Fighting Fire’s Hidden Toxins: Chromatographic and Sensor-Based Strategies Against PAHs

A joint study between York University (Toronto, Ontario, Canada) and the University of Tehran (Iran) examined recent advances in polycyclic aromatic hydrocarbons (PAH) decontamination strategies for firefighting as well as explored alternative sensing solutions. Their work included the evaluation of both conventional analytical methods, such as gas chromatography (GC), high-performance liquid chromatography (HPLC), and mass spectrometry (MS), as well as emerging portable PAH detection technologies. Through the highlighting of the limitations of existing systems and presenting novel sensing approaches, the team hoped to catalyze innovation in sensor development, with the goal of creating a robust, field-deployable tools which would enhance decontamination practices, significantly improving the health and safety of firefighters by reducing their long-term risks of cancer. A paper based on their research was published in Biosensors (1).

Accounting for over 86% of work-related fatalities within the profession, with firefighters facing a 9% greater incidence of cancer and a 14% higher risk of cancer-related mortality; a primary contributor to this elevated risk of cancer is the exposure to PAHs, which are toxic compounds that are generated during the combustion of organic materials such as wood, plastics, and various synthetic substances (2–4). Because of their carcinogenic and mutagenic properties, PAHs such as carcinogen benzo[a]pyrene (BaP), represent a significant health hazard, so much so that they are classified as Group 1 carcinogens by the International Agency for Research on Cancer (IARC) (5).It has been determined that PAHs may cause oxidative stress, DNA damage, genomic instability, and hormonal disruption (6); once absorbed into the body, they accumulate in tissues such as the liver and lungs, and lead to lipid peroxidation, DNA degradation, and progressive cellular damage (7).

The researchers concluded that the increases in urban and wildfires in recent years has resulted in a significant rise in environmental PAH levels and direct exposure risks for firefighters. The addressing of this issue is critical for firefighter health as well as for protection of the entire community, due to the potential for these compounds to spread through the air and water. The confirmation that that firefighters face serious risks from exposure to combustion-derived chemicals, particularly PAHs highlight the critical need for methods for detecting and removing harmful compounds from firefighter environments. While the researchers state that advances in the analysis of PAHs using chromatographic techniques such as GC, HPLC, and supercritical fluid chromatography (SFC), as well as electrochemical and surface-enhanced Raman spectroscopy (SERS)-based optical sensors, have been thoroughly reviewed, there is still a need for replacing traditional sample preparation methods with advanced extraction and purification techniques for enhancing PAH recovery from both liquid and solid samples. Although most GC methods rely on flame ionization detection (FID), the team pointed out that studies using the more sensitive tandem mass spectrometry (MS/MS) detectors remain limited. Precise optimization of the column type and length, stationary phase, and film thickness, as well as temperature programming, are important for improving the resolution and reducing the analysis time in GC workflows (1).

In addition, although HPLC methods frequently employ fluorescence detection, the broader adoption of advanced MS/MS detectors remains limited. The use of ultrahigh-pressure liquid chromatography (UPLC)–MS/MS also presents challenges, particularly with short columns and small particle sizes, which can compromise robustness. Emerging supercritical fluid chromatography (SFC) techniques show promise for water sample analysis; however, their application to solid and more complex liquid matrices is still uncommon. By contrast, electrochemical and optical sensing methods are increasingly favored due to their enhanced sensitivity enabled by nanomaterials, as well as advantages such as lower cost, shorter analysis time, and suitability for miniaturization and in situ deployment. Notably, electrochemical sensors can achieve very high sensitivity through the synergistic effects of nanomaterials on catalytic activity combined with surface modifications of working electrodes (1).

While optical methods based on SERS (employing nanomaterials) have achieved noteworthy Raman signal enhancements, leading to high sensitivity, their application has largely been limited to detecting a narrow range of PAHs. This shows the need for multi-analyte sensor development, the researchers noted. Similarly, many existing sensing techniques have been confined to liquid-phase analysis, limiting utility in broader monitoring applications. Other persistent challenges include electrode fouling, peak overlap due to interfering compounds, and over-voltage effects which suppress electron transfer in electrochemical sensors. For SERS-based sensors, signal degradation due to continuous laser irradiation and distortion caused by functionalized molecules must also be addressed (1).

References

1. Ghafar-Zadeh, M.; Biyouki, A. A.; Heidari, N. et al. Protecting Firefighters from Carcinogenic Exposure: Emerging Tools for PAH Detection and Decontamination. Biosensors (Basel). 2025, 15 (8), 547. DOI: 10.3390/bios15080547
2. Praveenkumar, T. R.; Sekar, M.; Pasupuleti, R. R. et al. Current Technologies for Plastic Waste Treatment for Energy Recovery, It’s Effects on Poly Aromatic Hydrocarbons Emission and Recycling Strategies. Fuel 2024, 357, 129379. DOI: 10.1016/j.fuel.2023.129379
3. Stellman, S. D.; Guidotti, T. L. Polycyclic Aromatic Hydrocarbons. Chemosphere 2007, 1240–1250. DOI: 10.7916/D8J38R96
4. Alamin, A.; Samara, F.; Al-Tamimi, A. K. Environmental Risk Assessment of Sustainable Concrete Through the Chemical Composition of Metals and Polycyclic Aromatic Hydrocarbons. Sustainability 2024, 16, 9237. DOI: 10.3390/su16219237
5. IARC—International Agency for Research on Cancer. https://www.iarc.who.int/ (accessed 08-02-2025).
6. LeMasters, G. K.; Genaidy, A. M.; Succop, P. et al. Cancer Risk among Firefighters: A Review and Meta-Analysis of 32 Studies. J. Occup. Environ. Med. 2006, 48, 1189–1202. DOI: 10.1097/01.jom.0000246229.68697.90
7. Li, A. J.; Feldman, S. M.; McNally, R. K. et al. Distribution of Organohalogen and Synthetic Musk Compounds in Breast Adipose Tissue of Breast Cancer Patients in Ulster County, New York, USA. Arch. Environ. Contam. Toxicol. 2019, 77, 68–78. DOI: 10.1007/s00244-019-00621-0