Wildfire health questions: Air quality, clean up risks and more

How trustworthy is AQI (Air Quality Index)? What is PM2.5? And at what distance does fire zone adjacency stop mattering? Is there a reliable way to test the safety of your water? Are kids safe indoors at school without masks?

KCRW and R&S Kayne Foundation Los Angeles held a public information panel and Q&A session on Jan. 15 regarding immediate and long-term health considerations for families and individuals returning to homes within the immediate vicinity of the fires and everyone coping with the recovery. This free virtual event provides evidence-based information and guidance regarding health concerns, including what you should or shouldn’t be worried about, exposure to environmental toxins from ash and clean-up efforts, and best practices to ensure children can safely return to their neighborhoods or, if needed, relocate. 

Moderator: Madeleine Brand, host of KCRW’s Press Play

Panelists:

  • Dr. Sarah Greene, Pediatrician
  • Professor Suzanne Paulson, UCLA urban environment wildfire specialist
  • Dr. Sande O. Okelo, Pediatric Pulmonologist
  • Professor Andrew Whelton, Purdue University environmental engineering

The event is available to view below in both English and Spanish. 

In English:

En Español:


About our panelists:

Dr. Sarah Greene received her bachelor’s degree from Northwestern University and completed medical school and pediatric residency at Vanderbilt University. Since moving to Southern California, Dr. Greene has cared for children in private practice, at Cedars-Sinai Medical Center, and as a faculty member at UCLA.

Professor Suzanne Paulson is the director for UCLA’s Center for Clean Air and a professor in their Department of Atmospheric and Oceanic Sciences. She received her PhD in Environmental Engineering Science at Caltech. She also holds two MS degrees, one in the same field at CalTech and another in Plant Biology from the University of Illinois. Professor Paulson is a decorated scientist and educator, currently holding a Fulbright Specialist Award and a National Science Foundation CAREER award. 

Dr. Sande O. Okelo is a practicing physician and Chief of UCLA Health’s Division of Pediatric Pulmonology. He’s an Associate Professor of Pediatrics at UCLA’s School of Medicine and also the Director for their Pediatric Asthma Center. Dr. Okelo received his medical degree from Case Western Reserve University and his PhD in Clinical Investigation at Johns Hopkins.

Professor Andrew Whelton is a professor of environmental engineering at Purdue University, and a water and environmental safety expert. He's been called in to help communities respond to and recover from the most destructive and deadliest wildfires in U.S. history. He's been asked for assistance by state executive leaders, the White House, and the Canadian government. Wildfire resources can be found at www.PlumbingSafety.org.


Questions and answers from the session have been adapted below from an automated transcript. Edited for clarity and length. Please consult the recording above to verify any direct quotes.

Q: We live within 10 miles of the Eaton fire and our two-year-old daughter goes to daycare two miles from the fire. Our pediatrician advised that she should limit time outside. We were wondering if our home and our daycare are considered unsafe now. And how long does she need to limit outdoor time? And should we consider relocating or sending her to a new school.

Dr. Greene: I really like that the person specified that level of detail because I think that has been the really hard thing with Los Angeles is that there's really different messaging that needs to get out depending on where you are in relation to these fires. I think this is a difficult question and I think it depends a lot on the air quality, which way the smoke is going, and which side of the fires you're on. So are you north? Are you east? Are you south? Are you west? I don't know if we know the answer to that question, but really following the smoke, the air quality – hyper-local air quality. 

And I like that she's distinguishing between daycare and where she lives because the air may be good where you are at home, but if you're traveling for activities for your kids, if you're traveling for daycare, my concern for that daycare is that if they're within two miles, did they get a lot of ash? What was their cleanup like? I would be asking the school, how did they clean up any outdoor space? Did they have to clean up indoor space? Did they have smoke damage if they were close enough to the fires? 

I think the house that's 10 miles away, it's probably more just immediate air quality concerns that I would be tracking right before you're going to do any activities. And it sounds, I think it was a two-year-old that she said, who's not going to be able to mask. If you have immediate smoke in your area, stay indoors.

Q: How long do you think she needs to keep her daughter inside?

Professor Paulson: Yeah, so there are a lot of the factors that Dr. Greene brought up are absolutely spot on. So the house that's 10 miles away, unless it was right in the line of the Eaton fire or possibly another fire and had a lot of ash falling, is probably not a significant concern. In, say, a week, all the smoke that was coming from the fire and maybe still hanging around in the near coastal region will be pretty much gone. So then it'll be back to normal urban air quality. 

It's always a good idea to keep an eye on the PM 2.5 concentrations. And I suppose if you're further inland on the ozone concentrations, consider that because we do have plenty of other conditions where we have pretty high air pollution. It wouldn't be a bad idea to try and reduce exposure by keeping a child inside. Just the act of coming inside, even if you aren't doing any filtration, will usually reduce the concentrations by about half. And then also when people are inside, they tend to breathe less, so that reduces their exposure.

So the daycare is, as Dr. Greene indicated, a very different situation. If that daycare was downwind during a lot of the fires, then it probably has been exposed to a fair amount of not just ash, but also the smoke particles will to some degree deposit. Some of the gases, the polyaromatic hydrocarbons, will slowly be off gassing. And to some degree getting resuspended so they can be cleaned up.

Q: What does PM 2.5 signify?

Professor Paulson: Very close to the wildfires, we have these very tiny particles called ultrafine particles. Those are not picked up by any of the sensors that we have out. But they're not super long-lived and they sort of grow into these larger particles that are detected and that are part of PM2.5. 

So PM 2.5 is all particles smaller than two and a half microns. That is the size class of particles that there's reams of data indicating results in all kinds of adverse health outcomes to young people, pregnant mothers, and older people in terms of cardiovascular events and respiratory events and all kinds of things. So they're highly problematic. Smoke produces both. 

It can also produce larger particles up to the size of ash that you can see floating around. Those generally don't get into the deep lungs, but they do get into the upper respiratory tract. They can be swallowed and cause irritation there. So large concentrations of those are also problematic.

So there are all these different sizes from all these different really tiny, like smaller than viruses all the way up to pieces of things that you can see. And those things are all lofted into the air and the very tiny ones are pretty resistant to removal by gravity. PM 2.5 particles stay in the air for about a week. Whereas the ash particles will fall out in generally tens of minutes unless they're lofted very, very high in the atmosphere.

Q: Should we be worried about those larger particles?

Professor Paulson: Those larger particles are really something that we're seeing some dust warnings. They're much more toxic than your normal dust. They contain a lot of heavy metals, a lot of polyaromatic hydrocarbons. One of the things that we get when we have structure fires is a lot of the wood is pressure treated. That contains a lot of chromium, copper, and arsenic. And all of those things, certainly including the copper, are quite problematic.

So that dust is not your garden variety dust. And so if you're near a burn area, you should be concerned about that dust. But further away, because most of that dust will have fallen out long before it gets these long distances. Although I do know that there was some ash that was deposited fairly far away. But generally further and farther away, you don't really need to worry about the dust any more than you normally would.

Q: How far away would you be okay from the fire smoke?

Professor Paulson: It really depends on the winds and the wind direction and how fires create their own weather systems and loft stuff quite high in the air. If there’s visible ash in your neighborhood then you should be concerned. If you can't see it then it's not such a big worry. If you're quite near a burn area like within a couple of miles, especially if you're downwind I'd be pretty concerned.

Q: Why are children more at risk of developing respiratory issues in wildfire smoke than adults?

Dr. Okelo: We know for children that they intake more air than adults. There's something we call minute ventilation, which quantifies how much someone is breathing. Children breathe much faster than adults, around two to three times faster. They're breathing in much more air, so their exposure level can be much higher than adults. That's probably the primary basis for why kids are more at risk. And never mind if they have any underlying health condition, but kids in general.

Q: What should parents of small children in LA be doing right now? Should they wear masks?

Dr. Okelo: I have patients all across Los Angeles County and even other counties. So it's tough to offer a single piece of advice, but I try to offer them some practical and actionable steps.

If the AQI is elevated, if you’re seeing ash, smelling smoke then take precautions. For patients that I have who are kind of particularly concerned, I do ask them to initiate kind of additional breathing treatments, for example as a precaution. Stay indoors if you’re able. If the indoor setting is not safe, then relocate. Seek evaluation if your child is experiencing symptoms whether or not they have an underlying health condition.

Q: Do AQI levels capture the full risk of airborne toxins to families?

Professor Paulson: The AQI is the best thing that we should be following. There are thousands of compounds in the air at very, very low concentrations. Decades of science have sort of focused on a handful of indicator species because if those things are elevated, lots of other things are elevated with them. And if they're low, then lots of other things are also low together with them.

Lead, airborne lead is actually one of the ones that is measured. So if the airborne lead concentrations got so high you know that would trigger an increased AQI. 

There are multiple particle ones, but National Ambient Air Quality Standards and whichever one is highest is the one that is determining the AQI in LA. That is almost always PM 2.5, sometimes in the summertime in the inland areas, it's ozone.

In the burn areas, there are other things that are important that are not measured by the AQI. In the burn areas I would recommend that everyone takes basically every precaution that they can. There are certainly polyaromatic hydrocarbons, potentially filter fine particles, some of these larger particles. There's lots of things. And all the particles contain heavy metals. The metals are not floating around freely. They're incorporated in the particles. Almost none of them have a gas phase. So there are definitely things that it would be great to measure that are not included in the AQI.

Further away from the burn areas, if the AQI is good then it means that the atmosphere is diluting the pollutants that we're producing and blowing them away, mixing them vertically, and they all get diluted together. If the AQI is good - that's great. I rode my bicycle to work today. I felt fine without a mask and I'm totally confident it was totally fine.

Q: Where’s the best way to monitor the air quality?

Professor Paulson: The Southwest Air Quality Management District maintains hourly maps of the air quality index. 

Purple Air Network is a little bit less controlled than ones that are run by scientists. So sometimes you see a really high value that might be somebody having a barbecue.

Another sensor network is the Clarity Network. They also have a map. LAUSD runs a lot of those sensors, which provides a little bit better coverage on some lower socioeconomic neighborhoods.

Currently under the fire conditions, there's an AirNow website, which is the EPA website. There's fire.airnow.gov.

Ignore the single values on AccuWeather or other weather sites, because they're often looking at 24 hour time scales. They're looking at much larger areas. They're just really not as useful as these dense networks that we now have.

Q: How long should people who live in the burn areas need to be worried about environmental toxins that were released?

Professor Whelton: So this debris has burned up EV vehicles. They have all sorts of heavy metals or acids and other gases, PAHs, which are larger compounds that can be toxic.

You really need to have some safety equipment before you go back to these debris areas. Even if that's just to look for items. You need respirators, long sleeves, long pants, and boots. 

Sometimes in some places we see underground fires still burning for weeks later. Pay very close attention to what's under your feet. And you definitely don't want to bring children or people with immunocompromised conditions to these areas.

As far as a time scale, listen to local officials. 

Q: What cleanup is necessary for outdoor recreational spaces like public parks, playgrounds, and pools?

Professor Whelton: Municipal employees, municipal organizations, and school superintendents need to engage experts. We need to deal with this carefully with people who can walk on site and say, you are definitely in a range downstream of the fire plume. This is definitely ash. We're not talking about COVID cleaning companies where they're coming in and they're using bleach on doorknobs.

Q:  How do you recommend parents help kids handle the anxiety that they’re feeling?

Dr. Greene: The Child Mind Institute has a great age-specific resource because this is going to vary if this is a two-year-old asking or an 18 year old asking. What applies to everyone is, be honest. Pause, ask follow-up questions if you're not sure what they're asking. They probably don't want as much information as you're wanting. Leave a lot of room for play and fun, recognizing that kids may kind of move along quickly and that's okay, too. 

Q: My house wasn’t burned but my neighbors’ were. What steps should I take to restore safety?

Professor Whelton: It's important to say that there's hope. You can restore your home to a safe environment. The way to do that is first to protect yourself, family, and friends from any hazards that might be there, like the debris.

If you have a standing home and it smells inside, you're going to have to have it professionally cleaned. And professionally means a company that comes in and remediates fire damage.

There might be a warning  that the water might be contaminated. For individuals that might have a home near another burn property definitely listen to the utilities to find out what the testing data say. Is this area contaminated or not? Then ask how long is it going to be for my utility to fix it?

Q: How long does water cleanup take?

Professor Whelton: In Pasadena, the water use advisory already shrank by about 30%. For other places where many, many homes burned down, it's probably going to take a little while for them to repressurize it, put water back in those pipes.

Q: Should I privately test my water?

Professor Whelton: At the present time, if they're under a do not drink or do not use advisory where chemical contamination is present: No. Chlorine test kits, VOC test kits are not even capable of finding the fire-related chemicals.

So you can spend 600 bucks on a test. After the Maui fires people sent me these tests, some people spent thousands of dollars and none of the information was usable. And so I would say hold off on testing until your water utility says that the water is safe coming into your home. Then you can figure out, okay, is my plumbing irreparably contaminated or not?

Q: Should I have the air conditioning on when I’m in the car?

Professor Paulson: Think of cars as indoor spaces, and if you have your recirculation on then you're not bringing in a lot of outdoor air. It's a good idea if you know you're going to go through a contaminated area to just  turn your air on recirculation.

You can't do that forever though because after 30 minutes or so the carbon dioxide concentrations actually build up inside the car and can make you sleepy. Also some cars have HEPA filters.

Q: What about in your house?

Professor Paulson: In most of LA, harmful particles are addressed really well with HEPA filters. If you're close to the burn area or in the smoke plume, then there are also gases that are not very effectively addressed by the HEPA filter. So you want to get rid of the particles with the HEPA filters, but then there are still also gases.

You can reduce your exposure to those just by being inside with the windows closed. That reduces many gases and particles by around 50%. If you have good HEPA filtration, you can knock the particles down by 95% or even more. The next step above that is a charcoal filter.

Q: Can children develop asthma that way and would they have long-term health problems from breathing in this smoky air?

Dr. Okelo: I think in terms of situations of damage, we're really talking about very proximal. Basically you'd have to be in a house fire or experience highly acute levels of exposure. That’s when we're talking about the risk of lasting damage to the lungs. I haven't encountered that situation a lot. It's been pretty unusual in my personal experience.

Q: If you do live in an area with tap water restrictions, can you shower, brush your teeth, or cook with this water?

Professor Whelton: You want to make sure that you read the drinking water providers warnings. Make sure that you know exactly what they're saying. And if they're not answering one of your questions, reach out.

Q: How do you handle smoke damaged furniture?

Professor Whelton: That's a personal decision that people are going to have to make, but you definitely don't want to use it if it smells like smoke. 

Q: What should pregnant people do in the upcoming days and months to mitigate risk?

Dr. Greene: So pregnant people are certainly at high risk for wildfire exposure. There are real risks to preterm birth after wildfires. Take extra precautions, I just wouldn't be in a fire adjacent area if you can avoid it.

Most of LA is safer now, but finding an area with good air quality if you do have to go outside is best. If you’re in an area with poor air quality or if you do for any reason have to go back to a burned area, wear a tight-fitting N95. 

Q: A few minutes ago, the city of Pasadena issued a public health emergency due to ash and particulates. But the AQI currently looks good. Will the AQI update to reflect this?

Professor Paulson: Probably not. The AQI is based primarily on PM2.5 and the other national ambient air quality standards. There is none for ash. That's indicating a burn adjacent area. Wear a mask.

Q: I live two blocks away from Eaton Canyon and found ash inside my home along with smoke smell. Our landlord does not want to make a claim with insurance. What can I do to make sure my house is safe for us?

Professor Whelton: We see this a lot after wildfires. So people that rent are generally in a more vulnerable position after a disaster like this. And it's important that they seek advice. So after approaching the landlord and asking and showing and taking pictures and documenting – I mean, through this entire process, you're going to want to document. You're going to want to document, document, and document because at some point somebody's going to say, show me what you were talking about. And you can't really explain it to them. You have to show them. And there's ways to free legal counsel that you can get in the community. You can talk to other people who've had similar experiences.

And also you can talk to your elected leaders. That's what we saw in Oregon where there was a mobile home park that was completely destroyed except a couple homes. And the home park owner didn't want to spend any money to do proper testing. Basically the state wasn't aware that this was happening. And so those individuals went to their elected leaders then started leaning on those businesses to treat them appropriately. And so this is, again, where you just have to navigate the system

I know you never wanted to do this in your life before. You never wanted to learn about this stuff. But in order for you to get your questions answered and addressed, this is the path forward.

Q: Will reverse osmosis water filtration systems with carbon filters filter out the harmful particulates?

Professor Whelton: So for drinking water contamination, the issues are dissolved volatile organic chemicals. Many people and even companies, we've seen this after fire. So a company, a home water treatment company will show up and sell $10,000 to give you this filter. You install it in your house. You never have to think about this again. But these devices are not certified to remove extreme levels of contamination. They can work for lower levels of contamination. But just installing them and not knowing what level of contamination it is runs a risk. Then you use the water. You don't test it because it's $125 per test. You give it to your family or friends and you can get sick. And so generally, I don't recommend installing any treatment devices until the utility is put on the table how much contamination there is, if any in your system. Then you can make decisions to figure out if spending thousands of dollars or hundreds of dollars is the right thing to do.

Q: How do you clarify and define fire adjacent area? Two miles, five miles, 10 miles?

Professor Paulson: I think that it really depends on where the wind was blowing and what was going on. But I think that if there's a reasonable amount of ash, there was smoke blowing in your direction at high concentrations for an extended period. Then you would be fire adjacent. But I know that there was ash falling out as much as, I don't know, 10, 15 miles away. I wouldn't really consider that to be fire adjacent. There was a little bit of ash that got lofted pretty high and then fell out there. There weren't necessarily a lot smoke impacts.

Dr. Greene: Would it be fair to say, like if you're standing somewhere, you can see the burn, assume you're fire adjacent? If you can see burned structures or if you go home and you have, like this person described, ash in your home, significant ash around your house, or smoke damage, certainly I would consider that place fire adjacent. But yeah, I think it's hard because I think of some of these fire areas, if the wind changes like that, that's also going to change which places are considered close.

Q: What are you most concerned about going forward for children and their lung health? What do you think parents should be on the lookout for?

Dr. Okelo: I think it boils down to two things, which our conversation has actually touched on this evening. I think one is the wildfire smoke risk. I think any of us who've grown up in California have seen a dramatic change in the frequency and intensity of these wildfires. And I think we just have to assume that that is going to be what the future holds for the time being. So I think it's factoring in all the information people have discussed today and being proactive about kind of planning for that. You know, we thought COVID was a masking era but you know I think now we need to plan for masking for future wildfires.

The second is also what people have touched on, and that's just chronic kind of particulate matter exposure. This information has been coming out for quite some time about the risk for people with underlying pulmonary and cardiovascular disease. So there is an opportunity for people to kind of factor that monitoring into their kind of daily planning for their children and otherwise. There's one project I've worked on where we've tried to assist asthma patients in quantifying that risk factoring in a variety of different information so that they can understand, you know, on a daily or weekly basis what their risk for having an attack is.

Dr. Greene: I agree with both of those from certainly from a respiratory standpoint. And I think like Dr. Okelo said, now is a really good time as we're thinking about this to get plans in place, have these masks available, get the good air filtration, and check your home HVAC. We didn't talk about that specifically, but you should check your home HVAC systems and what filtration you're using. Dr. Paulson, maybe you can speak to this better, but understanding a MERV 13 or higher, especially if there's concern about wildfire smoke and if you have a landlord, you can ask them the same question. Really push or even dig around and find the HVAC intake and check for yourself to see what filtration is there and ask for it to be improved if it's not.

But yeah, these are things that we should all be thinking about, our indoor air quality. I got a new filter and turned it on. It checks our air quality. And sure enough, when we started cooking dinner, that red light turned on. It's a good reminder that there's other things that are happening in our daily lives and in our lives that we should be aware of. So now is a good time to put these things in place. 

For our kids, you know, you touched on the mental health piece of this and that's always a concern after a disaster for kids and adults both. And that's something I worry about. I think one thing I just want to emphasize is that there is actually good data on that too. And there are things that people can do to build resilience. So things like this can actually lead to resilience also. We talk a lot about the mental health tolls that disasters take, but there's also ways that they can be a time for building resilience.

One of the main things that studies have shown is people who lean into community - either helping community or leaning in for support to their community - those people tend to come out of these more resilient people. So just encouraging people, I mean, just people logging on right now sharing this is community. But also just continuing to find support from people around you. Your community may look different right now than it did before but there are those people that you can reach out to. And we've seen that all over LA, that's been the silver lining.

Q: Panelists, do you have any words you want to say about what you're thinking about in terms of the future and what we should be thinking about?

Professor Whelton: Sure, I would just like to kind of reiterate what Dr. Greene mentioned. As you move through your community or be let back in, recognize that many of these utility workers, the water workers that are fixing the hydrant, or the fire chief - they lost their homes too. Some of them lost more than that. And so I think we need to make sure that we have compassion for these individuals. 

To give you some perspective: in Paradise, California, when I went in, we arrived to kind of help the community. We found out that more than half of the water utility workers lost their homes. And they were homeless. And then they had to move their families across the country. And then they came back to Paradise to help the community rebuild. And so I think that's really important to pay attention to because of the stress and maybe we're looking for an outlet to find a way back. Communities come back stronger. The ones that work together, the ones that communicate with their elected leaders.

I know I'm a professor and a scientist and engineer, but the big picture and what I've seen from these disasters is compassion, caring for one another. Trying to help one another drives communities back stronger and faster.

Professor Paulson: What you guys said is just really great. Yeah, I guess I would just reiterate to you if you're further away from the fire to just really not be super panicked about this. Life is pretty much going back to what it was. Maybe this is a call to pay a little bit more attention to air quality so that we can keep improving it and you can reduce your exposure for you and your family. But you can relax a little bit.