Ultra-Fine Particles From Aviation May Impact Health, T&E Study Finds

Transport-focused environmental NGO Transport & Environment (T&E) is calling for better monitoring of ultra-fine particles (UFP), a non-CO₂ effect of aviation, following the publication of a report highlighting their potential impact on the health of people living near airports.

The study, commissioned by T&E and carried out by Netherlands-based environmental consultancy CE Delft, comes amid increasing scrutiny of non-CO₂ effects of aviation. However, the NGO says current efforts to monitor UFPs and other non-CO₂ emissions do not go far enough.

European Emissions Trading System (ETS) legislation approved in 2023 includes a mechanism for monitoring non-CO₂ effects, while the Ambient Air Quality Directive (AAQD) legislation requires the mandatory monitoring of UFPs, and considers airports air pollution hotspots, but does not define limits of UFP concentrations.

Rather than focusing on the potential climate impacts, the latest T&E/CE Delft study zooms in on potential health impacts of non-CO₂ and specifically on UFPs, which are approximately 1,000 times smaller than a human hair, making them difficult to measure but capable of penetrating deep into the human body—they have been found in the blood, brain, and placenta.

They are linked with heart, respiratory and neurological conditions, and pregnancy issues, among others, and as they are emitted at takeoff and landing as well as at altitude, they impact people living near airports.

“There is a strong need to analyze the impact of this tiny pollutant, which is today under-researched, overlooked, not monitored systematically, but also with potential high impact on air quality and human health,” said Carlos Lopez de la Osa, aviation technical manager at Brussels-based T&E, during a briefing ahead of the release of the study.  

T&E said sampling points should be installed in and around airports in European member states to better quantify UFP concentration levels, with a view to introducing UFP target values in the next revision of the AAQD.

In addition to better monitoring of UFPs, T&E calls for more hydrotreatment, a process already used in road transport and shipping to reduce the UFP emissions of standard kerosene, as the industry awaits the arrival of greater volumes of sustainable aviation fuel (SAF), which themselves emit fewer UFPs than standard kerosene.

Hydrotreatment can reduce UFPs at an estimated extra cost of around five cents per liter, T&E said. Use of 100% hydrotreated jet fuel with very low sulfur and aromatics could reduce up to 70% of the number of UFP emissions and would also reduce associated health impacts by 70%.

Lopez de la Osa told Aviation Week that it was “disappointing” that systematic monitoring of UFPs had not yet been put in place but that the organization wanted to portray tackling non-CO₂ effects as a straightforward solution to tackling aviation’s environmental impact at barely any political cost.

“It’s a bit disappointing to see how policymakers can’t agree on increasing ambition on something as basic as citizens breathing clean air,” Lopez de la Osa said. “We’re calling for reductions, ideally ambitious reductions, but the first thing is systematic monitoring—it’s not a huge ask. I’m hopeful that air pollution will become more and more a no-brainer.”

The study uses UFP concentration levels around Amsterdam’s Schiphol Airport—an airport whose impact on its surroundings is in the spotlight after government attempts to cap flights there to reduce noise—and extrapolates them to Europe’s main airports. The analysis estimates that a total of 280,000 cases of high blood pressure, 330,000 cases of diabetes and 18,000 cases of dementia may be linked to UFP emissions among the 51.5 million people living around Europe’s 32 busiest airports.

“This is a first estimation of what the impacts could be, and more epidemiological research should be done to give a more exact estimation,” said Daan van Seters of CEDelft, who co-authored the report with two colleagues, during the same briefing. “But what is important to realize is that these are big numbers,” co-author Stefan Grebe said. “This study indicates that it is really worth looking into it. It might be higher, or it might be lower. But it is something that should be researched because potentially it has very huge effects on health.”

Alongside better monitoring, T&E’s recommendations, which it published alongside the report, were for a ban on expanding airport infrastructure, the introduction of flight caps, the promotion of a shift to rail, a reduction in business travel, and targeted taxation of the aviation sector.

The organization also wants the European Commission to create a jet fuel standard which includes a progressive reduction of aromatics and sulfur, which will pave the way for 0-aromatic and 0-sulphur SAF.