Solvent exposure and Parkinson’s disease

Shaun Wood worked was a painter and finisher  at Royal Air Force (RAF) bases across the world. During the early 1990s he was involved in the very intensive work preparing Tornado aircraft for the first Gulf War, in particular gluing anti-missile patches to the aircraft. This work was often done in confined spaces over long working hours.  He generally wore a respirator but these were not really adequate for the circumstances.

German Tornado Undergoing Maintenance

Shaun has been diagnosed with Multiple System Atrophy (MSA), which is a debilitating Parkinsonian syndrome that affects the nervous system. He is just 53 years of age.

Throughout his work Shaun was exposed to various solvents, but primarily trichloroethylene and dichloromethane. There is not a great deal of information about exposure to these solvents in aircraft maintenance. I have seen results from a survey carried out at an RAF base in Scotland where dichloromethane levels were measured during paint striping in the cockpit area of a Nimrod aircraft. There was only 1.5 m2 of paint removed, but the peak air concentrations were about 700 mg/m3. Results from three monitoring surveys where the British Health and Safety Executive sampled for dichloromethane during paint stripping on aircraft are shown in the following figure. The mean levels measured in each of these surveys were: 330, 790 and 1,960 mg/m3, and the highest individual level measured was 3,590 mg/m3.

Read full article on OH-world.org A blog about exposure science and occupational hygiene

http://johncherrie.blogspot.ie/2011/12/solvent-exposure-and-parkinsons-disease.html

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Below is a photo of one of the locations in the Irish Air Corps that used Dichloromethane, namely the NDT Shop of Engine Repair Flight. Yes that is a stream of the chemicals dripping out of the extractor fan and running down the wall. And yes that is dichloromethane, cresylic acid and the hexavalent sodium chromate all over the floor. The small barrel that is being dissolved by its contents contains Hydrofluoric Acid.

Some extracts from the Ambient Air Monitoring For Health and Safety at Work report dated 2nd August 1995

  1. Dichloromethane levels were measured in the engine shop in Wednesday the 12th and Thursday the 13th of July 1995 at the behest of Captain John Maloney who is still serving in the Irish Air Corps
  2. The level of dichloromethane found in ambient air in the engine
    cleaning area exceeded health and safety limits. 
  3. Levels of Dichloromethane were measured at 175.9ppm (622.5 mg/m3)  while the TWA health & safety limit for this chemical in 1995 was 50ppm.
  4. Significant levels of all parameters monitored were found in nearly all ambient air samples taken in the engine cleaning area.
  5. The ventilation in all areas monitored was deemed to be insufficient. It is thus recommended that mechanical heating and ventilation systems be adapted designed and installed in all areas monitored.

To summarise, the Irish Army Air Corps knew that Dichloromethane levels in the NDT shop in 1995 exceeded health & safety limits by 3.5 times yet officer management

  1. LEFT personnel of all ranks and none to rot in this exceptionally toxic working environment for a further 12 years.
  2. IGNORED the recommendation to design and install design a proper ventilation system, (they stuck in 2 x Xpelairs).
  3. NEVER re-tested the environment to see if the Xpelair fans worked, we suspect they made things worse by increasing evaporation rate.
  4. NEVER informed personnel of enlisted ranks that their workplace was contaminated to dangerous levels.

DELAY – DENY – DIE

Hexamethylene Diisocyanate – Just one of the toxic chemicals the Irish Air Corps and State Claims Agency want to hide from former personnel!

  1. Exposure can occur when isocyanates are curing or when cured isocyanates are heated.
  2. An individual’s response to isocyanate exposure can be immediate or may be DELAYED FOR SEVERAL YEARS.
  3. Skin exposure can also cause respiratory sensitisation.
  4. The odour threshold for isocyanates, i.e. the level at which an individual can smell an isocyanate, is typically higher than the allowed exposure limits.
  5. The Air Corps did eventually provide a “supplied air” respirator to spray paint & welding personnel. Unfortunately they sourced the “supplied air” from an old machine compressor located in ERF where the air had previously tested as 3.5 times over the allowed limit for Dichloromethane i.e. allowed limit was 50ppm and sourced air was from a location measured at 175ppm…out of the frying pan and into the fire.

Air Corps Hexamethylene Diisocyanate Usage

Hexamethylene Diisocyanates were a chemical component of polyurethane paint hardener used by the Spray Paint Shop (Dope Shop) at Baldonnel. For most of the existence of this shop personnel were NOT supplied with ANY PPE. The walls between the Spray Paint Shop and Engineering Wing Hangar & Workshops were not sealed and so Hexamethylene Diisocyanate and other chemicals entered these workplaces whilst spraying was in progress exposing all personnel.

Furthermore if a component could not be removed from an aircraft for spray painting it was spray painted in-situ in Engineering Wing Hangar whilst unprotected line & tech personnel worked in adjoining offices & workshops or on other aircraft in the hangar.

Visiting personnel to Engineering Wing hangar such as BFTS personnel doing an IRAN, Heli personnel doing an overhaul & even Military Police on a walkabout were also exposed.

A “waterfall” system with an extractor fan was also present. Personnel spray painted aircraft components toward the waterfall which captured most of the over-spray droplets. Fumes from this waterfall were then extracted by a fan, up a duct and released at approximately 3m height where the prevailing winds then carried the extracted fumes in the doors & windows of : 

  • 5th Maintenance Engineers
  • Air Corps Apprentice School
  • Avionics Squadron
  • BFW Stores
  • Engine Repair Flight
  • Old Tech Stores
  • Training Wing HQ Prefab
  • Parachute Shop

5-20% of people are prone to isocyanate sensitisation. and isocyanate cross sensitisation is a recognised phenomenon. Sensitisation is irreversible and unfortunately once sensitised it is next to impossible to avoid isocyanate allergy triggers in the modern environment as they are used to make all Polyurethane products.

It is also likely that health effects are suffered beyond the respiratory system & skin for example the gastric & nervous systems and it is also probable that sensitisation to isocyanates will lead to allergies to other unrelated chemicals leading to a cascade of triggering chemicals allergies & intolerance for over exposed individuals.

DELAY – DENY – DIE