Air Quality in the Auckland Fire Smoke

What pollutants are expected in the smoke and what is the risk to health?

Auckland Convention Centre

The recent fire in the Auckland Convention Centre will likely contain a number of toxins that will be a risk to health.  The closer to the source, the greater the risk.  The toxins from the smoke will decrease as the fire is extinguished.   The toxins are expected to persist for a long time after the fire has been put out.

Pollutants and Health Effects

Some toxins can remain in properties for over a year after the event. Peoples reaction to the smoke will vary from person to person. People with pre-existing respiratory health issues, the young and the old are expected to be more affected.

What is Smoke?

Smoke is a mixture of toxic gases and particulates.  There will be thousands of different compounds present.  Detailed below are some of the more commonly known compounds that can be expected to be present in high concentrations.

What compounds are present will be dependent on the products being burnt.  Substances such as foam, textiles and plastics can be safe in a home or workplace.  Once they are combusted they create a dangerous cocktail of compounds.

Recommended Action

If you are in a property affected by smoke, leave the building until all traces of the smoke have gone.  This may take days as air conditioning systems can be overloaded with toxins and will require a complete service.  The air conditioning systems will spread the toxins throughout the building.

Toxins can enter the body via the skin, the eyes as well as inhalation. If you are entering the affected area you must use a fit tested mask with an organic cartridge and a P3 filter. Limit the time in the areas to the minimum.

Before entering an area with no protection have the area assessed by a company such as K2 Environmental. Be confident that any toxins present are at a safe level.

People who live in smoke affected properties are likely to be more at risk than those that work in a building for 8 hours a day.

Before Reoccupation – Lower the Risk

This is an unprecedented event.

What is burning at the Auckland Convention Centre? The bitumen roof coating. At high temperature (unlike burning wood) heavy hydrocarbons that do not burn out will vaporise and later condense in the air into tiny black droplets (condensable particulate).

These particulate droplets will stick to the windows and walls.

This is also an unusual load for HVAC systems. There is a chance that what gets accumulated on the filters now will be off-gassing for many months. The accumulation can also block the filters as the particles can be oily in nature.

Homeowners and property managers should have the filters replaced when the fire is fully extinguished. Or make sure they have not become a source of secondary contamination.

Smoked Fish

If you were to catch a fish and smoke it then it has changed forever. No amount of fog treatment or ozone treatment is going to transform the fish back to the un-smoked state.

The same can apply to contents of properties heavily affected by smoke. Some can be cleaned an returned to the original state. Those that have had the smoke absorbed into them and transformed the options are limited.

What Pollutants Will be Present

Particulate – Ultra Fine Particulate

Smoke will contain particulate of a range of sizes.  The smallest will be ultra-fine particles, which will be down to ten nanometre’s in size.  One nanometre is a metre divided by 1,000,000,000.

The health effects from ultra-fine particulate can be:-

• Irritation to the eyes, nose and throat
• Headaches, fatigue and nausea
• Aggravation to respiratory and skin conditions, such as asthma or eczema

Black Carbon – Particulate

The fire will generate black carbon. Black carbon particles will be very small and will progress deep into the lungs. 

Black carbon is a health risk due not only to its small size but also the likelihood that it will have absorbed other toxic gases to it. The dark colour of the plume indicates there will be very high amounts of black carbon in the air.

Determination of black carbon in the air can be carried out with a specialised electronic meter owned by K2 Environmental.

Fine Particulate

Fine particulate are particles that are typically less than 2.5µm and smaller. These, like the ultra-fine particulate, will remain airborne for a long time and will travel large distances.  

The fine particulate can also have other toxins absorbed to it.

Organics

What organic compounds are expected to be present in the plume?

Volatile Organic Compounds

This typically includes compounds such as:-

• benzene,
• toluene
• xylene
• ethylbenzene

There will be hundreds of other volatile organic compounds present.  If there are any plastics burnt then it can be expected to find organochlorine compounds.  Many of these have carcinogenic properties.

Aldehydes and Ketones

The fire will generate formaldehyde and acrolein.  Each is highly toxic and formaldehyde has been listed as a probable carcinogen.

 Acrolein can irritate the nose and throat at low concentrations.  Other health effects of acrolein are irritation of lungs, coughing and shortness of breath.

There will be other toxic aldehydes generated in the fire that have significant health effects.

Dioxins and Furans

Dioxins are generated through low temperature combustion in the presence of chlorine.  The fire will have areas of low temperature combustion and chlorine will be present in plastics. 

Dioxins and Furans are highly toxic and can have long lasting health effects.

Poly Aromatic Hydrocarbons (PAH)

The short term health effects from PAH include eye irritation, nausea and vomiting.  The combustion of bitumen products is expected to generate PAH compounds.  There are many other health effects from PAH compounds. 

PAH compounds can be expected to last for a long time after a fire.

Other Toxic Compounds

What other toxic compounds are expected in the plume?

• Hydrogen cyanide and other cyanide compounds – there are numerous mechanisms for these to be generated.  They can be generated by combustion of nitrogen containing compounds such as:-
  • Wool
  • Nylon
  • Paper
  • Rubber
  • Polyurethanes
• Ammonia
• Hydrochloric Acid
• Hydrogen sulphide
• Phosgene

Combustion Gases

The smoke will contain typical combustion gases such as:-

• Carbon dioxide
• Carbon monoxide
• Sulphur dioxide
• Nitrogen dioxide
• Nitric oxide
• Other nitrogen oxides

Each of these compounds will have health effects.  The closer to the source of the fire, the greater the exposure expected