Particulate matter from aircraft engines affects airways

According to the World Health Organization (WHO), seven million people worldwide die as a consequence of air pollution every year. For around 20 years, studies have shown that air-borne particulate matter negatively affects human health. Now, in addition to already investigated particle sources like emissions from heating systems, industry and road traffic, aircraft turbine engine particle emissions have also become more important.

Photo of Alouette III No 196 showing soiling of the tail boom with soot from exhaust gasses.

In a unique, innovative experiment, researchers have investigated the effect of exhaust particles from aircraft turbine engines on human lung cells.

The cells reacted most strongly to particles emitted during ground idling.

It was also shown that the cytotoxic effect is only to some extent comparable to that of particles from gasoline and diesel engines.The primary solid particles, i.e. those emitted directly from the source, have the strongest effect on people in its immediate vicinity. 

Now a multidisciplinary team, led by lung researcher Marianne Geiser of the Institute of Anatomy at the University of Bern, together with colleagues from Empa Dübendorf and the University of Applied Sciences and Arts Northwestern Switzerland (FHNW), has shown that primary soot particles from kerosene combustion in aircraft turbine engines also cause direct damage to lung cells and can trigger an inflammatory reaction if the solid particles are inhaled in the direct vicinity of the engine.

The researchers demonstrated for the first time that the damaging effects also depend on the operating conditions of the turbine engine, the composition of the fuel, and the structure of the generated particles.

Beechcraft 200 Super King Air No 240 showing soiling of the engine panels with soot from exhaust gasses.

Extremely small particles in the nanoscale range

Particles emitted from aircraft turbine engines are generally ultrafine, i.e. smaller than 100 nm. By way of comparison, a human hair has a diameter of about 80,000 nm. When inhaled, these nanoparticles — like those from other combustion sources -efficiently deposit in the airways. In healthy people, the well-developed defense mechanisms in the lungs normally take care of rendering the deposited particles ineffective and removing them from the lungs as quickly as possible.

However, if the inhaled particles manage to overcome these defense mechanisms, due to their structure or physico-chemical properties, there is a danger for irreparable damage to the lung tissue. This process, already known to researchers from earlier experiments with particle emissions from gasoline and diesel engines, has now also been observed for particle emissions from aircraft engines.

Toxicity depends on the operating conditions of the turbines and the type of fuel

Evidence of increased cell membrane damage and oxidative stress in the cell cultures was identified. Oxidative stress accelerates ageing of cells and can be a trigger for cancer or immune system diseases.

Overall, according to the researchers, it has been demonstrated that the cell-damaging effect caused by exposure to particles generated by the combustion of gasoline, diesel and kerosene fuel are comparable for similar doses and exposure times.

Additionally, a similar pattern was found in the secretion of inflammatory cytokines after exposure to gasoline and kerosene fuel particles.

Aerosols: distance from the source is crucial

Aerosols are the finest solid or fluid substance suspended in the air. In combustion processes, the composition of ultrafine particles is highly variable. In addition, aerosols are unstable, and they are modified after their formation. Primary ultrafine solid particles have a high diffusion velocity. As a result, at high concentrations such particles either stick together or attach to other particles. Therefore, the effect of primary ultrafine particles depends on the distance from the source, implying that there is a difference depending on whether a person is close to the source (such as people at the roadside ) or at a greater distance (aircraft taxiing or taking off). Further research is needed to clarify how strong the impact would be at a greater distance from an aircraft engine

Read full article in ScienceDaily

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The layout of the Irish Air Corps base at Casement Aerodrome ensures that aircraft exhaust gasses are blown over populated sections of the airbase when winds are from the south, south east or south west. This includes hangars, offices, workshops and living in accommodation such as the apprentice hostel and married quarters. Calm weather also creates conditions where exhaust gasses linger in higher concentrations.

This results in all Irish Air Corps personnel (commissioned, enlisted, civilian & family) being exposed to emissions from idling aircraft engines, emissions that are known to cause harm.

In the mid 1990s a study of air pollution adjacent to the ramp area at Baldonnel was commissioned. This report relating to this study has gone missing. 

  • Anecdotal evidence suggests increased prevalence of occupational asthma & adult onset asthma amongst serving & former personnel who served in Baldonnel or Gormanston aerodromes. 
  • Older gas turbine engines produce dirtier exhaust gasses.
  • Idling gas turbine engines produce dirtier exhaust gasses.
Below are some of the gas turbine powered Air Corps aircraft that were powered by elderly engine designs.
AircraftRetiredEngine FamilyFirst Run
Alouette III2007Turbomeca Artouste1947
Fouga Magister1999Turbomeca Marboré1951
Gazelle2005Turbomeca Astazou1957
King Air 2002009Pratt & Whitney Canada PT61960
Dauphin II2005Turbomeca Arriel1974

DELAY – DENY – DIE

RAAF jet fuel damaged ground crews’ body cells; long-term consequences unknown, says groundbreaking research

Royal Australian Air Force (RAAF) personnel who worked with widely used jet fuel suffered damage to their body’s cells with unknown long-term consequences, according to groundbreaking research released after a Freedom of Information laws request.

Defence’s senior physician in occupational and environmental medicine, Dr Ian Gardner, described the findings as a “part of the puzzle” and a hypothesis-making study”, and pointed it out that it was one of a series of pieces of research currently underway.

“What it shows is there is evidence of small but persistent cellular damage,” Dr Gardner told the ABC. He said it was not yet clear what the long-term effects of that damage might be.

“For the future though there are a lot of other aircraft maintenance workers who have done similar jobs on other aircraft types, and now Defence and DVA and Air Force are considering what additional work should be done in relation to those other people who are not actually on the F-111 programs but have done essentially similar work,” Dr Gardner said.

The Jet Fuel Syndrome Study also shows that the fuel is more toxic to the body’s cells than the two solvents initially blamed for the sickness suffered by the deseal/reseal workers, and that the toxicity is even higher when those solvents and the fuel were mixed.

The results of the research project, headed by Professor Francis Bowling of Brisbane’s Mater Hospital, were handed to Defence last September, and have been the subject of significant scrutiny and review due to the potential significance of the findings.

They will give heart to former and serving Defence personnel who believe they have been left out in the cold by Defence after developing serious health complaints while working with fuel and other substances.

Read full article on ABC Australia from 2015

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Junior Minister with responsibility for Defence said in the Dáil that he was assured by the Irish Air Corps that the RAAF F1-11 deseal/reseal exposure tragedy is completely different to any exposures at the Irish Air Corps.

Was the minister suggesting that Irish Air Corps gas turbine engines don’t run on jet fuel?

DELAY – DENY – DIE

Biological monitoring for Isocyanates

Organic diisocyanates are a significant occupational health problem.

They are respiratory and skin sensitizers and a major cause of occupational asthma in the UK. The most common are hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), isopherone diisocyanate (IPDI) and methylene-diphenyl diisocyanate (MDI) in decreasing order of volatility. HDI and IPDI are used for varnishes, coatings and two-pack spray paints used in motor vehicle repair. TDI and MDI are used for flexible and rigid polyurethane foams, floor coverings and adhesives. This wide range of uses means that there are thousands of workers potentially exposed to isocyanates.

In the UK, a management control system is required for workers exposed to isocyanates and for this to be successful workers should not become sensitized. Apart from occupational asthma, airway irritation and asthma-like symptoms such as cough, wheezing and dyspnoea are commonly reported. Other respiratory effects are hypersensitivity pneumonitis, rhinitis and accelerated rate of decline in lung function. Diisocyanates can also cause both irritant and allergic contact dermatitis as well as skin and conjunctival irritation.

Health surveillance that detects occupational asthma is recording failure – there needs to be intervention earlier in the exposure-to-disease paradigm. Although there is evidence that detecting respiratory symptoms early and removing workers from exposure improves prognosis, the goal should be to control exposure to prevent any symptoms.

Please read more on the Society of Occupational Medicine website from September 2007.


This is a long article but a very informative read and is especially relevant for those on post 1995 contracts who were dismissed from the Irish Army Air Corps due to occupational asthma.

New Locations & New Illnesses

We are delighted to announce that No3 Support Wing (Helicopter Wing) & Gormanston Camp have joined the list of toxic sites with staff suffering life threatening illness.

We are also delighted to announce that we have added Hypokalemia and Occupational Asthma to the illness list.