Abstract No:
1696
Abstract Type:
Student Poster
Authors:
J Sterner1, T Bonney2
Institutions:
1JMS Environmental Associates, Ltd., Westmont, IL, 2University of Illinois Chicago, Chicago, IL
Presenter:
Joseph Sterner
JMS Environmental Associates, Ltd.
Faculty Advisor:
Tessa Bonney, PhD, CIH
University of Illinois Chicago
Description:
A quasi-experimental field study with repeated measurements was conducted to evaluate ultrafine particle concentrations during active abatement activities, where crews are utilizing large scale mechanical grinding.
Situation/Problem:
Ultra-Fine Particulates (UFP), or airborne particles with an aerodynamic diameter smaller than 100 nm, are a widespread component of environmental and occupational air pollution. Inhalation of UFP can lead to these particulate depositing through the bronchioles of the lungs, potentially inducing or exacerbating asthma, COPD, and other diseases.
High efficacy particulate air filters (HEPA) filtration performs at 99.97% for the majority of particulate sizes. HEPA utilizes filters from a mixture of glass fibers of carefully graduated diameters that give the required particle retention efficiency without exceeding the maximum airflow resistance criteria at the design airflow rate.
Most Penetrating Particle Size (MPPS) pertains to particulates which are 100-250 nm in diameter which interact with HEPA. The efficiency of HEPA filtration dips to around 80% with particulates in this size range due to the particle size being too small for capture by impaction and too big for removal by Brownian motion.
Workers who operate within constructed negative pressurized containments in asbestos abatement projects rely heavily on HEPA filtered face masks and air scrubbers for protection against fiber and particulate inhalation. Containment settings which utilize large scale mechanical grinding producing large amounts of dust emission within the work environment, which may present a significant risk of UFP exposures to workers.
The aim of this field study is to characterize the generation of UFP concentrations in asbestos abatement settings utilizing mechanical floor grinding, particularly examining whether the generated particulates fall into a Most Penetrating Particulate Size (MPPS) range in which HEPA filtration can occasionally not be as effective.
Methods:
Three readings were taken over two days during asbestos abatement activities at an active commercial warehouse (~3000 ft2 containment area) and office site (~1500 ft2 containment area) in December 2025.
Large scale mechanical grinding was taking place in the warehouse section of the project on both measured days. The large-scale grinder utilized was an AC Tech Prep Master, operating at 240 volts. The attached large-scale HEPA ported filter was a Rumac Model No. DS2720CON W/DBOX.
A TSI P-Trak Ultrafine Particle Counter 8525 condensation particle counter (CPC) was utilized to take UFP concentrations in particles per cubic centimeter (pt/cc). The CPC has three separate data reading modes. For this study, concentrations were taken in sample mode, which captures a single, ten second average data point. Three areas in the active abatement site were used to take measurements: inside the containment before HEPA filtration, inside the air scrubber exhaust tubing after HEPA filtration, and outside air ambient concentrations.
Results / Conclusions:
The abatement site for 12/8/25 and 12/9/25 readings consisted of an active commercial warehouse and office area. The warehouse containment area consisted of approximately 3,000 square feet, and the office area containment 1,500 square feet. The volume of the warehouse was approximately 35,000 cubic feet, and the office area 15,000 cubic feet.
The crew consisted of three workers and one foreman. One worker operated the large-scale grinder, while other crew members performed other tasks around the area.
Between nine to ten readings were collected at each of the three collection points. Averages of the captured readings showed much lower concentrations inside the air scrubber exhaust tubing after HEPA filtration, compared to readings inside the containment before HEPA filtration, and outside aur ambient concentrations.
To note, that further analyses are in progress and final results are anticipated in April 2026.
Findings from this study will contribute to a better understanding of UFP exposure during mechanical grinding operations and may inform exposure control strategies in abatement environments.
Core Competencies:
Indoor Air Quality
Secondary Core Competencies:
Engineering Controls and Ventilation
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
Asbestos, lead, and dust
Indoor air quality
Based on the information that will be presented during your proposed session, please indicate the targeted audience practice level: (select one)
Practitioner: Practitioner is a job title given to persons in various occupational fields who are trained to assist professionals but are not themselves licensed or certified at a professional level by a certification body recognized by the National Accreditation Recognition (NAR) Committee of IOHA. The IH/OH practitioner performs tasks requiring significant knowledge and skill in the IH/OH field, such as conducting worker exposure monitoring and, in some cases, may even function independently of a professional IH/OH but may not be involved in the breadth of IH/OH practice nor have the level of responsibility of a professional IH/OH certified by examination.
The IH/OH practitioner requires a certain level of education that can be obtained from an accredited university or equivalent. Additional training in specific skill sets that provide additional career paths to the IH/OH practitioner can also be obtained. IH/OH practitioners may also serve as team leaders or project managers.
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 will help awareness to maintain effective particulate controls during active abatement sites in which large quantities of UFP are generated.
Have you presented this information before?
No
I have read and agree to these guidelines.
Yes