Cruise Ship Ultrafine Particles Promote Inflammation and Viral Replication, Study Finds
核心洞察
University of Southampton researchers identified a distinct air pollution signature from cruise ships burning fuel in ports, with ultrafine particulate matter enriched in vanadium, nickel, and cobalt.
Lab tests on human lung cells showed that exposure to these particles increased inflammatory gene expression and suppressed antiviral responses, facilitating replication of rhinovirus and SARS-CoV-2.
Vanadium, the most enriched trace element in the emissions, was found to directly diminish the ability of cells to prevent viral replication, with potential implications for infection severity and spread.
Air pollution from cruise ships may be damaging the health of people living in port cities by increasing inflammation and weakening cellular defenses against viral infections, according to new research from the University of Southampton published in Environment International.
The study provides the first in-depth investigation of the composition and toxicology of particulate matter within a busy port, revealing that ultrafine particles enriched with trace elements from shipping fuel combustion can penetrate deep into the lungs and potentially enter the bloodstream. These particles, the researchers found, are essentially unregulated and generally not monitored.
"In this research we've identified a clear air pollution 'signature' coming from cruise ships burning fuel in ports," said Matthew Loxham, Professor of Respiratory Biology and Toxicology and senior author of the study. "The ultrafine particles contained in these ships' emissions can penetrate deeper into the lungs than larger sizes of particulate matter, and may be able to enter the bloodstream, but particles of this size are essentially unregulated, and generally not monitored. We found that exposure of cells to these particles, and vanadium – the most enriched element in the particles – was both pro-inflammatory and facilitated the replication of viruses."
Source Identification and Seasonal Patterns
The research team selected five sampling sites around Southampton's port area, including a dock gate used for heavy goods vehicle movement, a container ship terminal, and a busy cruise terminal. A comparison site situated 5 km away from the port provided benchmark readings. Samples were collected during late spring and early summer, as well as during the winter off-season when fewer cruise ships visit.
At the cruise terminal, concentrations of vanadium, nickel, and cobalt in fine and ultrafine particulate matter were markedly higher during the busy summer season compared to the quieter winter months. These trace element concentrations were also generally elevated across the port relative to the comparison site.
Dr. Nat Easton, lead author of the study, noted: "We see increases in concentration when the wind was coming from the direction of the cruise ships, and when cruise ship presence was higher. The higher concentrations at the cruise terminal than the rest of the port is perhaps due to increased emissions from 'hoteling' cruise ships compared to cargo ships, but difference in fuel origins and berth occupancy times may also play a role."
Mechanisms of Cellular Damage and Viral Susceptibility
Laboratory experiments using lung lining cells demonstrated that exposure to ultrafine particulate matter collected from the cruise terminal during the summer season led to increased expression of genes associated with inflammatory responses and decreased expression of antiviral response genes.
Further investigation focused on vanadium, the most enriched trace element in the ship emissions. Researchers infected bronchial epithelial cells from the lungs of healthy donors with human rhinovirus — the virus responsible for the common cold (搜索) and a leading cause of hospitalizations following asthma (搜索) attacks — and also employed a model of COVID-19 (搜索) coronavirus infection.
"When exposed to vanadium, the number of copies of both viruses increased, indicating vanadium's role in diminishing the ability of cells to prevent viral replication," Professor Loxham explained. "This has potential implications for the severity and spread of infection."
Policy Implications and Recommendations
The findings lend weight to calls for reducing emissions from ships in populated areas. The researchers advocate for the adoption of shoreside power from clean energy sources, carefully selected alternative fuels, and improvements in emissions reduction technology. They also emphasize the need for increased monitoring of ultrafine particulate matter and its health impacts to inform regulation and better protect populations living near ports worldwide.
The study was funded by the Biotechnology and Biological Sciences Research Council (BBSRC), Leverhulme Trust, Medical Research Council (MRC), National Institute for Health and Care Research (NIHR) Southampton Biomedical Research Centre, the Southampton Marine and Maritime Institute, and the Southampton Institute for Life Sciences.