Image: Wildfires burning near Los Angeles, California, United States, January 2025. Credited to Getty Images and GDMatt66.

Recently, AIHA’s chief science officer, Michele Twilley, DrPH, CIH, spoke with Enrique Medina, MS, CIH, CSP, FAIHA, about the health and safety issues related to the fires in the Greater Los Angeles area. This post, the second of two that present excerpts of Twilley’s conversation with Medina, covers challenges facing OEHS professionals responsible for workers and communities affected by the fires. A previous post addressed the hazards from the perspective of returning residents and those living downwind of the fire.

Medina is the editor of AIHA’s Technical Guide for Wildfire Impact Assessments for the OEHS Professional and the president and CEO of Alliance Consulting International in San Diego. The following transcript has been edited for length and clarity.

Michele Twilley (MT): What would you like to convey to OEHS professionals and members of AIHA about wildfires?

Enrique Medina (EM): The first thing is that we have the Technical Guide for Wildfire Impact Assessments for the OEHS Professional. It offers good guidance for industrial hygienists on how to approach this issue. We're finishing up the second edition, which updates and expands on the original Technical Guide. It describes the means and methods for conducting wildfire impact assessments, whether for forensic investigation to determine level of impact to a structure to inform restoration, for exposure assessment for health risk, or both.

If you look at the photographs of the wildfires, the Palisades and the Eaton fire and the Kenneth fires, you almost think that they become structure fire issues rather than wildfire issues. The wildland fire might have initiated it, but the devastation is from one structure to another. It’s been referred to as an “urban wildfire” by a CalTech scientist. This may be the way we start to think about these fires from now on.

The state of California’s CalRecycle program has good guidance on what to do with demolished structures. There are hazardous waste issues to consider for workers. There is the necessary PPE and respiratory protection and the need to look at structural issues to make sure that they're not going to get in harm's way before starting the demolition.

When IHs come back to the companies they work for, if the buildings have survived but have been affected by thermal damage or infiltration of particulates, they need to do some good cleaning and look at their HVAC systems. They may need professional restoration. To start, they need to do an assessment of the level of impact from wildfire smoke infiltration. They should also find out what their employees are breathing before they come back, if they are going to be working inside.

When I was working the Woolsey and Hill fires in Ventura County, the Camarillo area, and Woodland Hills, which is close to LA, people were sent to community centers for evacuation, but those community centers were downwind of the fire, so they were also affected by wildfire residue. Some of those community centers offer childcare services, and so when they return to normal operation, you need to make sure you do very good cleaning and do an assessment of particulates and possible organics. There are going to be so many structure fire components—plastics, electronics, synthetic fabrics and furniture, the hundreds of vehicles that burned with lead acid batteries. They need to do a really good industrial hygiene assessment of conditions there.

MT: Is there anything else that you feel someone living in close proximity to the wildfires should know?

EM: Initially, maybe after basic cleaning, if you're an industrial hygienist, you can use our normal exposure assessment tools and approaches to determine if there is a health hazard to the occupants, especially if they are members of susceptible populations. In the case of professional restoration, the Technical Guide recommends post-restoration verification, a type of clearance testing designed for wildfire impacts. The problem we'll have is that the occupational standards do not apply to residential buildings. Other standards for exposure to the general public deal with chronic levels. One source they may want to consult is the Office of Environmental Health Hazard Assessment, which is part of Cal-EPA. They publish acute and chronic exposure levels for even the most susceptible populations.

A wildfire impact assessment for exposure is basically like doing a retrospective exposure assessment. You have to make a defensible case. You have to develop your hypothesis, know what you're testing for and how you're testing for it, and make a sampling plan. You need to have data quality objectives and quality control. If you're taking samples that need to go to a laboratory, you need to have a chain of custody. You need all those things to support your conclusions. If there are people who are experiencing health symptoms, have them visit a physician who can diagnose what the conditions are. This will inform what further steps you need to take.

MT: It sounds like it's a team approach. It's the homeowner or occupant, and then it's bringing in the different specialists you need, whether it's medical, insurance, industrial hygiene, or restoration and cleaning. There are a lot of people involved. I can only imagine, with something on the scale of the fires that are burning in the LA area, that resources are stretched thin.

EM: Yes, definitely. The initial part of the fire was in a very affluent area, but it has extended to other areas, including mobile home parks where people of lesser means lived. There are populations and communities in Los Angeles that are under-resourced and do not have many of the tools that the city provides in other areas. It’s a health equity issue. And there are people who, because of their socioeconomic conditions, already have some chronic health conditions that they need to address. And those people are most at risk because they won't be able to go to a clean air center. They may not have a portable air purifier. They may not have a good health clinic or health insurance. Some of them may do outside work at home or be outdoor workers, so they're exposed to those sources of pollution a lot more.

MT: I started thinking about all the people who will be responding to the cleanup efforts, to restore the burned area to something where the owners could rebuild or the communities could be re-established. And of course, that's a great place for the OEHS professional to be involved. We have resources that help point to the types of hazards that they might encounter in a burned structure.

EM: I think there's a big role for industrial hygienists both in the demolition and cleanup of these areas, as well as in the indoor air quality aspect for surviving structures. They will need to work with other disciplines. Knowing what terms those other disciplines use is really helpful.

We have experience in California of a large-scale demolition effort because of the Camp Fire in 2018. Cal-EPA was using federal EPA remediation screening levels (RSLs) to determine if there was waste that needed to be managed as hazardous waste, where you have to have a health and safety officer on the site and an industrial hygienist to monitor the workers. The California Department of Toxic Substances Control (DTSC) regulates hazardous waste remediation and asbestos abatement. Together with CalRecycle, they have a process for hazardous waste from wildfire demolition that includes site assessment, removal, soil sampling, and final inspections. These are roles IHs are familiar with and can bring a lot of experience to.

The size of this is tremendous. Insurance professionals will be there. Some of them will be public adjusters who work with the residents, and structural engineers may need to be involved. There are going to be a lot of different disciplines, so keeping our focus on how we do wildfire impact assessments and exposure assessments, how we do retrospective assessments, and using those tools that we're familiar with and adapting them to the nature of wildfires and what they leave behind and the potential exposures from those residues could be helpful.

To donate to L.A. wildfire relief efforts, visit the website of the American Red Cross, select “Disaster Relief,” and then select “California Wildfires.”

Resources

AIHA: Technical Guide for Wildfire Impact Assessments for the OEHS Professional (2018).

AIHA: Wildfire Safety Resources.