be useful today to take a step back
05:22to what I was thinking when I first started looking
05:24at wildfires and human health several years ago.
05:27And so I just was interested in this topic
05:29and started reading some publications
05:32from the United States government.
05:34And I just wanna point out two of them.
05:36One is from the US Forest Service, which noted
05:39that forest fire smoke was hazardous to human health.
05:41Even though there really has not been very many studies
05:44at the time, but they felt the US FS felt that
05:47given the overwhelming strong evidence
05:50that particulate matter from other sources
05:51is harmful to human health, we really should think
05:54that wildfire smoke is harmful to human health as well.
05:57And then I saw lots and lots of economic damages
06:00associated from wildfires.
06:01And I'm just pulling out one example here.
06:04So this is from NOAA, a US government agency
06:08and they estimated almost $7 billion in property damage
06:11and $58 million in crop damage
06:14over that period of about a decade.
06:17What's really interesting to me
06:19was part of why I got studied in this research
06:21is none of the estimates I found at that time
06:24considered human health.
06:25It's like nobody coughed, right?
06:27So my argument is that the damages from wildfires
06:31are grossly underestimated because they're not incorporating
06:35this change in human health.
06:36And that we had compelling evidence
06:38that wildfire smoke harms human health,
06:40but there's really a lot of uncertainty.
06:44And just wanna give a little more background
06:46about particulate matter.
06:47So particularly matter is
06:48the primary air pollutant we're concerned about.
06:51I just wanna give some background.
06:52I think many people on this seminar will know
06:55a lot about particulate matter,
06:56but in case you're not familiar maybe you work in water
06:59or some other field, it's really just exactly
07:01what it sounds like.
07:02It's particles in the air that can be made up
07:04of different chemical composition,
07:06they can have different sizes and different shapes.
07:09And then really the size matters a lot.
07:13So this is a schematic from EPA
07:16showing the width of a human hair
07:18and then showing how small these particles can be.
07:21I wanna draw your attention
07:22to what's (indistinct) the pink particles.
07:24Of course, they're not pink
07:25but in this figure of the pink particles
07:27showing that the PM 2.5 particles
07:30from combustion are very, very small.
07:32They penetrate deeper into the respiratory system
07:35than do larger particles.
07:36And this is what we're having
07:37from combustion from wildfires.
07:42Okay, I wanna go back to this review article
07:44that we published recently in
07:45the "New England Journal of Medicine,"
07:47and throughout the talk, I'm gonna highlight
07:49some of the researchers and collaborators.
07:50And so this photo is Rongbin Xu,
07:52who was the lead author on this paper.
07:55And so this is an article that's a review article
07:59that gives some kind of synthesis of what do we know
08:02about wildfires, global climate change and human health.
08:05I have a slide on some of our references
08:07at the end of this, if you're interested.
08:08So if you wanna know more about this topic
08:10and wanna read one article or small number of articles
08:14this might be one you wanna check out.
08:16And I wanna highlight that we went through
08:18and looked at the characteristics
08:20and health risks of wildfires.
08:21Like what's the state of the science.
08:23So let me blow up part of our table.
08:25So for mortality, we concluded
08:27there was consistent evidence.
08:29Those of you who have taken my class know that I
08:32and other people in public health are very cautious
08:35about using words like cause or proven or things like that.
08:39So we use a lot of this couched language,
08:41consistent evidence but that should by no means
08:45be considered that we don't have very strong evidence.
08:48It's just scientists being really careful.
08:51So we have consistent evidence that there's an increase
08:53in mortality from wildfire smoke
08:55and a real critical question is,
08:58are the particles from wildfire more
09:01or less harmful than particles from other sources?
09:04This is a broader question where we could look at particles
09:06from vehicles versus particles from coal combustion
09:08versus all combustion versus agriculture
09:11and now versus wildfires.
09:13And the evidence on this it's not perfectly consistent.
09:16So we said that for mortality
09:17wildfire particles may have a stronger effect.
09:20Now why would different sources
09:22of particles have different impacts?
09:24Well, as I mentioned, the particles have different sizes
09:26but they also have different chemical compositions.
09:28So if you have a particle
09:30that's coming a lot from oil combustion
09:32it's gonna have a lot of niclin vanadium.
09:34If it's coming from coal combustion,
09:35it's gonna have a lot of ammonium sulfate and so on.
09:37So different particles have different chemical structures.
09:40And we know these chemical structures matter
09:42for human health impacts.
09:44Although none of the particles are good for you.
09:46So this is why this is a critical question.
09:49We concluded consistent evidence of respiratory impacts
09:53maybe a stronger effect on asthma related events.
09:57So the basic summary of this table
09:59and my wording would be that we have very strong evidence
10:02that there is something happening
10:04for wildfire smoke harming human health,
10:06but there are a lot of unanswered questions
10:08that we could continue to investigate as well.
10:11So for example, the long-term health effects
10:13I've highlighted here we said they were largely unknown.
10:17So let me move to the second part of this talk
10:20where I really wanna highlight some of the research studies
10:22that my team has done looking at wildfire smoke.
10:26I wanna highlight my two key collaborators
10:28for this project.
10:29They're both at Harvard University, Francesca Dominici
10:32who's a biostatistician and Loretta Mickley
10:34who is a wildfire modeler amongst other things,
10:37amongst other types of air quality modeling.
10:40So I know there's a lot in this slide
10:41but let me just through some key features.
10:43So the first upper left,
10:46we started with forest fire emissions.
10:48And by we, this is Loretta Mickley
10:50who's an expert in this, and we have information
10:52on forest fires, on anthropogenic emissions,
10:55meteorological data we're using the GEOS-Chem model.
10:57And then as you move to the right,
10:59I don't know if you can see my cursor
11:00but these two orange blocks in the upper right.
11:02We have daily estimates of PM 2.5
11:05from all sources and from wildfire and from non fires.
11:10And then we can estimate the PM 2.5
11:12from wildfires specifically,
11:15This is an enormous advancement over
11:17some of the previous studies that look at satellite imagery
11:19and so on to really look at,
11:22does there appear to be a wildfire here, yes, no.
11:25Here we're actually estimating
11:27the actual level of wildfire pollution.
11:30And we're able to distinguish between particles
11:32from wildfires and particles that aren't.
11:35In the second aim, we're linking these estimates
11:37to Medicare data for the United States
11:42or for urban areas in the United States,
11:44trying to see if these wildfire smoke is associated
11:47with increase in hospitalizations
11:49and I'll show you some results later.
11:51And then in the third aim, we wanna look
11:53at what wildfires might look like under a changing climate.
11:58So in my talks, I like to give you a little peek
12:01behind the curtain of what's happening in the research.
12:03So this is what I'm gonna do right now.
12:06Sometimes I just don't like when I do this,
12:08you're giving away our secrets, but let me tell you
12:10some things that happened for wildfire smoke.
12:12So when I first started working on wildfires,
12:15the wildfire modelers, including Loretta Mickley
12:17and others kept talking about the validation of their model.
12:21This is what they were talking about is area burned, right?
12:24The models did very, very well for area burned,
12:26but I wasn't interesting area burned.
12:28I'm interested in this.
12:30So this is something really important for climate change
12:33human health research more broadly.
12:34And while we need interdisciplinary research,
12:37it's not good enough to just say my model was validated,
12:40validated for what?
12:42Validated to accurately estimate area burned,
12:45doesn't mean you're getting accurate estimates of smoke
12:49thousands of kilometers away.
12:51Alright, Loretta Mickley who's my favorite wildfire modler,
12:55one of my favorites.
12:55She got this very, very quickly.
12:57And so she went and did some validation
12:59of the wildfire smoke and we found
13:01that the models work well for that too.
13:05Next, I wanna highlight some of the research we've done
13:08looking at wildfire PM 2.5.
13:10So these are small particles fine particles in health.
13:13In the photo there is a one of
13:15the lead researchers for this work.
13:16She's a former PhD student Coco Liu.
13:20And so in this research, we had several challenges
13:23and I wanna highlight two of the key challenges
13:25to give you again a little peek behind the curtain.
13:28The first one is we really were interested
13:30in estimating wildfire smoke, the PM 2.5 from wildfires
13:35not just PM 2.5 during a wildfire.
13:37And we use that with our wildfire modeling and GEOS-Chem.
13:42The second challenge is one that we didn't really
13:44anticipate is that the day-to-day structure
13:48of how wildfire smoke varies in concentration
13:52is very different from other pollutants.
13:54So you can think of ozone is kind of low,
13:56it's high in summer, and it comes back down
13:58or it has a diurnal pattern
14:00and particles kind of do like this.
14:02Wildfires it's radically different.
14:04It's nothing, nothing, nothing crazy, crazy high,
14:06nothing nothing, nothing.
14:08So the traditional air pollution by statistical models
14:12to look at air pollution didn't function as well.
14:16So what we did and actually Coco
14:19came up with this new concept called a smoke weight.
14:21It's really analogous to a heat wave.
14:23So it's a series of contiguous days that have a high level
14:28of PM 2.5 specifically from wildfires.
14:32And we use this to characterize wildfire pollution episodes
14:36and compare the risk of different health events
14:37during that episode to non wildfire episodes
14:41that were not right up against that wildfire episode.
14:44So we used a variety of different definitions
14:48to categorize the smoke wave.
14:49I'm gonna show you some results,
14:50but you could really think of it too similar to a heat wave
14:53where you might have a heat wave defined
14:55as two or more consecutive days with temperature
14:58over the 95th percentile, or you could have three
15:00or more consecutive days,
15:01or you could use the 96 percentile and so on.
15:06So here's some of our results
15:08were published a few years ago.
15:10For this particular result I'm showing you
15:12it's a smoke web definition of two or more days
15:14with wildfire specific PM 2.5 greater than 37.
15:17That should be microgram per cubic meter.
15:19That's a typo, I'll fix it later, my apologies.
15:23And so what we've found or Coco's paper is that there was
15:27over 7% increase in respiratory hospital admissions
15:31for people 65 and older in the United States.
15:33Let's just the Western United States
15:35during smoke waves compared to non-smoker wave events.
15:39I wanna highlight another point here
15:40about epidemiological public health research.
15:43Sometimes when I'm talking to decision makers
15:45and people in Congress and so on,
15:477% might seem like a big number to them
15:49or it might seem like a small number to them.
15:52And my students know that I caution us
15:54against using words like only 72.2% or trying
15:59to make the number sounded bigger, sound small.
16:01I prefer to let the numbers speak for themselves.
16:03I do wanna point out that this number,
16:06the 7.2% increase is on everybody exposed to the event.
16:11So a 7% increase that only affected 100 people
16:15might have one public health burden,
16:16but a 7% increase that affects huge swaths
16:20of population in the Western United States
16:23is in much much larger public health burden.
16:27And next I wanna share with you some results
16:29where we looked at different types of smoke waves
16:32looking at intensity and also timing.
16:37So let's just look at the left-hand side.
16:39So this is again, the percent increase
16:42of respiratory hospitalizations in this case,
16:45looking at smoke wave intensity.
16:46And what you find here is that with as you move
16:49to the right-hand side of that left panel,
16:51the effect estimates go up.
16:52What this means is is that when smoke waves are more intense
16:56by which I mean a wildfire with higher levels of pollution,
16:59the risk goes up and you see a very clear trend.
17:01And that makes a lot of sense.
17:04On the right-hand side,
17:05I'm looking at the days within the smoke wave.
17:08Again, this is really kind of analogous to a heat wave.
17:11So the first and second day is not where we see
17:13the largest health impact.
17:15It was really on a week,
17:18but really the third to seventh day of the week.
17:20And then the effect went down later.
17:21So there's really some interesting things that we need
17:24to start thinking about for when in a smoke wave
17:27to the highest health impacts for respiratory causes occur.
17:30You can imagine this would be really critically important
17:32if you were trying to do some type
17:34of public health intervention.
17:39Now, let's take these estimates of wildfire smoke
17:43and start thinking about them
17:44in the context of climate change.
17:45And here again, I wanna give you another
17:48little peek behind the curtain.
17:49So we generated this map at the County level
17:52showing changes in different smoke
17:54with characteristics under climate change.
17:56This is what I call a middle
17:58of the road climate change policy.
18:00So it's not everybody goes crazy
18:02lowering greenhouse gas emissions
18:04and it's not everybody goes crazy
18:06raising greenhouse gas emissions.
18:07It's a middle of the road scenario.
18:09And we're looking at the change in the number
18:12of smoke waves from 2046 2051 representing the future.
18:16And this is really only for the fire season,
18:18to 2004 to 2009 representing the current day.
18:22And everything I'm showing you today
18:24is using state-of-the-art models.
18:25There's no reduced four models here.
18:28And what I want to just know before he went to the details
18:31of this map is that we generated
18:34an online version of this map,
18:35where you can click on your County or County of interests
18:39and look at different features.
18:40Look at the demographics of that County,
18:42look at the anticipated future demographics of the County,
18:45look at different features of a smoke wave and so on.
18:47And we spend a lot of time developing this map.
18:50And then we just hired a Yale undergraduate
18:52who did it in like a weekend, super quick.
18:56And then I asked him,
18:58can I hire you to do some more work?
19:00And he was like, no, I'm going to work at Google.
19:02So we lost our great map builder.
19:05But I think that my point I'm trying to make here
19:08is that this type of interactive map
19:10or some way are really helping get the results
19:14to a digestible usable format for decision makers
19:18in the general public is really critically important.
19:21And in some cases, it's very difficult.
19:23And in some cases there might be some easier solutions
19:27than we had thought of.
19:28Like in my case, hiring a undergrad computer genius
19:31to do it so that we didn't do it.
19:34So we have this map and we're looking at the difference
19:36in the number of smoke waves.
19:37And in green that shows that those counties
19:39will have fewer smoke waves in the future than they do now.
19:43And then going up to red where they
19:44have many, many more smoke waves.
19:46And we're gonna look at some other maps as well.
19:49And I want you to look at whatever section
19:51is of interest to you, but perhaps draw your attention
19:54to Northern California.
19:55So we see there that there's really
19:58either goes down for the number of smoke waves
20:00or perhaps it goes up a little bit,
20:01we don't have a whole lot in Northern California.
20:04I'm just using this as an example.
20:05In Northern California
20:06where we go to this really high level,
20:09but maybe those smoke waves last longer.
20:11So this is looking at the difference
20:12in the length of smoke ways where the previous one
20:14looked at the number of smoke waves.
20:16And here we see a different picture
20:19where we see again in Northern California,
20:21the smoke waves are not lasting as long.
20:23They're gonna be shorter, but for many
20:25many parts of the Western United States, in Colorado,
20:28Washington, Montana, Idaho and central California,
20:31the smoke waves are anticipated to last longer.
20:35And then finally looking at the intensity.
20:37So this is how much pollution is
20:39being generated by all these wildfires.
20:43And here, if we'd been looking at Northern California,
20:45we see that there really is a dramatic increase
20:48with Northern California having much more pollution
20:51from wildfires than they did previously.
20:54So another reason I wanted to show these maps is to show
20:57that these different characteristics of smoke waves
21:00or air pollution from wildfires, what metric you use
21:04in environmental health research more broadly
21:06can really dictate what the impression is to policymakers.
21:12And again, the false impression could happen innocently
21:14or it can happen on purpose
21:16but you could imagine someone looking at this map
21:19and just saying, smoke waves are gonna last
21:21a shorter period of time in Northern California.
21:23So perhaps doesn't look like a big problem
21:25but really things are much more complex.
21:27And overall, our results found that under climate change
21:30we anticipate the wildfires to occur more often,
21:34we anticipate them to last longer
21:36and we anticipate them to burn hotter.
21:40I wanna raise the issue of environmental justice
21:43which I'm using in the framework that environmental justice
21:46is the concept and the reality
21:49that certain subpopulations suffer
21:51a disproportionate public health burden
21:53from environmental conditions.
21:55And I wanna talk about this
21:56in the context of wildfires under a changing climate.
22:00And again, Loretta Mickley was our wildcard modeler
22:02on this project you see there.
22:04And then the other photo is Lucio Woo
22:06who's a former master student.
22:07She's graduated master's student
22:09from the Yale School of the Environment.
22:10And this was part of her master's research project.
22:13She did an amazing job.
22:15And so Lucio was interested in estimating
22:18what wildfire smoke looked like in Alaska.
22:21And so just to show you what that looked like,
22:25there's a map showing that we see an increase
22:28in smoke from PM 2.5 from wildfires
22:31by the 2050s compared to the present day.
22:34But we also see a very distinct geographical pattern
22:37where some parts of Alaska see a very small increase
22:40and some parts see a larger increase.
22:43Well, Lucio was also interested in thinking about
22:47which populations we're going to experience this increase.
22:51And she presented her work at a conference and meeting
22:54that involved many native American tribes in Alaska.
22:57And they gave her guidance on how to define
23:00the native American tribes for her research.
23:02So we followed their guidance, their self definitions
23:07of how they wanted this work done.
23:10And one of the things that Lucio notice is
23:12that the Alaskan Athabaskan tribe was really concentrated
23:16in certain parts of Alaska.
23:18And you see there that six to 13%.
23:21And here what we're plotting here
23:23are different native American tribes.
23:25Each tribe is a different color showing you the change
23:29or the smoke PM 2.5 exposure going
23:33from May to September,
23:35and is a function of where the tribes are located
23:38and where we anticipate wildfire smoke.
23:41You can see that this one tribe is really
23:43suffering a disproportionate burden
23:45of this anticipated increase in wildfire smoke
23:48under a changing climate.
23:50So large areas of Alaska would be anticipated
23:53to experience a double or tripling
23:55of monthly smoke exposure.
23:57So this is air pollution from wildfires by the 2050s,
24:01but there are very strong implications
24:02for indigenous people where these effects
24:04will not be experienced uniformly
24:07even across indigenous people in Alaska.
24:12All right, next I wanna share
24:13with you some ongoing and planned research
24:16that we have for the future related
24:18to wildfires and human health and climate change.
24:21And I put this figure here just 'cause I think it's neat.
24:24So anyone guess where my project is gonna be?
24:27You all know it's Australia (chuckles).
24:31So let me just start with these two projects
24:33that we have one ongoing and one's about to get started.
24:36So on the left, there's a project led by Yuming Guo.
24:39His photo is the far left of that photo
24:41right at the bottom, his photo is kind of in the middle.
24:44And Yuming is leading a project with many researchers
24:47around the world, including me and many, many others,
24:50but we're looking at wildfires and air pollution
24:52in relation to a variety of human health end points.
24:55And this was sponsored by the Australian Research Council.
24:58So some of the advantages of this project
24:59is we're really trying to go global
25:02and look at wildfires in different parts of the world.
25:05And then the second project which is planned
25:07and we hope to start out into this summer
25:10is looking at bushfires
25:11which is the Australian term for wildfires,
25:13and air pollution and risk of birth outcomes in Australia.
25:16And then I've listed the names there
25:18of the different collaborators, including Josh Warren
25:22who's a biostatistician here at Yale,
25:24and then several collaborators from Australia
25:28from multiple three different universities in Australia.
25:31And Yuming is in the middle there
25:32because he's in both projects.
25:34And so for this project, as you all know,
25:37Australia experienced devastating wildfires in recent years.
25:42And for this project, what we're really interested
25:44in looking at is how mothers exposure to air pollution
25:47from wildfires during pregnancy
25:49impacts risks of adverse birth outcomes,
25:51looking at things like low birth weight, preterm birth
25:54and a variety of other adverse birth outcomes.
25:58And we will be able in this project,
26:00we plan I should say, we plan to also look at differences
26:03for the indigenous population as compared
26:06to the general population overall,
26:08and also to look at differences by socioeconomic position
26:12and other types of factors that could be effect modifiers
26:15and mean that some subpopulations might respond differently.
26:19So I wanna highlight here again, the earlier work I showed
26:22from Alaska with Lucio Woo was looking
26:24at environmental justice with relation to exposure.
26:27In this work, we're also looking at environmental justice
26:30in relation to response to a given health outcome.
26:33So they're really multiple pathways
26:34through which some populations could have
26:36a disproportionate burden.
26:39Given the sponsor of the seminar,
26:41I wanna talk a little bit more about some
26:44our ongoing work looking at air pollution
26:46health and climate change.
26:47This work is not wildfire specific
26:49although, we may look at wildfires in here as well
26:53but this is work that was funded
26:54by the Welcome Trust Institute that has Yuqjang Zang
26:57and Northeastern University.
26:59And then you'll see our collaborators
27:01from multiple universities in Brazil as well.
27:04And here we're really focusing on two major cities,
27:06San Paulo and Rio de Janeiro.
27:09And these slides are kind of wordy so I apologize.
27:12But I'm gonna walk through our ongoing work
27:15and our plans for that.
27:16So we're gonna use state of the science air quality
27:18and climate change modeling to look at what
27:21different types of air pollutants might look
27:22like in the future for these cities.
27:24And for those of you who work with air quality modeling,
27:26that's our proposed triple nested modeling domain.
27:30For those of you who don't work with that,
27:31what that means is we start
27:32off with a coarser spatial resolution domain
27:35and then use the results from that modeling brand
27:38as the inputs and boundary conditions
27:39of a smaller domain and so on.
27:41And this is a technique that's been used for a very
27:43long time to get higher spatial resolution of estimates.
27:47We couldn't computationally run the high spatial resolution
27:50for the whole country of Brazil, for example.
27:52So just to summarize, we really wanna understand
27:55air pollution and weather today and in the future.
27:57Whether the levels of air pollution and weather
28:00throughout these cities today will have
28:02very high spatial resolved estimates
28:05beyond what we could get from monitors.
28:07And we'll also know what they're anticipated to look
28:09like in the future for air pollution or climate.
28:13Next, we wanna link those exposures to human health.
28:16And we're looking at mortality.
28:19Brazil as many of know is suffered greatly
28:22under the pandemic, and so we have had some struggles
28:26getting the health data from the government.
28:28This is not a criticism of them because they're busy.
28:30So the public health departments in Brazil
28:33are very busy dealing with more pressing issues.
28:36So that has slowed us down,
28:37but we still are getting mortality data
28:39for one of our two cities
28:41and we'll hopefully get the other city soon.
28:43So we really wanna look at how mortality changes
28:46from air pollution, heat waves, and also single days
28:49of heat and cold under the current climate,
28:53and then we'll estimate what
28:54those concentration response functions
28:57or exposure response functions might imply under
28:59future conditions where we've estimated those exposure.
29:02So we're linking air pollution or weather and health today,
29:05and then we're using this estimates
29:07to look at this in the future.
29:10Just another point I wanna make
29:12is I'm kind of peppering this talk with some
29:14of my thoughts on climate change research in general.
29:17I believe that it is critically important
29:19to understand these systems in the present day,
29:22before we start estimating what they look
29:24like in the future.
29:25So for example, I would like to know how people respond
29:29to heat waves in the present day,
29:30before we start estimating how people
29:32will respond to heat waves in the future.
29:34This is not a universally shared position
29:36amongst all climate change researchers,
29:38climate change and health researchers.
29:40And then there's two more tasks of this work
29:43I wanna share with you that are really exciting.
29:45One is looking at sector specific simulations.
29:48So by this, I just mean that we're gonna be able
29:50to distinguish between the air pollution coming from traffic
29:54the air pollution coming from industry,
29:56the air pollution coming from other sources.
29:58And so we'll be able to discuss and evaluate which types
30:03of sources of air pollution are more or less harmful.
30:06And this relates to the comment I made earlier
30:09about wildfire particles could potentially
30:11be more or less harmful than other types of particles
30:14given the different source
30:15and the different chemical structure.
30:17So here just to summarize what sources are most harmful.
30:20And then finally, we wanna look at co-benefits.
30:23So we're gonna analyze what would be
30:26some potential greenhouse gas emission policies
30:29that could take place today, and what would be their impact
30:32on not greenhouse gas emissions
30:34but on air quality in the short-term.
30:37So if we had something that, for example
30:40change transportation patterns
30:41or increased public transportation
30:43that might be a policy for greenhouse gas emissions
30:46but it would also likely lower particulate matter
30:49ozone, carbon monoxide and other pollutants
30:52in the near term, unlike the one to 10 year timeframe.
30:55So this term is really most accurately called co-impacts
30:59but it's commonly called co-benefits
31:02because they tend to be positive benefits.
31:04And so we really wanna estimate what are the
31:06short-term improvements in air quality from climate change.
31:09So next, I've allowed a lot of time for questions.
31:12I hope many of you are coming
31:13up with some questions or comments,
31:15but I just wanna give a few more just concluding thoughts.
31:18I just have a few more slides.
31:21So these are just some summary of the points
31:23that I tried to make today
31:24that they're multiple complex pathways
31:26through which climate change and wildfires interact.
31:30There's changes in the type of fuel,
31:32so that's what the wildfire modelers call trees is fuel.
31:36So there's changes in the type of fuel that could happen
31:39due to climate precipitation,
31:41as well as our anthropogenic management of forest,
31:44there's changes in the overall warming,
31:45there's changes in drought.
31:46It's really quite complex.
31:49And so we really take these estimates of wildfires
31:52in the future as kind of an overall estimate.
31:56We wouldn't look at like, what we think is gonna happen
31:58on July 5th, 2051 or something like that.
32:02But the state of the science models from Loretta Mickley
32:05and others show that wildfires are increasing
32:07in frequency, duration, and intensity.
32:09You'll notice, I didn't say is anticipated to increase.
32:12So that was done deliberately.
32:14So it was believed that the wildfires are already
32:18due to climate change increasing in frequency,
32:20we're having more wildfires, they're overall lasting longer
32:23and they're overall burning hotter.
32:26I wanna re-emphasize the point that exposure patterns
32:29due to where people live and where these
32:34smokes with fire takes place,
32:35the some populations are particularly vulnerable.
32:38Populations can also be vulnerable in other ways.
32:40One is one group might have a higher health response
32:43to exposure from smoke than others.
32:45Another is people might have different capacity to mitigate
32:48or adapt to these conditions like
32:51who can afford to move,
32:52who can afford filtration systems and so on.
32:55So there's really a lot of complex
32:57interesting aspects of vulnerability for wildfire smoke.
33:03And even though, as I showed in that review article,
33:05there are uncertainties and a lot of research to be done,
33:07like looking at birth outcomes and so on,
33:10there is overwhelming evidence that wildfire smoke
33:12does have a substantial public health burden.
33:15And as we anticipate wildfires
33:16and wildfire smoke to be higher in the future,
33:19we anticipate that burden to go even higher.
33:23And we still have some remaining questions.
33:25So some of the remaining questions
33:26and these are by no means all of them,
33:28but some of them are looking at other health outcomes.
33:30Most of the work to date has been done for mortality
33:33or hospital admissions, but you can imagine there
33:34many other health outcomes as well,
33:37looking at vulnerabilities, which populations
33:39are most vulnerable from a variety of pathways
33:42such as ability to adapt,
33:44such as baseline health status and so on.
33:48There's a lot of work to be done on links
33:50to chemical composition is the particles from wildfires
33:53will have different chemical structures
33:55than particles from other sources, as different sources
33:58have different chemical structures and many more.
34:01And then I wanna re-highlight this point of of co-impacts,
34:05which is commonly called co-benefits
34:07with climate change policy.
34:09So air quality policies are typically designed to
34:13well some of them can be designed for visibility,
34:15but they're most air quality policies are designed
34:17to protect human health in the short term.
34:19And then we have climate change policies
34:21that are designed to lower greenhouse gas emissions,
34:24but really many of the pathways through
34:29which these different policies take place can be similar.
34:32As I mentioned one earlier like
34:33changes to public transportation,
34:35changes to vehicle miles per gallon,
34:37lots of things like that.
34:38So many of the policies to improve air quality
34:42would actually lower greenhouse gas emissions,
34:44and many policies to avoid or mitigate climate change
34:47would actually improve air quality in the short term.
34:49So I believe firmly that both air quality policies
34:53and climate change policies typically,
34:56have both short-term health consequences
34:58and long-term health consequences.
35:00This has been known for a very long time
35:02but still to this day, they tend to be studied separately
35:05and even bigger, they tend to be analyzed
35:09in policy domains separately.
35:11Not always, there's a growing trend to look at this
35:13but overall, these policies tend to be looked at separately.
35:17And the point I'm trying to make here is that
35:19if we're looking at climate change policies
35:21and we wanna think about, for example
35:23the cost benefits of a given climate change policy,
35:25if we are missing the links to improve air quality
35:29in the short term and those health benefits,
35:31then we do not have an accurate estimate of the implications
35:34of that policy and are not making an informed decision.
35:37This links back to my earlier slide about studies
35:39looking at the economic impacts of wildfires
35:42if we're not incorporating
35:43the public health burden from wildfires,
35:45then we're grossly underestimating that as well
35:48and perhaps not making the most effective decisions.
35:51There's some references.
35:53So if you asked me for a copy of the slides,
35:55I'll be glad to share them with
35:56and you can see some of our references.
35:58And then finally, I wanna thank the people
36:00who really do the work which are my team,
36:02and you see many of them there.
36:04And so thank all of you
36:05and I look forward to your questions and comments.
36:09<v ->Thank you, Michelle.</v>
36:10This is a wonderful presentation
36:12and I'm sure the audience all enjoyed like I did
36:16and I'm sure there will be a lot of questions.
36:19But just a reminder everyone, if you have questions,
36:22please type it in the chat box.
36:24We have roughly 20 minutes for the Q and A section.
36:28But before that, I will start with some questions
36:31that we have already collected from the students actually.
36:36So one of the question is kind of related to
36:39Michelle you mentioned that we should really
36:42try to understand better our present day
36:44before we try to protect the future.
36:47So one of the questions from students
36:49they notice that that a lot of mechanisms
36:53are behind the climate change and wildfire
36:57is not very well understood.
36:59So how can we consider these unknown conditions
37:03or mechanisms when people want to do
37:07the future projection of wildfires?
37:10So how to consider this type of uncertainty?
37:14<v ->Yeah, so this is something,</v>
37:15so I'm not a wildfire modeler.
37:18And I also believe that people who have some caveat
37:21in my question right away, and I also believe
37:23that people who do that work well, really focus on that.
37:28So I wish Loretta Mickley or Yuqjang Zang were here
37:31to answer that question.
37:32So we know that there's some aspects
37:35but notice I'll still answer it.
37:36There there's some aspects of the wildfire modeling
37:39that we know work really well,
37:40and there other aspects that don't work as well,
37:43the same thing for estimating PM 2.5 more generally.
37:46So we can get pretty good estimates of PM 2.5 total mass,
37:50but we don't do as well and we try to look
37:51at the different chemical components.
37:53So there's really a lot of work
37:56looking at validating the models
37:59and seeing where it does well and where it doesn't do well.
38:02And where does well and doesn't do well
38:03could be in a literal where,
38:05like it may do well in some topographies than others,
38:08it may do well under some conditions than others.
38:11And really my understanding from working
38:13with the wildfire modelers is that we really wanna think
38:16of these as kind of large-scale estimates.
38:19So one of the things that we're looking at
38:24for the project we hope to get started
38:28that we'll be looking at wildfires in Australia,
38:31it does improve the underlying emissions inventory.
38:33So Loretta and her team have gone through
38:36the different pathways and trying to identify
38:39which ones are contributing the most to our uncertainty,
38:43and which ones are perhaps
38:45not perfectly captured by the model,
38:47but still maybe not making
38:50this big an impact on our estimates.
38:52And they have found that the underlying
38:54emissions of wildfires, this incorporates things like
38:58the fuel, the type of fuel by which I mean trees
39:01and vegetation, that that's really critical.
39:02So one of the main contributions that we're gonna make,
39:05and I really should say that Loretta and her team
39:07are gonna make to Australia is
39:08to improve those underline emissions inventories.
39:11And then we will be making those publicly available
39:12for other people as well.
39:14I just wanna highlight that some people have asked
39:17for a copy of my slides and I put my email in the chat.
39:21So if you're interested in a copy of the slides,
39:23I'd be glad to send them to you
39:24please just shoot me an email, thanks.
39:27<v ->Thank you Michelle.</v>
39:28I think your talk illustrated the complexity
39:33of this multidisciplinary work.
39:36So another question from the students
39:39they're more interested in how the local communities
39:43can do about it in the short term kind of mitigation's way.
39:48So can you share some of your suggestions
39:51the local community when they're facing the danger
39:55from climate change health can they do about it?
39:58<v ->Yeah, I wanna share a slide actually.</v>
40:03Can you see my slide, did it work?
40:05<v ->Yeah, okay.</v>
40:06<v ->So this is a figure that I just didn't include</v>
40:09an individual level protective measures
40:11from our review article.
40:13And here you can see we've kind of started at the top
40:18with most effective which is to eliminate the exposure.
40:21And so this is all based on the individual.
40:23This is not based on a like a federal policy.
40:26There's many other things they could do as well.
40:28So the first one, the biggest impact is to relocate, right?
40:36That could be permanent or temporary,
40:38but like to temporary relocate when there's wildfires
40:40and then there's engineering controls
40:42that can reduce exposure by 20 to 90%,
40:44depending on the quality of builders,
40:46none of them are perfect.
40:47You cannot get away from this with filters.
40:50Filtering industry doesn't like me to say that,
40:51but it's true.
40:53And then what we call administrative controls.
41:01So I'm gonna take a little bit of water.
41:06This vaccine is no joke.
41:09But yay science, I'm happy for it.
41:10So the third level down to shown in the kind of page
41:13is administrative controls.
41:15So that's things like staying indoors,
41:17avoiding heavy activity outside and so on,
41:20and then personal protective equipment
41:21like wearing a face mask and so on.
41:24And so you can see if we were to unpack
41:27this a little bit further, some of these activities
41:30are easier than others like wearing a face mask,
41:33it's not that hard.
41:34Some of them are harder than others,
41:35like to literally leave your home.
41:37Some of them may be more feasible
41:39for some people than others, like the financial cost
41:41of relocating, financial cost of filters.
41:44And some of them have other implications
41:46like social and cultural implications.
41:49Like, what does it mean if children
41:51can't play outside for months?
41:55So all of these things are really,
42:00I don't wanna say bandaid solutions,
42:01but none of them are fully satisfactory.
42:03But there are a variety of things
42:05that we've come up with to kind of highlight
42:08some things that an individual can do.
42:10But really what we'd love to do for exposure
42:13is everyone who works environment exposure knows
42:15is to stop the exposure itself from happening,
42:18rather than trying to address
42:20the public health on the backend.
42:23<v ->Thanks, Michelle.</v>
42:24There's a question from the audience from Glenn Homan,
42:28are children more vulnerable to the effects of wildfires.
42:32<v ->So that's a really great question.</v>
42:35And so I'm gonna couch it in two parts.
42:37So the first answer is we really don't know
42:39because there hasn't been as much research.
42:42The second part of my question is I would suspect yes.
42:45So children tend to be more vulnerable than healthy adults
42:48to air pollution in general, to particles in general.
42:51And there's a variety of reasons.
42:53Their systems are still under development.
42:56They breathe in more air per body weight than do adults
42:59and they historically spend more time outside.
43:02Although that's actually changed in the last few generations
43:05but historically they spend more time outside.
43:06So there's a variety of reasons why children
43:08are more susceptible to air pollution
43:11writ large than are like other healthy adults.
43:14Now, much older populations are also susceptible as well.
43:18And so while we don't have the evidence
43:20the strong evidence for this for wildfire smoke,
43:23I think it's certainly very plausible
43:25and I would argue likely
43:27that some of those same mechanisms
43:28would take place for children in wildfire smoke as well.
43:33But this is certainly an area where
43:34we need some more studies to really pinpoint it.
43:38<v ->Thanks, Michelle.</v>
43:39So I know we talk a lot about short-term effects here
43:44and the students are also wondering
43:47like what can the policymakers do to better report
43:54or even do research on the long-term health consequences
43:59of the wildfire exposure?
44:01<v ->Yeah, so I didn't mean to talk over you.</v>
44:06<v ->No, no, no, the student's question is just,</v>
44:09do you have any suggestions?
44:11What would be the important pieces to focus on
44:14such public health (indistinct)
44:16and how can we collect those data?
44:19<v ->Yeah, so there's a lot there.</v>
44:21And in the review article,
44:24I think I may have mentioned this
44:25that we categorized the health impacts
44:27of long-term exposure to wildfires as being more uncertain.
44:30So again, I'm gonna kind of answer
44:33this in a few different parts.
44:34So the first is it's more uncertain for longterm effects,
44:38much much more is known about short-term effects.
44:42Again, it seems very plausible that both will play a role
44:45because they do for particles more broadly, right?
44:48Short-term exposure and so by this I mean my exposure today
44:52and over the past few days, maybe to a week,
44:55my exposure to air pollution or
44:56in that timeframe matters for my human health
44:58but my exposure over the past several years matters.
45:01And actually my exposure in neutral matters,
45:03like everything matters.
45:05We don't know as much about that for wildfires.
45:08Some reasons why it's important to study
45:10and difficult to study is that the concentration levels
45:14for wildfire smoke are very different from other pollutants.
45:18As I mentioned, it's like nothing
45:19nothing crazy high, nothing, nothing.
45:22So what does it mean if you're getting
45:24those stressors or those crazy high?
45:27That's my scientific term
45:28the crazy high wildfire pollution.
45:30If you're getting it several times a year
45:33or every year, year after year,
45:36as opposed to just the impact from getting it once.
45:39And that's very different from kind of like my exposure
45:41to traffic particles, which is just going up and down,
45:45changes day to day of the week and so on
45:48but really is not having these strong events.
45:50So it's really these kinds of like huge stressors
45:53that come and go away and come and go away.
45:55So to understand that we need things
45:57like knowing where people have been for several years.
46:00We need really good estimates of wildfire exposure
46:02over several years, and I predict
46:04that some of the future areas of research for this
46:07will deal with some of the things on that previous slide
46:10relating to the other good question
46:11about individual level protective measures.
46:13So, this group of people
46:17had a pec major filtration systems
46:19and trying to stay inside,
46:20and these people were not able to.
46:22There's a lot of things there that we really need
46:24to parse out to really try to get
46:26a handle of long-term exposure.
46:30<v ->Thanks, Michelle, there are many other questions</v>
46:34from the students regarding
46:35especially on the review paper.
46:40But I also encourage the audience
46:42if you have questions to the whole talk,
46:45so please feel free to type in your questions.
46:48Or if you like, you can unmute yourself
46:50and ask the questions.
46:52I would just ask them one more question from the students.
46:58Kind of related to the individual level
47:01what the local communities can do,
47:03one of the ways is prescribed burning
47:08to mitigate the wildfires.
47:10So several students are kind of interesting,
47:12as a policymaker, how can you determine whether,
47:15just let it burn or do something additional about it.
47:21And students are wondering if there are any studies
47:26to look at this prescribed burning
47:29can we see does it cost effectively prevented the wildfires?
47:36<v ->Yeah, so the prescribed burning question</v>
47:38is very interesting.
47:39There have not been as much study
47:43on the health impacts of prescribed burn,
47:44but air pollution is air pollution.
47:46So prescribed burn which is being done
47:48is a forest management strategy
47:53is also producing air pollution.
47:55And so it's very interesting talking to communities
47:57and decision-makers on their different, enforced managers
48:01on their different perspectives and the different angles
48:05at which they're coming at this issue.
48:08So for many people in the community
48:09like all fires are bad in their perception,
48:12whether it be prescribed burn to stop a larger fire leader
48:15or whether it be a wildfire
48:17because they're getting the smoke of it regardless.
48:20And from a forest management perspective,
48:22you often will have prescribed burns
48:24deliberately to try to avoid that things later on.
48:27And I'm not a forest manager, but like these are done
48:31based on scientific research that
48:33we need to do this to control our forest.
48:36And then from a climate change perspective, we have to think
48:41about what does this mean for prescribed burns
48:43and the changing in vegetation patterns.
48:44Are we gonna have more prescribed burns?
48:46Are we gonna have fewer prescribed burns,
48:47but like what should we do
48:49for prescribed burns is very delicate,
48:52especially in terms of the research for air pollution.
48:55And I think that's part of why most
48:56of the research has really focused on wildfires.
49:01I think Rob may have been trying to chime in
49:03and then I also see a question in the chat.
49:05Rob, were you trying to chime in?
49:07<v ->Yeah, the first great, great talk, Michelle.</v>
49:12Yeah, I know your research focuses
49:15on the wildfire smoke and air pollution,
49:18but there's another element that I wonder
49:21if it's something that you've considered
49:23which is the help that when there are wildfires,
49:28people are displaced sometimes short term,
49:32sometimes longer term, you know people lose their homes
49:36and their lives are disrupted
49:38and there are potential health effects of that
49:41that could be disruption in medical care.
49:44And from what I've gathered, those longer term effects,
49:48those types of effects have really been understudied.
49:51And I'm just wondering
49:52if you have any thoughts about that aspect.
49:56<v ->Yeah, this is a really great question</v>
49:58and I wanna kind of unpack several things.
50:00So there's a lot to learn about
50:05our response to environmental disasters.
50:07And what does that mean in respect to human health?
50:10And what does that mean for respect to physical health?
50:13What does that mean with respect to mental health?
50:15What does it mean in respect to disruption of healthcare?
50:19There's some really great work that was done
50:21by a former master student, Leo Goldsmith
50:23who looked at a variety of ways
50:25in which the LGBTQ community has disproportionate impacts
50:29from environmental hazards.
50:30But one of them is disaster response
50:32where LGBTQ+ individuals are turned away at shelters,
50:37don't have access to their medication and so on.
50:41And then there's the
50:42also the issue of who can afford to move.
50:43There's also some great work being done
50:45by my PhD student Kate Burroughs, looking at displacement
50:49and migration from landslides in Indonesia
50:52and looking at the mental health
50:55and wellbeing aspects there's as well.
50:57But there hasn't been as much for wildfires.
50:59And I think it's something that probably
51:01needs to be looked at and I'm expanding it out
51:04to disasters more broadly.
51:05So like hurricanes, wildfires just
51:09the environmental disasters that we anticipate
51:11to be growing under climate change to happen more
51:14often to happen in a more intense way,
51:16what does this mean for the economic
51:19and health costs of relocation?
51:21What does it mean for the economic disruption
51:23of that community if people have to get up and leave?
51:26I mean there's all sorts of things that communities
51:28have talked about with me and wildfires in terms of things
51:31like my housing price.
51:35And there's designs of homes where you can like
51:39try to make sure you don't have brush near the house
51:43so that if it's a wildfire
51:44it doesn't zoom up on your house and so on,
51:47these things, it was very clear to me that these things
51:50are taking a mental toll as well.
51:53So I think this is a very understudied issue
51:56and I think there are multiple facets to it
51:59where different populations are affected differently.
52:01And this is something we really should be looking into.
52:07Can I answer the question in the chat next?
52:09Kai, is that okay?
52:10<v ->Yeah, please go on.</v> <v ->Okay, great.</v>
52:12Do you want me to read it?
52:14<v ->No, no, no, please go ahead.</v>
52:17<v ->Okay, I'm gonna read it.</v>
52:19And this is from Evan Brockman.
52:21As the climate health researcher,
52:22what changes would you like to see
52:23in data collection in regards to air quality?
52:25We are discussing what to add to our EHR as clinicians
52:28who directly see patients
52:29who suffer after exposure, thank you.
52:31So with respect to data, I'm not sure if the person
52:37that's in the question is thinking of health data
52:40or air pollution data.
52:41It kind of seems that maybe health data
52:45but I'm gonna answer all those questions (laughing).
52:48So with respect to air quality,
52:50we really need more monitors in rural areas,
52:54not just to try to study those populations
52:57'cause they're different but also the air pollution
52:59could be different as well.
53:00We are really hindered.
53:01This is worldwide by having our monitors
53:03being predominantly located in urban areas.
53:06With respect to human health,
53:07I think that there's some types of data sources
53:09for human health that we can get a pretty good handle on,
53:12like hospital emissions, mortality and other things
53:16that it's much harder to get a handle on.
53:18And just to get back to Professor Dubrow's point,
53:22like mental health and wellbeing.
53:24And so I think that some of those
53:28perhaps under the surface types of health outcomes
53:32that could have an enormous public health burden
53:33are ones that we really probably should start looking at
53:36more in relation to air pollution.
53:38I hope I've answered your question.
53:39I'm not sure if I misunderstood it, thank you.
53:45<v ->Michelle, I think there's another, yeah.</v>
53:48<v ->Okay, I'm gonna ask this, is the dense network</v>
53:50of low cost air quality sensors
53:52good enough to serve as input to your models.
53:54Well, it depends on the model and on the monitor.
53:58So we're often modeling at a nation level.
54:02So we would need like a huge network.
54:06And the low cost air quality centers,
54:09so cost and quality are associated in air quality monitors.
54:12So a low cost monitor can measure very, very well
54:15depending on what it's measuring or it might not,
54:18that's not a negative comment on those monitors.
54:20Sometimes that's perfectly good for your purposes.
54:24So I guess my short answer would be,
54:26it really kind of depends.
54:31<v ->Michelle, I have a question, all right?</v>
54:33You mentioned that I think why you initiated this study
54:38to look at the wildfires because when you look
54:41at previous reports on almost no damage
54:44was taking into account with the health burden,
54:47I think it speaks true for all
54:49the other extreme weather and climate change.
54:53So would you like to share more source more broadly
54:59the economy burden on climate change
55:01and how as a researcher, what we should do about it?
55:05<v ->Yeah, so I think that is, I alluded to</v>
55:09I think that human health is missing
55:11from part of the climate change discussion.
55:13And by the discussion I mean, in political decisions
55:18and in the general press and the mass media
55:21and in community discussions.
55:23And so there's a very different response to learning
55:29that sea level rise might impact a country halfway
55:32around the world, as opposed to learning that asthma rates
55:36in your community are likely to go up.
55:38We can discuss the ethics of that, but that's a reality.
55:42And I showed that slide at the beginning
55:45of the climate change human health articles
55:46have really been skyrocketing, but I personally believe
55:50it hasn't really caught up
55:51with the kind of the general discussion.
55:55So still when people talk about climate change
55:57they're often not talking about human health or not as much.
56:02And if you look at the predominant reasons
56:04that people have moved on environmental issues,
56:06the number one reason people care about the environment
56:08in most surveys is human health,
56:12although other things matter.
56:13So I think that's why Yale center
56:15and other work on the human health impacts of climate
56:18are really important for people to really understand
56:20the full magnitude of what climate change means.
56:24We're not just talking about loss of species,
56:26were not just talking about loss of land,
56:28we're not just talking about ecosystem changes
56:30but we're talking about actual changes in human health,
56:33which will be a huge driver for many people.
56:39<v ->Thanks Michelle, for the very insightful comments.</v>
56:42And I think we do have the last comment
56:45from a Pin Wom, thanks for the informative talk.
56:48How was the threshold for smoke we've determined.
56:51As you mentioned the smoke pollution
56:53is like non-crazy high num pattern.
56:56How important was the definition of threshold in this study?
57:01<v ->Yeah, similar to how you might do with heat waves,</v>
57:05we used a variety of thresholds, so we varied it.
57:08And we saw results that you would anticipate.
57:11So as we made the requirement more stringent,
57:14meaning we're forcing those smoke waves to be more extreme
57:18we saw higher health impacts.
57:19And then if we lax the response
57:22and allow the smaller smoke waves
57:24like you still have walked our air pollution,
57:26but it's not as high,
57:27we still saw an effect and it was lower.
57:28So I guess the short answer is it matters in terms
57:33of your specific numerical health effect estimate.
57:38But it didn't matter in the sense
57:40that we found effects at different types of definitions.
57:45And this makes sense too
57:46because there's nothing like magical,
57:48like two days matters, but three days doesn't,
57:51two and a half to, you know what I mean?
57:52So these are all like approximations.
57:54They're just trying to capture the smoke wave period.
57:57<v ->Wonderful, thank you Michelle.</v>
57:59I think I can speak
58:00for the whole center and all the audience.
58:02Thank you for giving us a wonderful and informative talk.
58:07And thank you all the audiences attending today.
58:10I think at a peak, we have almost 90 audiences.
58:15<v ->Oh great, thank you so much</v>
58:16for the invitation to share my work.