Is your worksite toxic?

Every year, thousands of people in New Zealand are hospitalised after being exposed to airborne contaminants at work. Often these contaminants can’t be seen with the naked eye, but after breathing them in over sustained periods of time, they can cause ongoing and long-term health problems, including lung disease.

Workers in the construction industry are 20 times more likely to die of exposure to harmful airborne contaminants than from a workplace accident – a big culprit is dust.

The risk is greatest when fine dust particles are inhaled during cutting, sanding, grinding, sweeping and polishing materials. This dust can also include dangerous materials such as lead oxide when working with old pipes, or the fine fibres when stripping out fibrous insulation. This risk is increased further when working on dry and exposed worksites, or when it is windy (as dust in the air increases).

While many work activities can create dust, the dust that can’t be seen is the dust that causes the most harm when inhaled. We discuss some of the risks below, and how you can stay protected in the workplace.

Wood dust

Wood can be in many forms such as softwood and hardwood, and wood-based products such as MDF and chipboard. Exposure to all types of wood dust can lead to the development of asthma and can trigger asthma attacks in existing asthma sufferers. There are even specific types of wood – western red cedar and iroko – that can cause a rare form of nasal cancer (extrinsic allergic alveolitis). Exposure to any type of wood dust can cause irritation, allergic rhinitis (runny nose) and impaired lung function.

Silica dust/respirable crystalline silica (RCS)

Large amounts of silica is present in most rocks, sand, and clay, and can also be found in granite and concrete.

Some silica dust is small enough that it is reaches deep inside the lungs when inhaled; this is called respirable crystalline silica (RCS).

Exposure to RCS over many years, or in extremely high doses, can lead to serious lung diseases, including fibrosis, silicosis, COPD and lung cancer. These diseases may cause permanent disability and early death.

Accelerated silicosis (rapid progression of the disease) is particularly dangerous for those working in the stone benchtop industry as the silica content of engineered stone is extremely high at 90% – much higher than natural stone at 25-40%.


Asbestos is classified as a category 1 carcinogen. When materials that contain asbestos are disturbed or damaged, fibres are released into the air which, when inhaled, can cause mesothelioma, asbestos-related lung cancer, asbestosis, and pleural thickening – all fatal or serious and incurable diseases which take many years to manifest. Asbestos is found in some roofing, in older insulation, textured paint on walls and ceilings, in some vinyl floor tiles and linoleum, and as backing on vinyl sheet flooring and adhesives. Anyone doing at-home DIY work, floorers, tilers, painters and decorators, and plasterers need to be aware of what materials may contain asbestos, and take the appropriate precautions when working with and destructing asbestos containing materials.

Managing these risks in the workplace

In addition to silica and asbestos, there are many other types of general construction dust, fumes, and sprays that can cause respiratory illness. It’s important that workers protect themselves by wearing the appropriate personal protective equipment (PPE) including respiratory protection, and go to their doctor if they have any symptoms including frequent dry coughing, shortness of breath, and wheezing.

Under the Health and Safety at Work Act 2015, employers also have a responsibility, as far as is reasonably practicable, to keep their workers not only safe but healthy as well. This means thinking about how risks like dust can be eliminated, isolated or managed.

For more information about respiratory health in the workplace visit or WorkSafe’s website:

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