Water discharge resulting from spraying in the ship's exhaust with water and rinsing it back into the sea. This is highly acidic wastewater that has heavy metals and Polycyclic Aromatic Hydrocarbon (PAHs).  

 Grey water describes wastewater that has been collected from a ship's galley, showers, laundries, and sinks.  Grey water contains microplastics from laundry and personal care and cosmetics. Grey water can also contains bacteria, viruses, and other harmful chemicals.

 Sewage discharge that contains pollutants including nutrients, metals, toxins and pathogens. Blackwater discharges impair water quality, negatively affect aquatic ecosystems and increase risks to human health. 

 Bilge water can contain concentrations of various industrial fluids from the ship's machinery spaces such as coolant, lubricants, and fuel. 

There are tons of solid waste on cruise ships. This includes paper, plastic, cardboard, food, cans, glass, and more. 

Carbon dioxide (CO2) is an important heat-trapping gas, also known as a greenhouse gas, that comes from the burning of fossil fuels for propulsion and power generation.

Breathing in Sulfur dioxide causes irritation of the nose and throat and exasperates respiratory conditions like asthma and emphysema. 

 Black carbon is the second most important contributor to global warming. The fine particulate is linked to respiratory and cardiovascular diseases.

 NOx can irritate airways in the respiratory system and aggravate respiratory diseases, particularly asthma, leading to respiratory symptoms (coughing, wheezing or difficulty breathing), hospital admissions and visits to emergency rooms.

A greenhouse gas 28 times as potent as CO2. Falsely claimed to be a clean source of fuel for new cruise ships.