There are calls for the cruise ship industry to be effectively regulated to minimise the serious risk it poses to human health.
Cruise ships are a potential source of human health risks to passengers, staff and land-based residents who live near ports or work in shipyards, according to researchers.
This includes the spread of infectious diseases, such as the outbreaks of Covid-19 on some cruise ships.
Experts also found there was an impact from noise and air pollution on health as well as difficult working environments for boat and shipyard staff.
The international research team found cruising was a major source of environmental pollution and degradation, with air, water, soil, fragile habitats and wildlife affected.
They combined evidence from more than 200 research papers on the health of people and the environment in different oceans and seas around the world.
Professor Lora Fleming, of the University of Exeter, said: “Cruise tourism was rapidly expanding pre-Covid-19, and our research shows it causes major impacts on the environment and on human health and wellbeing.
“We need much better monitoring to generate more robust data for the true picture of these impacts.
“Without new and strictly enforced national and international standardised rules, the cruise industry is likely to continue causing these serious health and environmental hazards.”
First author Dr Josep Lloret, of the University of Girona, said: “Our paper highlights that cruising is a prime example of how the fates of our health and our environments are intertwined.
“Up until now, most studies have looked at aspects of this in isolation.
“Our review is the most comprehensive to date to combine these research fields and take a holistic view of how cruising damages our environments and our health.
“We now need global legislation to minimise damage on both our oceans and our health.”
The review combined research papers on a range of factors which have environmental or health impacts, or both.
Research suggests a large cruise ship can have a carbon footprint greater than 12,000 cars.
Passengers on an Antarctic cruise can produce as much CO2 emissions while on an average seven-day voyage as the average European in an entire year.
Within the Mediterranean, cruise and ferry ship CO2 emissions are estimated to be up to 10% of all ship emissions.
The paper also includes research on solid waste as an example of an activity from cruise ships which affects both health and environment.
While cruise ships make up only a small percentage of the global shipping industry, it is estimated that around 24% of all waste produced by shipping comes from this sector.
Co-author Dr Hrvoje Caric, of the Institute for Tourism in Croatia, said: “We’ve long known that cruise ships cause damage to the environment. However, it’s hugely important to incorporate the impact on human health into that picture.”
– The article, Environmental and Human Health Impacts of Cruise Tourism: a Review, is published in the journal Marine Pollution Bulletin.