What health risks are associated with asbestos and those tiny fibres?

Kiwis started using asbestos for buildings in the 1900s, and it wasn’t until the 1990’s that we stopped using it. In the interim, we found out it causes cancer and other irreversible harm.

After almost 100 years of use, most offices and homes in NZ have some form of asbestos in them, and almost all forms present some degree of risk. These naturally occurring minerals (called chrysotile, amosite or crocidolite) has been used in almost every aspect of building, making it a real, expensive, and dangerous problem.

Why Did We Build With Asbestos?

Asbestos was used mostly because of its excellent insulative properties. It’s non-corrosive, non-combustible, cheap, easy to weave in with other materials, and seemed like the answer to a range of issues when building. As a result, we can find it in NZ in:

  • Sprayed on coatings on structural supports and beams, to act as a fire retardant
  • Thermal pipe lagging, to keep cold pipes from freezing and retain heat in hot water
  • Ceiling panels and cladding, often mixed in with other materials
  • Floor tiles and lino
  • Roofing, which is easily recognised by its grey colour with a gentle wave, larger than steel
  • Ceiling stippling

You can imagine that with all these uses, you’ll find it in some form in almost every NZ building that was constructed before the year 2000. Because it’s often mixed with other things, asbestos has been found in more than 3000 different building materials.

Why Is Asbestos Such A Problem?

In itself, asbestos isn’t a problem. It’s when it is moved or removed; the tiny dust particles released can be incredibly toxic—in fact, they could kill you. This is why before you attempt any renovations, you must get all suspect products or aspects of your home tested. 

After the Christchurch earthquakes, there were huge fears that the destruction caused by the tremors would result in many people inhaling asbestos dust. After all, the shaking damaged a lot of building materials and caused many asbestos-containing materials to break up. As a result, all those working on rescue or demolition had to wear masks. There was a separate asbestos waste area set up in landfill ($365 a tonne for dumping compared with clean hard fill at $25 a tonne).

It was a huge fear, and one that may not be realised for many years. Many homeowners or businesses didn’t know if their buildings contained asbestos, and this highlighted the need for asbestos registers and testing before another disaster occurred.

What Does Asbestos Do To Humans?

There are four possible health outcomes from consuming asbestos in some form. The problem with asbestos is that it’s made from tiny fibres, called serpentine asbestos and amphibole asbestos. These include a variety of minerals, which when inhaled, get trapped in the lungs, accumulate, and cause scarring and inflammation.


This is the disease that is most commonly associated with asbestos. It affects the thin membranes of the chest and abdomen, with fibres causing scarring that lead to tumours growing in the pleural tissue outside the lungs and diaphragm. The symptoms include shortness of breath and chest pain. While it can take up to 40 years from exposure to tumour growth, once it’s established, life expectancy is only about 12 months from diagnosis. There is currently no cure.

Lung Cancer

Mesothelioma is not a form of cancer, but asbestos is carcinogenic, and it can cause cancer. This is the more common outcome of asbestos inhalation, with six times more cases than mesothelioma. About 3-4% of lung cancers are related to inhalation of asbestos fibres. These fibres become lodged in the lung tissue, which cause scarring and develop into cancerous tumours over time.

Symptoms of lung cancer include chest pain, shortness of breath, a persistent cough, and coughing up of phlegm.


This is the precursor to mesothelioma. The asbestos causes damage to the lung, which causes inflammation and scarring of the lungs. This gives severe and persistent breathing difficulties, shortness of breath, and chest tightness. As well as leading to mesothelioma, it can also cause lung cancer and even pulmonary heart disease, depending on where the asbestos has caused damage.

Pleural Thickening

This is the technical term for when the lung lining is thickened by scar tissue. This restricts the functions of the lungs and causes breathing difficulties. Pleural thickening can also be caused by tuberculosis, pneumonia, and empyema. This is benign, and no cure exists.

Asbestos Removal Must Be Done Correctly

Those asbestos fibres are tiny and undetectable unless tested for. Even trace amounts inhaled when doing minor renovation work can be unsafe. When carrying out any renovation work, even with PPE, there is a risk to you and your family. If you’re unsure, get TechClean to help with asbestos testing. Once any areas for concern are identified, we can advise on the best course of action to safely remove and dispose of the materials. 

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