Abstract No:
1660
Abstract Type:
Student Poster
Authors:
J Gallardo1, Y Ornelas Van Horne2
Institutions:
1University of California, Los Angeles, West Covina, CA, 2University of California, Los Angeles, Los Angeles, CA
Presenter:
Jazmine Gallardo
University of California, Los Angeles
Faculty Advisor:
Yoshira Ornelas Van Horne, MS, PhD
University of California, Los Angeles
Description:
Occupational and environmental exposures to methyl bromide (MeBr) pose significant human health risks, necessitating effective monitoring and communication of potential exposure to this fumigant for the worker and residential communities most impacted by its application.
Situation/Problem:
Methyl bromide (MeBr) is a chemical compound that has consistently been applied to protect crops and other commodities against pests around the globe for decades. MeBr was to be phased out in the United States by 2005 under the Montreal protocol due to its ozone-depleting properties, but critical use exemptions for agriculture, quarantine and preshipment have allowed for its continued use. Previous studies have identified MeBr as a reproductive and respiratory toxicant to humans. Past research has also documented fumigation applicators that have experienced neurological, psychiatric, and respiratory distress after exposure to MeBr. The EPA has also noted that if there is not proper adherence to safety protocols, fumigators may be exposed to the high levels of MeBr they work with. In Los Angeles County, the fumigation facilities that use MeBr are also responsible for exposing nearby communities to this toxic gas. The West Long Beach (WLB) worker and residential community is especially burdened by a combination of exposures from fumigation, freight, port, and highway pollution due to the nearby San Pedro Bay port complex. Our goal was to use publicly available air monitoring data to observe trends in MeBr concentrations in the ambient air near a fumigation facility in WLB, and identify whether or not state-level recommendations for increased engineering and administrative controls and the implementation of a state-owned monitor has impacted the emission of MeBr since 2023.
Methods:
Air monitoring hourly data files between January 2023 and February 2026 on MeBr concentration in WLB were downloaded directly from the California Air Resource Board and South Coast Air Quality Monitoring District data dashboards. Data cleaning, quality assurance, and analyses were conducted using R Studio (version 2025.09.2+418).
Results / Conclusions:
Preliminary findings showed that average hourly MeBr concentrations in WLB air in 2023, 2024, and 2025 were approximately 1.41 ppb, 2.40 ppb, and 0.946 ppb, respectively. The chronic reference exposure level (REL) established by the California Office of Environmental Health Hazard Assessment (OEHHA) of an average yearly 1.2 ppb of exposure to MeBr across the lifetime was exceeded in 2023 and 2024. The highest peaks in monthly MeBr emissions hourly averages by year were observed at 4.54 ppb in March 2023, 10.1 ppb in February 2024, and 3.55 ppb in April 2025. Seasonal exposures peaked in Spring of each year, with averages of 5.31 ppb in 2023, 4.56 ppb in 2024, and 2.75 ppb in 2025. Between January 2023 and May 2025, there were a total of 1131 hours with exposure above 1.2 ppb–equivalent to more than 47 days in the 2.5 year timespan. Overexposure to the toxicant is harmful for residential communities living near fumigation facilities as well as the workers applying MeBr to freight in the same localities.
Core Competencies:
Exposure Assessment
Secondary Core Competencies:
Community Exposure
Total Worker Health ®
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.
Exposure Assessment
Gas and vapor detection
Hazard communication
Regulatory Compliance
Risk assessment and management
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 work advances IH/OH work by demonstrating how publicly available environmental monitoring data can be used to assess real-world fumigant exposure trends, evaluate the effectiveness of regulatory controls, and identify worker and community populations at risk of chronic exposure.
Have you presented this information before?
No
I have read and agree to these guidelines.
Yes