Arctic Shipping · Air Quality

Ten Days with a Particle Counter in Ilulissat

Screening measurements in the port of Greenland’s third largest town averaged 60,000 to 70,000 ultrafine particles per cubic centimetre, with peaks above 200,000. The Arctic background can fall below one hundred. The figures are not peer reviewed. They are also not a surprise.

By SEVENSEAS Media | Ocean Conservation

For ten days at the end of July and the beginning of August, a Danish air quality specialist walked the port of Ilulissat carrying a handheld particle counter. The instrument does one thing: it reports how many particles are suspended in each cubic centimetre of air passing through it. In the harbour the readings settled at averages between 60,000 and 70,000, and at moments climbed past 200,000. For context, the same researcher has published measurements from a windy day in another Greenlandic town where the average was 72.

The measurements were released on 12 August by the Clean Arctic Alliance, a coalition of twenty-four non-profit organisations campaigning on Arctic shipping. They were taken between 29 July and 7 August 2026 by Dr Kåre Press-Kristensen, senior advisor on air quality and climate at Green Global Future, one of the coalition’s member groups.

According to the release, the particles counted were predominantly ultrafine, meaning smaller than 100 nanometres across, and carried a high content of soot, or black carbon. That combination matters twice over. Ultrafine particles are small enough to cross from the lung into the bloodstream. Black carbon is also a short-lived climate pollutant, and when it settles on Arctic snow and ice it darkens the surface and accelerates melting.

Press-Kristensen reports that exposure was highest when the wind carried port air towards the residential parts of town, which is where the finding stops being a technical curiosity. Ilulissat is not a large industrial city where a harbour sits at a distance from housing. The port is part of the town.

What the WHO comparison actually says

The press release frames its headline number against a World Health Organization figure of 1,000 particles per cubic centimetre, making Ilulissat port roughly 60 to 70 times higher. The comparison is real but the framing needs care, and the precise version is arguably more damning than the loose one.

The WHO’s 2021 global air quality guidelines do not set a guideline level for ultrafine particles at all. The organisation says explicitly that numerical guideline levels cannot be established for them in the absence of clear quantitative evidence on their independent health effects. What it issues instead is a good practice statement, which describes concentrations below 1,000 particles per cubic centimetre as low, and concentrations above 10,000 as high, both as twenty-four hour means, with 20,000 as the high threshold over one hour.

So 1,000 is not a safety limit that Ilulissat exceeds. It is the point below which the WHO considers particle counts unremarkable. The number that carries more weight is the other one: at 60,000 to 70,000, the port averages sit six to seven times above the level the WHO itself calls high, and the peaks sit ten times above it.

The baseline is what makes the number stark

Greenland has some of the cleanest ambient air anywhere. That is the finding of a peer-reviewed study published in Atmospheric Pollution Research in 2018, co-authored by Press-Kristensen with colleagues at the Technical University of Denmark, which measured ultrafine particles in the town of Sisimiut and two nearby settlements. On windy days the average fell to 72 particles per cubic centimetre.

The same study found that local combustion sources swamped that baseline entirely. Beside a road at the Sisimiut harbour the average reached 77,009. During one aircraft landing and departure at Sisimiut airport it was 44,741. Heavy machinery passing the instrument pushed a reading to 270,993, which fell back to 1,180 within ten minutes of the vehicle moving on. Flue gas inside the town’s waste incineration plant measured up to 334,976.

The Ilulissat screenings sit squarely inside that published pattern. Neither set of figures describes a place with a general air pollution problem. Both describe places where the air is close to pristine until you stand next to something burning diesel, and then it is not.

The ships at berth

The release singles out cruise ships, which run their engines through the day while berthed or at anchor to supply power to the vessel, and states that a large cruise ship emits as much toxic air pollution as 3,000 to 5,000 cars per second. That comparison should be read as an illustration rather than a measurement. No method is given for it, and the unit as written does not parse. SEVENSEAS has asked the Clean Arctic Alliance for the underlying calculation.

The underlying point does not rest on that figure. Cruise traffic has a documented effect on Arctic air quality: a 2013 study in Atmospheric Chemistry and Physics separated measurements at Ny-Ålesund and Zeppelin Mountain on Svalbard by whether cruise ships were present in the fjord, and found elevated sulphur dioxide, particle and black carbon concentrations when they were. The mechanism in Ilulissat is the same one, at closer range, with houses upwind or downwind depending on the day.

What is being asked for

The remedies in the release are unglamorous and specific: electrify the equipment that works the quayside, and install shore power so that vessels at berth can switch their engines off and draw electricity instead. Greenland has the generating capacity to make that plausible.

Greenland and other Arctic nations have a great potential to produce pollution free renewable electricity, and to cut both air pollution and their dependence on fuel prices fluctuating with the situation in the Middle East. Electrification of port equipment and onshore power for vessels are also important steps to consolidate fishing and export of seafoods.

Dr Kåre Press-Kristensen, Green Global Future

Shore power addresses ships in port. It does nothing about ships at sea, and for those the release argues for a fuel switch: away from residual heavy fuels and towards distillates such as marine gas oil, the category increasingly discussed at the International Maritime Organization under the label of polar fuels. Greenland-flagged vessels already run on marine gas oil.

The expense of electrification of ports will be recouped through fuel oil savings. This will eliminate local pollution from ships at berths, improve public health in the wider vicinity and reduce global warming.

Dr Kåre Press-Kristensen, Green Global Future

That last claim is his, and it is not accompanied by a costing. Shore power requires substantial capital spending on grid connections, transformers and quayside infrastructure, and the payback depends on how many vessel calls a port handles and at what price electricity is sold. Whether it pays for itself in Ilulissat specifically is an open question, and worth asking of Greenland’s port authorities rather than assuming.

Alongside those measures the release asks Greenland to keep backing the polar fuels proposal at the IMO, to ban the discharge of scrubber wastewater in its territorial seas as OSPAR has recommended and other Nordic countries have done, and to establish a green shipping corridor between Nuuk and Reykjavik.

The regulatory gap

A great deal has changed in Arctic shipping regulation over the past two years, and almost none of it touches black carbon. That is the argument the Clean Arctic Alliance’s lead advisor makes about the newest and largest measure of all.

The Northeast Atlantic Emission Control Area is a welcome step towards reducing emissions of air pollutants SOx and NOx, but it will not adequately address black carbon emissions which lead to climate heating in the Arctic. Ships can still use traditional heavy fuel oils in combination with scrubbers or ultra low sulphur fuel oils to comply with the sulphur requirements, but which emit high levels of black carbon.

Dr Sian Prior, Lead Advisor, Clean Arctic Alliance

The polar fuels proposal she wants adopted instead is co-sponsored by Denmark, Germany, France and the Solomon Islands. It is not yet agreed. The next substantive opportunity to advance it is the IMO’s Pollution Prevention and Response sub-committee, which meets in early 2027, and the Alliance is pressing for the regulation to apply across the full area used by the Arctic Council’s Arctic Monitoring and Assessment Programme, on the grounds that black carbon emitted well to the south still ends up on Arctic ice.

Heavy fuel oil, and how little has been won

The IMO’s ban on the use and carriage for use of heavy fuel oil in the Arctic came into force on 1 July 2024. Two years on, its reach remains limited. Exemptions and waivers mean it will not be fully in place until July 2029, and even then it applies only to waters where sea ice may be encountered. On the commercial side, the Greenlandic shipping firm Royal Arctic Line announced in May 2025 that it would stop using heavy fuel oil.

The scale of what is left is set out in Black Carbon Emissions from Ships in the Arctic 2019 to 2024, a report by Energy and Environment Research Associates commissioned by the Clean Arctic Alliance. Across the five years it covers, black carbon emissions from Arctic shipping rose by 47 percent. Inside Polar Code Arctic waters they went from 259 to 759 tonnes. Across the broader band north of 60 degrees they rose from 2,696 to 3,310 tonnes, and within the AMAP boundary from 1,704 to 2,487 tonnes. The report also estimates that fully enforcing the heavy fuel oil ban would cut black carbon by somewhere between 2 and 5 percent.

That last figure is the one to sit with. It is the measure of how much of the Arctic’s shipping soot problem the headline regulation of the past decade actually solves.

Why the timing matters

Ilulissat is about to get much busier. Its expanded airport, with a runway long enough for jet aircraft, is due to open in October 2026, and a direct route to Copenhagen is scheduled to begin on 29 October. Greenland currently receives in the order of 130,000 visitors a year, a large share of them arriving by ship.

There is an irony in the Sisimiut data worth noting here. The single highest transient reading in that study came from heavy machinery, and one of the highest sustained ones from an aircraft landing. More aircraft, more construction and more vessel calls all point the same direction. The measurements from this summer are a baseline taken weeks before the town’s access changes, which makes them more useful than they would otherwise be, and makes the absence of a permanent monitoring station in Greenland’s ports harder to justify.

Ten days of readings from one harbour do not settle anything. They do establish that the question is worth measuring properly, in more than one port, over more than one season, by someone without a position to advance. On present arrangements, nobody is.

The full report, Black Carbon Emissions from Ships in the Arctic 2019 to 2024, was prepared by Energy and Environment Research Associates for the Clean Arctic Alliance and is available at cleanarctic.org. The Ilulissat measurements are screening data released by the Clean Arctic Alliance on 12 August 2026 and have not been peer reviewed.

SEVENSEAS Media · Conservation Journalism for the Ocean