Air pollution generated by cruise ships in port cities may exacerbate viral infections by driving lung inflammation and suppressing antiviral defenses, according to new findings from the University of Southampton. This research highlights the role of ultrafine particulate matter (PM)—particles smaller than one thousandth the diameter of a human hair—and their enriched metal content in promoting viral susceptibility.
For the first time, the team conducted an in-depth chemical and toxicological analysis of PM from various locations around Southampton’s busy port, including a cruise terminal active in peak and off-season periods. Their findings revealed elevated levels of vanadium, nickel, and cobalt trace elements in ultrafine particles at the cruise terminal during the summer peak, coinciding with increased cruise ship activity. These metals were less concentrated at a reference site 5 km away, identifying cruise ships as a primary emission source.
Ultrafine particles are particularly concerning because of their capacity to penetrate deep into the respiratory tract and potentially enter the bloodstream. Laboratory tests using human lung epithelial cells demonstrated that exposure to these particles triggered increased expression of pro-inflammatory genes while suppressing antiviral gene expression. Importantly, vanadium emerged as a key driver of this effect.
Further experiments involving infection of bronchial cells with human rhinovirus—the primary cause of the common cold—and a model coronavirus showed that vanadium exposure significantly amplified viral replication. These results indicate that vanadium-containing particulate pollution can weaken the lung’s cellular defenses, possibly worsening the severity and transmissibility of respiratory viral infections including COVID-19.
The study underscores the urgent need for regulatory attention to ultrafine particulate matter from ship emissions, which currently escapes systematic monitoring and control. The authors advocate for measures such as implementing shoreside power from cleaner energy sources to reduce emissions during port stays, exploring alternative low-emission fuels, and enhancing pollutant filtration technologies aboard vessels.
These findings hold significant implications for the health of populations residing near port cities globally, where cruise ship traffic continues to grow. By unveiling the mechanistic link between shipborne ultrafine PM and increased viral susceptibility, this research provides critical insight into environmental factors influencing respiratory infectious disease outcomes.
Published in the journal Environment International, the study was funded by UK research councils and institutes including the Biotechnology and Biological Sciences Research Council and the Medical Research Council. The authors emphasize that mitigating pollution from maritime sources should be integrated into public health strategies aimed at combating viral pandemics and reducing respiratory disease burden.
Subject of Research: Air pollution from cruise ships and its impact on respiratory viral infections
Article Title: Ultrafine particulate matter emitted from ships drives inflammation and susceptibility to viral infection
News Publication Date: 10 July 2026
Web References: https://www.sciencedirect.com/science/article/pii/S0160412026003399
Image Credits: University of Southampton
Keywords
Air pollution, ultrafine particulate matter, cruise ship emissions, vanadium, viral infection, inflammation, respiratory health, COVID-19, rhinovirus, environmental health
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