Researchers from the Hong Kong University of Science and Technology (HKUST) have recently proved that apart from protecting us from inhaling respiratory droplets that contain pathogens, surgical masks are also effective in blocking airborne carcinogens, reducing cancer risks such as lung cancer and leukemia.
The team, led by Associate Prof. Wan CHAN and Prof. Jianzhen YU from the Department of Chemistry and Division of Environment and Sustainability at HKUST, found that in addition to virus-carrying droplets, face masks could also efficiently trap a wide range of Polycyclic Aromatic Hydrocarbons (PAHs) compounds, including its most toxic forms, in ambient air.
While the cancer-causing PAHs – sized three-ring or above, could be 8,000 times smaller than the respiratory droplets produced by sneezing[1], the team found that ASTM Level 1 face masks with a BFE (bacteria filtration efficiency) of ≥ 95% can block up to 70% of the compounds. The filtration rate further jumps to almost 75% with ASTM Level 2 or Level 3 masks with BFE of ≥ 98%, indicating that wearing a face mask could potentially reduce cancer risks associated with such airborne carcinogens by up to 70%.
PAHs are generated by combustion processes, such as vehicle emission, cigarette burning, and incense burning, and are ubiquitous in the atmosphere. Inhalation exposure to PAHs has been proven by years of scientific research to have close ties with the development of lung cancer and leukemia. It is crucial to monitor personal exposure to ambient PAHs for cancer risk assessment and management.
