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

May 06, 2021

Information

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

April 19, 2021

ID6570

To CiteDCA Citation Guide

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.