Abstract No:
1670
Abstract Type:
Student Poster
Authors:
H Almony1, C Tsai1
Institutions:
1University of California, Los Angeles, Los Angeles, CA
Presenter:
Hana Almony
University of California, Los Angeles
Faculty Advisor:
Dr. Candace Tsai, ScD, MS
University of California, Los Angeles
Description:
The surge of urban wildfires across Los Angeles County in early January 2025 released hazardous air pollutants and ash, raising environmental concerns and potential health risks associated with toxic particulate inhalation among workers in post-wildfire settings. To test the cytotoxicity of nanoparticles in wildfire ash, we designed an in vitro model to examine the inflammatory responses and cell death of human bronchial epithelial cells.
Situation/Problem:
Our goals are to identify the hazardous particles and perform a toxicological analysis comparing wildfire ash collected from the Palisades and Eaton fire sites. Wildfire ash can contain hazardous contaminants, including various heavy metals, particularly when fires occur in residential areas. Inhalation of fine ash particles may induce cytotoxic responses in human bronchial epithelial cells and directly impact the respiratory system and carcinogenic risk.
Comprehensive toxicological evaluations are conducted using ash samples at three exposure concentrations and a duration period of 24 hours to assess cytotoxic effects. The proposed research utilizes non-tumorigenic human bronchial epithelial (BEAS-2B) cell lines for in vitro toxicology testing.
Methods:
Inductively Coupled Plasma Mass Spectrometry (ICP-MS): Approximately 50 mg of weighed ash and soil samples from Palisades and Eaton fire sites was sent out for ICP-MS. Samples were digested in concentrated HNO with H,02 supplement at 190 °C for 20 minutes in a microwave digestion system.
Ash Preparation: Size selected ash particles are prepared by a density gradient centrifugation method, reducing to nanoparticle range (100-500 nm) to represent nano ash toxicity. Solutions of 20% and 40% w/v polyethylene glycol in water are used to separate smaller ash particles. The smaller sized particles are collected from the top and dried for experimental use.
Cell Culture: The BEAS-2B cell culture line is maintained in bronchial epithelial cell growth basal medium and incubated at 37 °C in an atmosphere containing 5.0% CO2.
Exposure and Cytotoxicity Assessment: Ash samples are diluted in bronchial epithelial cell growth basal medium to final concentrations of 0.1%, 0.2%, and 0.3% (v/v). Cells are exposed to ash samples from both wildfire sites and compared to an unexposed control group. Cytotoxicity responses are evaluated by measuring the release of interleukin-8 (IL-8) after 24 hours, using a Human IL-8 ELISA Kit and cell death.
Results / Conclusions:
ICP-MS analysis found elevated lead concentrations in soil samples from the Eaton fire site compared to state (80 mg/kg) and federal (200 mg/kg) regulatory guidelines, ranging from 261.888-316.562 mg/kg. The metal concentrations in the soil and ash samples from the Palisades fire sites did not exceed regulatory guidelines, however we cannot dismiss lack of health implications.
These results are a part of an ongoing study as we consider new emerging metals without regulatory standards and test for a dose-dependent response of how metal concentrations and particle size may influence toxicity and induce cell response.
This study provides a comparative evaluation of the cytotoxic potential of urban wildfire ash collected from multiple locations of the January 2025 Los Angeles wildfire event. Characterizing the biological response of bronchial epithelial cells to wildfire ash exposure may improve understanding of the mechanisms driving respiratory health risks associated with post-fire particulate matter.
Core Competencies:
Chemical Hazards
Secondary Core Competencies:
Exposure Assessment
Toxicology / Human Disease
Choose at least one (1), and up to five, (5) keywords from the following list. These selections will optimize your presentation's search results for attendees.
Aerosol and airborne particulate monitoring
Exposure Assessment
Toxicology
Based on the information that will be presented during your proposed session, please indicate the targeted audience practice level: (select one)
Professional: Professional is a job title given to persons who have obtained a baccalaureate or graduate degree in IH/OH, public health, safety, environmental sciences, biology, chemistry, physics, or engineering or who have a degree in another area that meets the standards set forth in the next section, Knowledge and Skill Sets of IH/OH Practice Levels, and has had 4 or more years of practice. One significant way of demonstrating professional competence is to achieve certification by a 3rd party whose certification scheme is recognized by the International Occupational Hygiene Association (IOHA) such as the Board of Global EHS Credentialing (BGC).
Was this session organized by an AIHA Technical Committee, Special Interest Group, Working Group, Advisory Group or other AIHA project Team?
No
Are worker exposure data and/or results of worker exposure data analysis presented?
No
How will this help advance the science of IH/OH?
This data can help us better characterize and understand the toxicological profile of wildfire ash, which is a source of contamination for worker and community populations and can help to validate whether there is a need for more direct characterization studies of these populations.
Have you presented this information before?
No
I have read and agree to these guidelines.
Yes