Air quality control in ports, improving the image and management of a maritime port

March 9, 2024
Air quality monitoring in ports - Kunak

Table of contents


  • Maritime transport is an essential asset for the European economy.
  • Cruise travel has become an important source of income in many coastal cities.
  • The main ship emissions are SO2, NOx, suspended particles and noise.
  • Real-time monitoring of air quality using low-cost sensors presents itself as one of the most efficient measures.

Maritime and river ports are essential infrastructures for the economy of the countries. They create employment opportunities and boost the economy through the transport of goods, logistics operations, fishing and, in later years, cruise travel.

However, all that frantic activity has a hidden side: the air pollution caused by ships. Therefore, the measurement of air quality at ports is a point of interest. And this is not only due to issues of environmental quality but also because of the way the public image is improved by those port authorities who opt for this solution.

Port activity: brief contextualisation of the industry

According to Martin Dorsman, ECSA Secretary General, maritime transport is ‘one of the most valuable assets in Europe‘. Thus, data from 2018 indicate that it directly contributed 54,000 million Euros to the European GDP. Likewise, it provided jobs for around 2 million people through direct or indirect employment.

However, since a few years ago, one of the activities with the highest growth is related to holiday cruises, and not just in the number of operations. Both the routes available and the passenger numbers have increased significantly (1). So much so that Spain exceeded 10,000,000 passengers in 2018, a figure which represented an inter-annual increase of 9.66 %.

The graph below shows the fifteen Spanish ports with the highest number of cruise passengers during 2017 and 2018 (2):

What does this vibrant cruise traffic translate into? Into a source of income which, for example, in Catalonia, exceeded 1,000 million Euros (data from 2016). This figure represents a turnover of €518 per passenger, according to the newspaper La Vanguardia in January 2018.

Infographic: How Cruise Ship Pollution Compares To Cars | Statista

You will find more infographics at Statista

Air quality at ports, what impact do ships have?

However, one of the handicaps for maritime traffic is the reduction in air quality, caused by the type of fuel used by ships. According to a Transport & Environment Report, in 2017, just in Europe, 203 cruises «released around 62 kt of SOx, 155 kt of NOx, 10 kt of PM and more than 10 Mt of CO2».
El transporte marítimo es crucial para el comercio global, pero su impacto en la calidad del aire es notable. Los buques emiten óxidos de azufre (SOx), óxidos de nitrógeno (NOx) y partículas en suspensión (PM), que afectan la salud humana y el medio ambiente. Estas emisiones contribuyen a enfermedades respiratorias, lluvia ácida y problemas cardiovasculares. Además, el ruido subacuático afecta la fauna marina. Proyectos como CORE LNGas hive y OPS Master Plan buscan reducir estas emisiones mediante el uso de combustibles más limpios.

Real-time air quality monitoring is an efficient measure to manage this impact. In addition, port activity is vital to the economy, generating employment and boosting the economy through freight transport and cruise tourism. However, it is important to balance economic activity with the protection of the environment and public health.

Types of pollution generated by ships

Air quality in ports is an issue of growing concern due to the significant environmental impact of shipping and port activities. Ports are hubs of trade and logistics, but they are also sources of pollution that affect both the environment and human health. These are the main types of pollution that can be found in a port:

Nitrogen oxides (NOx):

Nitrogen oxides (NOx), which are emitted by internal combustion engines of ships and land vehicles, represent a significant environmental concern. These gases are associated with a variety of respiratory problems in humans and also contribute to global warming and the deterioration of aquatic and terrestrial ecosystems. The presence of NOx in the atmosphere can trigger chemical reactions that result in the formation of smog and acid rain, affecting the health of people and the integrity of our natural environments. Therefore, the management of these emissions is crucial to protect both public health and the planet’s biodiversity.

Sulphur oxides (SOx):

The burning of fossil fuels with high sulphur content by ships is a practice that has significant environmental and health impacts. The resulting sulphur oxides (SOx) are gases that can cause respiratory ailments in those exposed and are also precursors to acid rain. The latter has the potential to damage forests, lakes and buildings, as well as adversely affect aquatic life. In addition, SOx can reduce visibility, which affects the safety of maritime and land transport. Therefore, managing these emissions is crucial to protect human health and the environment.

Particulate matter (PM1, PM2.5, PM4 and PM10):

Particulate matter, known as PM1, PM2.5, PM4 and PM10, is a complex mixture of extremely small substances such as soot and ash. Their tiny size allows them to penetrate the innermost areas of the human respiratory system and from there into the bloodstream, posing a significant health risk. These particles originate from the combustion of various materials and are also a by-product of the removal of materials during port operations. Their presence in the air has serious consequences, including the development of cardiovascular and respiratory diseases in humans, as well as damage to local flora and fauna, disrupting the ecological balance of affected environments.

Noise pollution:

Noise pollution in port environments is an environmental and public health issue arising from multiple sources. Loading and unloading operations, together with general port activity, generate significant noise levels. Added to this is the constant circulation of vehicles and heavy machinery, as well as maritime traffic and the presence of passengers. This cocktail of noise not only stresses marine animals, altering their behaviour and natural habitats, but also has detrimental effects on human health, including hearing problems and psychological stress. Noise pollution management is therefore a crucial challenge for the sustainability of maritime activities and the quality of life of nearby communities.


Oil, often released into the marine environment through accidental spills or operational discharges from ships, represents a significant threat to the environment. These unfortunate events can result in the destruction of entire marine ecosystems, altering biodiversity and endangering countless species that depend on these habitats for their survival. In addition, coastal communities near such incidents are not exempt from risk, as they may face serious health problems due to contamination of seafood and water. Preventing such incidents and responding quickly and effectively when they occur are essential to protect our valuable marine resources and the health of human populations living near the sea.

This decline in air quality is not limited to port areas. Thus, while coastal cities such as Marseilles are recording an increase in cancer cases, suggesting a probable correlation, cities such as Gothenburg are observing NO2 levels from ships exceeding those from traffic near the port (3).

Esta merma en la calidad del aire no se limita a las zonas portuarias. Así, mientras ciudades costeras como Marsella registran un aumento en los casos de cáncer que sugiere una probable correlación, urbes como Gotemburgo observan cómo los niveles de NO2 procedentes de los barcos superan a las del tráfico en las zonas inmediatas al puerto (3).

Regarding suspended particles, for example, considered by the WHO a very harmful pollutant, it is worth mentioning the research by Ryan D. Kennedy, from Johns Hopkins University (4). In the framework of this study, measures were taken on various cruise liner decks. The results confirmed a high quantity of suspended particles generated by these ships. In some aft areas exposed directly to the emissions from the funnels, the concentrations were comparable to those found in cities such as Beijing, this being a significant problem even at sea.

These pollutants pose a risk to the marine and terrestrial environment and directly affect human health and the quality of life of port communities. It is therefore essential to implement stricter control measures and regulations to minimise the environmental impact of ports and promote sustainable practices in the maritime sector.

What activities generate pollution in ports?

Ports, vital for world trade, are also major generators of pollution due to various activities involved in their operation. These are some of the activities that have the greatest impact:

Loading and unloading operations

Loading and unloading operations are critical processes in transport logistics, but they involve environmental consequences. During these operations, the constant transport of goods emits harmful particles and gases into the air. These emissions include dust that can deteriorate local air quality, as well as greenhouse gases that have long-term implications, such as increasing global temperatures and altering weather patterns. These activities are therefore significant contributors to climate change, an environmental challenge we face globally.

Heavy vehicle traffic

Heavy vehicle traffic, especially trucks transporting goods, is a considerable source of air pollution. These vehicles emit nitrogen oxides and fine particulate matter that affect the air and directly impact the health of people living near the traffic routes. Inhalation of these substances can cause respiratory problems, from minor irritations to more serious conditions. Therefore, heavy vehicle traffic is not only a challenge for environmental management but also for public health.

Power generation and machinery use

Power generation and machinery used in ports are essential activities for maritime trade and industry. However, these processes have a negative side. Port equipment and ships at berth in port depend heavily on fossil fuels, a source of energy that, when burned, releases carbon dioxide (CO2) and a range of other pollutants into the atmosphere. These emissions contribute to the greenhouse effect, intensifying global warming, and are also responsible for the acidification of our oceans. This phenomenon alters the chemical balance of seawater, which can have devastating consequences for marine life and the ecosystems that depend on it.

Vessel maintenance and cleaning

The maintenance and cleaning of vessels are essential tasks to ensure the operability and safety of ships. However, these practices can have a dark side from an environmental point of view. When cleaning ships’ tanks and hulls, toxic substances are released into the aquatic environment. These often harmful chemicals are dispersed into the water, causing pollution of marine ecosystems and adversely affecting aquatic life. From habitat alteration to direct damage to the health of marine organisms, the impacts of these clean-up activities are significant and pose major challenges for marine conservation.

Port construction and expansion activities

Port construction and expansion activities are essential for the development of maritime infrastructure and economic growth. However, these civil works, including dredging, have a considerable environmental impact. By removing sediments from the seabed, previously deposited pollutants are released, and marine habitats are altered. The resulting turbidity of the water can have adverse effects on aquatic species, from reducing sunlight needed for photosynthesis to affecting feeding and reproduction processes. These human interventions require careful planning and management to minimise their impact on sensitive marine ecosystems.

These activities, in general, if not properly managed, can have long-lasting detrimental effects on the environment and human health. It is therefore essential to implement sustainable practices and clean technologies to reduce the environmental footprint of ports. Process optimisation and strict regulation are key to ensuring a greener future for the port industry.

Consequences of pollution in ports

The consequences of environmental pollution generated by port activity and maritime transport are multiple and worrying. In the first place, atmospheric pollutants such as nitrogen and sulphur oxides, as well as fine particles, deteriorate the quality of the air, which can cause respiratory and cardiovascular diseases in nearby populations. In addition, as mentioned above, noise pollution disturbs marine and terrestrial wildlife, affecting behavioural and reproductive patterns.

In addition, oil spills and other chemical spills damage marine ecosystems, killing flora and fauna and disrupting the food chain. Water pollution by heavy metals and other toxic substances has long-term effects on biodiversity and the health of aquatic ecosystems. Finally, the accumulation of pollutants contributes to climate change, exacerbating extreme weather events and raising sea levels, posing an additional risk to port infrastructures.

Port authorities must implement mitigation and control measures to reduce these negative consequences, thus ensuring a more sustainable future for the maritime industry and affected communities, as many ports have done thanks to Kunak’s environmental monitoring technology.

Air quality control in ports - Kunak

Air quality control in the port of Bilbao – Kunak

Solutions to reconcile economic growth and well-being

Decarbonisation and improvement in air quality at ports is an urgent task.  In this regard, one of the elements emerging more strongly is Green Ports. Their objective is to minimise the environmental impact on the atmosphere, marine resources, biodiversity, and inhabited areas nearby.

An essential measure within the framework of these sustainable ports is real-time, continuous atmospheric monitoring. The deployment of air-quality meters enables port authorities to:

  • Detect the presence of hot spots.
  • Establish alerts for high levels of contamination.
  • Adopt measures based on actual contamination information.

A practical example of the benefits brought about by this solution is the project that Kunak finished in cooperation with Labaqua for the Port Authorities in the Balearic Islands. This initiative has led to the deployment of 25 devices that monitor contamination levels and noise in different maritime ports on the islands.

Nevertheless, other methods have also been adopted to reduce the problem. One of the highest-impact decisions has been, without a doubt, the enforcement of a new standard related to sulphur oxide emissions. Decreed by the International Maritime Organisation and in force from 01/01/2020, it establishes a new limit on the contents of sulphur in fuel used in boats, from 3.5 % mass/current mass to 0.5 %. However, the answer for many shipping companies has been the installation of scrubbers or gas scrubbers. This alternative allows the same type of fuel to be used but reduces sulphur emissions. The problem is that, in many cases, surpluses are poured into the sea, which may put marine biodiversity at risk.

Furthermore, another measure being studied by ports such as Barcelona is the electrification of the docks. However, this is a long-term solution that, in the case of the Catalonian capital, will not begin to materialize until 2021.

Control de la calidad del aire en los puertos - Kunak

Air quality monitoring in the port of Dunkerque – Kunak

Ports already using Kunak’s technology

Air quality widget of the Balearic Islands Port Authority (Spain)

Information panel on air quality in the port of Palma de Mallorca, owned by Ports de Balears, with information provided by Kunak’s network of air quality stations.


Port activity is fundamental for the economy of coastal nations. Yet, many operations they perform compromise air quality. The emissions from boats are one of the main sources of conflict, but not the only one. What is the best way to identify the problem? Deploying low-cost air-quality sensors that make continuous, real-time monitoring possible.