Secrets of your Cruise: Channel 4 Dispatches

Category: News Release

Every year 1.9 million people in the UK go on a cruise, Channel 4 Dispatches investigates the negative impact that cruising can have on the environment and the health of passengers.


  • Ultra-fine particulate air pollution in some areas of cruise ships found to be DOUBLE that of central London.
  • Heavy Fuel Oil, used by large ships, is legally permitted to contain 3,500 times more sulphur than is allowed in road fuel.
  • Environmentalists claim one cruise ship emits as much particulate matter every day as 1 million cars.


UK passenger numbers on cruises have risen by 60% in the last decade. With 448 cruise liners in operation around the world, the industry is worth an estimated £91 billion.

Dispatches went undercover on P&O Cruises, Britain’s most popular cruise operator. P&O Cruises’ owner, Carnival Corporation & PLC, claims that it is a ‘responsible global citizen’ with one former executive claiming, “We are committed to protecting the environment, particularly the marine environment where our vessels sail every day.”

Dispatches travelled on P&O Cruises’ ship Oceana, which is over 250m long, 15 storeys high and can carry more than 2,000 passengers.

Cruise Ship Emissions:

Outside of territorial waters cruise ships are subject to fewer environmental regulations. Using an infra-red camera, which allows us to see gases that aren’t visible to the naked eye, it is clear to see that there is a strong, continuous plume of gases coming from the main funnel of the ship.

The camera mostly detects Carbon Dioxide, one of the main contributors to climate change.


  • Carnival Corporation & Plc’s own figures for 2015 show that across its fleet the equivalent of just over 10 million tonnes of CO2 was released into the atmosphere.


Dispatches investigates whether cruise ships could also be damaging to your health. Among scientists there is growing concern around particulates that cruise ships emit as a by-product of burning fuel. Some of these particles are so small that they can’t be seen under a microscope. These ultra-fine particles are thought to penetrate the deepest into our bodies, to enter into the bloodstream and our organs.

Dr Matt Loxham, a leading expert in the impact of air pollution caused by shipping on human health at Southampton University said, “The ultra-fines are a special set of these particles. They’re about a thousandth of the width of a human hair. Larger particles that we inhale usually get trapped in the airways by our, the phlegm that’s in our airways or by hairs in the nostrils for example. But ultra-fines can get right into the depths of the lung and distribute throughout the body.”

On land there are legal limits on the levels of larger particles permitted in the air, but despite growing fears about the potential impact of ultra-fine particulates on our health, they are completely unregulated..

Using a P-Trak ultrafine particle counter, a piece of scientific equipment used to measure the number of ultra-fine particulates suspended in the air, Dispatches recorded:


  • 38,400 ultra-fine particulates per cubic centimetre in Piccadilly Circus
  • 84,000 ultra-fine particulates per cubic centimetre on the deck downwind of, and directly next to, the Oceana’s funnels, double the average found in Central London.
  • An average of 4,285 ultra-fine particles per cubic centimetre on the beach at Camber Sands, East Sussex.


Dr Loxham said, “It’s clear from your results that there are some areas of the ship deck that are affected by really quite high levels of particulate matter… Now these are levels you would expect to see in some of the most polluted cities in the world. Shanghai, Delhi and so on…”

When asked about the potential impact on passengers on board, he said, “Short term exposure has been shown by some studies to cause increased respiratory symptoms. In people who are asthmatic for example, that might give them a wheeze. Similarly for people with cardiovascular disease there’s thought to be exacerbation of certain cardiovascular symptoms.”

Impact on the environment from Heavy-Fuel usage:

John Maggs, president of The Clean Shipping Coalition, a global environmental organisation, said, “Most large ships burn Heavy Fuel Oil, it’s a residual product from the refining industry, so after the refiners have produced the petrol and diesel we put in our cars they’re left with what is essentially a waste product. It’s called residual fuel, or Heavy Fuel Oil.

From an environmental point of view, it’s very bad because of the very high sulphur content resulting in lots of air pollution problems. The shipping industry, however, have traditionally liked it because it’s much cheaper than other fuels.”


  • Heavy Fuel Oil is legally permitted to contain 3.5% sulphur, which is 3,500 times more sulphur than is permitted in road fuel.


Modern cruise liners can switch between different fuels mid journey. In places where regulations are stricter, such as EU ports or waters, they can turn to more refined fuel.


  • Even this cleaner diesel, capped at 0.1% sulphur is allowed to contain up to 100 times more sulphur than road fuel.
  • Carnival Corporation & Plc’s own statistics show that in 2015, 78% of the fuel used by its fleet was Heavy Fuel Oil – and this figure is rising year on year.


Daniel Rieger, Transport Policy Officer, NABU, said, “Ships cause not only greenhouse gas emissions, but also Sulphur Oxides, Nitrogen Oxides and particulate matter. Per day one cruise ship emits as much particulate matter as 1 million cars. You can say that kind of 30 cruise ships pollute as much as all the cars in the United Kingdom.”

The industry body Cruise Lines International Association has previously said that the industry has “invested significantly over the last decade to develop new technologies to help reduce air emissions.”

The rules which ships follow at sea are set by the International Maritime Organisation. It’s now agreed to reduce the maximum sulphur content allowed in marine fuels from 3.5% down to 0.5% in 2020 – bringing an end to the use of Heavy Fuel Oil.

John Maggs said, “It’s a very significant gain for the environment and public health. But it still leaves the shipping industry with fuel that’s hundreds of times more polluting than the fuel we put in our cars.”

Sewage dumping:

Maritime regulations allow treated sewage to be dumped into the sea as long as the ship is more than three nautical miles from shore. Beyond twelve miles even raw sewage can be dumped.

Grey water, which is wastewater from domestic areas such as showers, sinks, washing machines and dishwashers, although there are local regulations there are no global regulations despite the fact it can contain pollutants such as cooking oil, detergents, soaps and food waste. Grey water is believed to have similar environmental impacts to sewage. It would be illegal to dump it in rivers on land, but not at sea.

Most cruise lines are signed up to a code of practice preventing grey water from being discharged within 4 nautical miles of shore or when a ship is stationary – as well as agreeing to some basic sewage treatment.


  • A 3,000 passenger cruise ship will dump approximately 643,000 litres of grey water and 79,000 litres of sewage every day.


Dr Simon Walmsley, WWF Marine Manager, said, “We believe that dilution is not the solution to pollution. We think that more research is needed in terms of the impacts, particularly in the shipping lanes where the discharges are occurring in the same place. It can cause deoxygenation, and we are seeing increased numbers of dead zones – this may well be linked to sewage discharges.”

Some ships do now have Advanced Water Treatment Systems – meaning that both grey water and sewage can be processed more thoroughly before being discharged.


  • However, industry figures suggest that only half of ships built in the next decade will have this technology.


Pollution in port:

London’s first ever cruise terminal is being built, near Greenwich, called Enderby Wharf. It will be a single cruise berth, big enough for a 230m long ship, carrying 1,600 passengers.

When at berth, cruise ships continuously run their engines to generate electricity on board – this is known as ‘hoteling’. A single ship requires the same amount of power as a small town.

Some residents are concerned about the impact these ships’ air emissions will have on air quality in the area, which has already been designated an Air Quality Management Area because of its air pollution problems.

The Royal Borough of Greenwich has said that it has put in place measures to ensure robust monitoring of air quality, adding that Enderby Wharf will see the creation of jobs, boost tourism and benefit the local economy.

Response from Carnival Corporation and Plc:

In response to Dispatches' discoveries on board the Oceana, P&O Cruises told us: “Since 2005 we have reduced our fuel consumption by… 28% with the accompanying reduction in air emissions.”

They said the Oceana will be fitted with an: “Exhaust Gas Cleaning Systems…” Which are: “installed on 60 ships across its brands… This action significantly improves the quality of air emissions… Soot and particulate matter reductions in excess of 80% have been achieved.”

They said in 2014 they had reduced: “CO2e emissions… by 20 percent…” And: “Has renewed its goal to continue reducing the rate… The health, safety and welfare of our guests & crew across all our ships is our absolute highest priority… we recognise that there is a public interest… related to particulate matter and related health issues”.

And they are carrying out: “Similar studies… and… will share these results with the industry in order to understand and execute best practice”.


Prod/Dir: Ben Laidlow

Series Prod: Andy Lee

Exec Prods: Chris Shaw, Adam Vandermark

Prod Co: ITN Productions