742,00 people die every year worldwide from occupational cancers. These are caused by exposure to carcinogens in the workplace. They harm families and communities and cause unnecessary loss of people, skills and experience from the workforce. We can help you and your organisation understand the causes of occupational cancer and how to manage the risks.
Facts about silica dust
Individual silica dust particles are so small that they are invisible to the naked eye in normal light. This results in relatively high airborne concentrations with no visible or physical awareness that people are inhaling the dust.
A joint World Health Organization and International Labour Organization report estimates:
42,258 global deaths in 2016 were attributed to occupational exposure to silicaÂ
1.3 million disability-adjusted life years (DALYs) attributed to occupational exposure to silica in the same period.
What is silica?
Silica is a natural substance found in stone, rocks, sand and clay in its crystalline form. It is also found in bricks, tiles, concrete and some plastics. When these materials are worked on, for example when being cut or drilled into, crystalline silica is released as a very fine dust that can be breathed in. This dust causes significant ill-health effects, including silicosis and cancers.
There are other forms of silica that do not have a crystal structure and are referred to as amorphous silica. This can be found in diatomaceous earth, silica gel and synthetic amorphous silica.
Why is silica harmful?
Silica dust is only harmful when it’s inhaled deep into the lungs, where oxygen is transitioned into the blood. Silica can be found in sand but sitting on a sandy beach will not cause any respiratory harm because any sand particles breathed in will generally be too big to go beyond the nose or upper airways. It is the very fine airborne silica dust that can be harmful. This is known as the respirable fraction.
Respirable particles are typically less than around 5 micrometres (μm) in size. Compare this size to the ‘full stop/period’ at the end of the sentence, which is around 200-300 μm in diameter, and the finest sand on the beach, which is about 50-70 μm.
In 1996, the International Agency for Research on Cancer (IARC) reviewed the scientific evidence and concluded that crystalline silica dust is carcinogenic to humans. It is classified as a Group 1 carcinogen, meaning it is a definite cause of cancer in humans.
Exactly how silica dust causes lung cancer is unclear. The IARC suggests the most likely cause is when silica dust deposits in the lungs, the toxicity makes it difficult for the body’s natural defence cells to remove it. The dust remains in the lungs, causing persistent inflammation. This inflammation can damage deoxyribonucleic acid (DNA) in the lung cells and lead, in some people, to lung cancer.
What is the issue?
When respirable crystalline silica (RCS) is breathed in, it can cause a condition known as silicosis. This can be disabling or even fatal.
Silica dust enters the lungs and causes fibrosis (hardening or scarring) of lung tissue, as the body’s immune system tries to remove the RCS particles. This affects lung function and makes it difficult for the lungs to take in oxygen. People with silicosis will likely experience:
severe shortness of breath
coughing
difficulty in walking short distances, completing tasks or doing exercise
fatigue and a loss of mobility
fever
weight loss
becoming house- or bed-bound
chest pain
premature death, in some cases due to heart failure.
Silicosis usually occurs after 10 to 20 years of occupational exposure to RCS and is diagnosed via chest x-ray. There are three types of silicosis.
Acute silicosis – occurs after heavy exposure (over a short term) to RCS. It can also increase the risk of lung infections such as tuberculosis.
Accelerated silicosis – occurs after several years of high exposure levels to RCS.
Chronic silicosis – occurs after more than 10 years of exposure where the scarring and inflammation of the lungs develop over a longer time. This can lead to heart failure and premature death.
Unfortunately, silicosis continues to develop after exposure has ended and there is no cure for the condition. However, silicosis is preventable by controlling exposure to RCS.
Facts about asbestos
125 million people worldwide are thought to be exposed to asbestos in their workplace.
Estimated 233,000 occupational cancer deaths caused by asbestos every year.
Asbestos fibres are a thousandth of the diameter of a human hair. But you can see dust that contains fibres when asbestos-containing materials are damaged.
Types of asbestos
The common ones used were:
chrysotile (white asbestos)
amosite (brown asbestos)
crocidolite (blue asbestos).
Anthophyllite, actinolite and tremolite asbestos were less commonly used.
Where asbestos can be found
Asbestos millboard and papers – these have been used in specialist applications such as insulating electrical equipment and can contain high levels of asbestos.
Asbestos yarns – used for fire protective clothing, gloves and fire blankets, ropes, gaskets and packing materials. Cloth-containing asbestos has also been used in ceramic fuse holders behind fuse wires. 
Fibre cement – widespread use for roofing, wall cladding, soffit boards, boiler flues, gutters, pipes, tanks and bath panels. Fire bricks, lintels and surrounds were also made from asbestos cement.
Floor tiles, gaskets, bitumen, felts – where floor tiles have been bonded to the floor using bitumen there is often a residue of fibres left in the bitumen when the tiles are removed.
Insulating boards – these were produced to provide low-density, low-cost, fire-resistant insulation in many buildings. Asbestos can be found in ceiling tiles, partition walls, firebreaks, soffit boards and heater cupboards.
Laggings – used to prevent heat loss or heat transfer to surrounding areas. Found on boilers, pipes and other plant items. 
Mastics, sealants, putties and adhesives – used in boiler systems to attach insulation or fill gaps.
Reinforced plastics – including reinforced handles, automobile parts, housing for electronic equipment and toilet cisterns.
Spray coatings – used for fire protection on structural steel beams, trusses and girders, but also to prevent condensation inside buildings and for acoustic control. The coating comprised a thin layer of cement and fibre mixture applied by high-pressure spray.
Textured coatings and paints – often used to decorate walls and ceilings.
How to manage asbestos
The risk of contracting an asbestos-related disease depends on the asbestos type, concentration of fibres in the dust, duration of exposure, susceptibility of the individual and time since the first exposure.
Most countries require that people are not exposed to any airborne asbestos fibres, as there is no safe level of exposure. However, countries have different views on what limits to set for occupational exposure values for both eight-hour and short-term (15 minutes) exposure periods.
The asbestos limit values per country table on the German Social Accident Insurance website shows action should be taken to prevent or control asbestos exposure if a limit is reached. In Australia, for example, this is when 0.1 fibres are detected per CM3 of air averaged over a specified period (eight hours). It's important to state that any potential asbestos exposure should, at first, be prevented.
In the United Kingdom for example, there must be an asbestos management plan in place if the building that workers are in working on was built since the year 2000. 
Managers and business owners can follow the plan, do, check, act (PDCA) health and safety management system method. This features eight simple steps to avoid the accidental release of asbestos fibres.
Facts about diesel fumes
14,728 people who died between 2000 and 2016 due to occupational exposure to DEEE, according to the World Health Organization (WHO).
DEEE exposure limit value has been set at 0.05 mg/m3, measured as elemental carbon (EC). It came into effect in general occupational health environments in February 2023.
What are diesel engine exhaust emissions?
They are a mixture of gases, vapours, liquid aerosols and particles created by burning diesel fuels. They can contain:
alcohols
aldehydes
ammonia
aromatic compounds (benzene, polycyclic aromatic hydrocarbons and toluene)
carbon dioxide
carbon monoxide
carbon (soot particles)
fine diesel particulate matter (ash, carbon, soot, metallic abrasion particles, polycyclic aromatic hydrocarbons, silicates and sulphates). This can stay in the air for long periods of time, which allows the particulates to enter and penetrate deep into the lungs
hydrocarbons
ketones
nitrogen
nitrogen dioxide
nitrogen oxide
oxygen
sulphur dioxide
water vapour.
DEEE may contain more than 10 times the amount of soot particles than petrol exhaust fumes, and the mixture includes several carcinogenic substances. The International Agency for Research on Cancer, part of the WHO, has upgraded them to a group one carcinogen. They are treated as a cause of cancer in humans.
What's the issue?
Breathing in high quantities of DEEE can cause irritation in the respiratory tract within a few minutes of exposure, but prolonged exposure over many years may be more harmful.
The health effects will depend on:
the type and quality of diesel fuel being used (for example, whether it’s low sulphur)
the type and age of engine being used
where and how it’s used and maintained – blue or black smoke can indicate a problem with the engine, which could mean that more toxic fumes are being produced
the speed and workload demand on the engine
the state of engine tuning
the fuel pump setting
the temperature of the engine
the type of oil used
whether a combination of different diesel-powered engines is contributing to overall exposure
any emission control systems.
At the very least, short-term, high-level exposures to DEEE can irritate the:
eyes
throat
nose
respiratory tract
lungs.
It can also cause:
lung irritation
allergic reactions (causing asthma)
worsening of asthma
dizziness, headaches and nausea.
Continuous exposure to DEEE can cause chronic respiratory ill health, with symptoms including coughing and feeling breathless. If people are exposed to DEEE regularly and over a long period, there is an increased risk of lung cancer.