Ship Emissions: Monitoring, Enforcement and Human Health


Air pollution from shipping vessels poses a serious problem that is not given much importance today but gradually the scenario is shifting towards a positive direction where guidelines and rules set forth by various organizations are garnering much-needed attention. 


What is air pollution?

Air pollution occurs due to the presence of undesirable solid or gaseous particles in the air in quantities that are harmful to human health and the environment.  It can be defined as the presence of foreign matter either gaseous or particulate or combination of both in the air which is detrimental to the health and welfare of human beings.

How does the shipping industry contribute to air pollution?

Consider the example of Europe where an estimated 80,000 ships visit the European ports each year for trade and commerce.  The majority of the ships use cheap low-quality fuels when burnt give out sulphur, nitrogen, oxides and particulate matter.  This cheap fuel which is thick, dirty and has a tar-like consistency is the remaining component after crude oil has been refined to obtain petrol and petroleum by-products.

It is estimated that millions of tonnes of chemical exhausts are emitted by the ships which are the main contributors to lung diseases, heart diseases, and cancer.  It is reported to be the cause of 50,000 human deaths per year in Europe, from this estimate we can derive that air pollution is a serious problem that needs a solution.  The emission given out by the ship’s affect the climate and modify the atmospheric chemistry  of the ocean as well and leads to ocean acidification which can gradually destroy the marine habitat by making the ocean turn acidic.  The humans who work on ships, ports and harbours are adversely affected by air pollution.

How do we reduce the impact of air pollution?


The IMO (International Maritime Organization) in January 2015 introduced new regulations to reduce the impact of harmful emissions.  These regulations are aimed to bring down the open-ocean emissions of sulphur dioxide (SO2) from the current level of 3.5% of the total fuel mass to 0.35% by 2020.


Near the coast, the IMO has designated Sulphur Emission Control Areas (SECAs) which includes the English Channel and the surrounding European waters where the sulphur content must drop to 0.1% by 2015.  Compliance with above-mentioned regulation will add thousands of dollars per day to the fuel bill of each ship but in the long run, will benefit the environment immensely.  Few of the global shipping companies have implemented this regulation but there are more companies that fail to implement this regulation to avoid extra bills which have resulted in these ships failing the emission test upon entry into the port.

Reference point for impending emissions:

Continuous atmospheric measurements at the Penlee point Atmospheric Observatory (PPAO) are conducted by researchers at Plymouth Marine laboratory; they have taken up this opportunity to assess the success of IMO regulations.  The western side of the English Channel, a busy shipping lane has been designated as the SECA and also a PPAO site. Measurement collection started seven months before the 2015 regulations set forth by IMO came into force, these measurements are considered as the reference point for impending changes in emissions.

The PPAO as part of the NERC funded western channel observatory is operated by Dr. Tim Smyth, Dr. Mingxi Yang, and colleagues.  The team expressed that the data provided to them was clear and precise.  Mr Yang added, “We found that the SO2 mixing ratio in south-westerly winds from the Atlantic was generally low and showed a daily cycle that is largely consistent with dimethyl sulphide oxidation – a naturally occurring part of the sulphur cycle over the ocean”.  Yang further explains, “When analyzing emissions carried by south-easterly winds from the Channel things were quite different; they were elevated and SO2 mixing ratios were more variable.  We interpret this being due to an additional contribution from ships, which were far more numerous in that part of the English Channel.  In 2015, we witnessed a threefold reduction in this ship contribution compared to 2014, suggesting a high level of compliance (>95%) with the IMO regulations for ships near Plymouth.”

Smyth says, “We are working with industrial partners to develop an on-ship monitor that will link with the tracking system used on ships to report back ship identity, position and emissions composition to ground stations for scrutiny and hopefully avoidance of non-compliance by the ship’s operator.  It’s an excellent example of science becoming relevant to a real-world challenge.”

Smyth is keen on applying the technology to ensure compliance with the pollution regulations.

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Source: NERC