Fate of the inhaled smoke particles from fire scenes in the nasal airway of a realistic firefighter: A simulation study

Abstract

Understanding the inhalation, transport and deposition of smoke particles during fire missions are important to evaluating the health risks for firefighters. In this study, measurements from Underwriters Laboratories' large-scale fire experiments on smoke particle size distribution and concentration in three residential fire scenes were incorporated into models to investigate the fate of inhaled toxic ultrafine particulates in a realistic firefighter nasal cavity model. Deposition equations were developed, and the actual particle dosimetry (in mass, number and surface area) was evaluated. A strong monotonic growth of nasal airway dosages of simulated smoke particles was identified for airflow rates and fire duration across all simulated residential fire scene conditions. Even though the “number” dosage of arsenic in the limited ventilation living room fire was similar to the “number” dosage of chromium in the living room, particle mass and surface area dosages simulated in the limited living room were 90–200 fold higher than that in the ventilated living room. These were also confirmed when comparing the dosimetry in the living room and the kitchen. This phenomenon implied that particles with larger size were the dominant factors in mass and surface area dosages. Firefighters should not remove the self-contained breathing apparatus (SCBA) during fire suppression and overhaul operations, especially in smoldering fires with limited ventilation.

Keywords:

• CFD
• firefighter realistic nasal model
• firefighter respiratory health
• nasal deposition
• smoke particle dosimetry

Acknowledgments

Real time smoke particle size distribution and concentration in three fire scenes were obtained from Underwriters Laboratories’ large-scale fire experimental measurements.

Additional information

Funding

This study was supported by the National Natural Science Foundation of China (Grant No. 51706123 and 91643102), the National Key R&D Program of China (Grant No. 2016YFC0802801 and 2016YFC0802807), the China National Funds for Distinguished Young Scientists (Grant No 71725006), the Australian Research Council (Project ID: DP160101953 and DE180101138), and the China Scholarship Council (Student No. 201706210128). The authors are deeply grateful for this support.