Air Pollutants: Cancer-Causing Culprits In Our Atmosphere

Air pollution is a mixture of many harmful substances, including small particles in the air, sulphur oxides, carbon monoxide, nitrogen oxides, volatile organic compounds (VOCs), benzene and polycyclic aromatic hydrocarbons (PAHs). These toxic air pollutants can increase the risk of developing certain cancers by disrupting the way cells are produced in the body and mutating their DNA. In 2013, the International Agency for Research on Cancer (IARC) determined that there is enough evidence to say that outdoor air pollution can cause cancer in people.

Particulate matter (PM)

Air pollution has been linked to a variety of cancers. Regulators and scientists use the term 'air toxics' to describe chemicals that can cause cancer or other serious health issues such as asthma and heart disease. The International Agency for Research on Cancer (IARC) classifies types of air pollutants based on their link with cancer.

A 2022 study analysed 463,679 individuals to address the associations of increasing PM2.5 concentrations with cancer risk. The study also performed ultra-deep profiling of 247 normal lung tissue samples, analysed normal lung tissue from humans and mice following exposures to PM, and investigated the consequences of PM on tumour promotion in mouse lung cancer models. While the study found an association between PM and NSCLC, a direct cause-and-effect relationship remains to be proven.

Particulate matter is a complex mixture of solid and liquid particles suspended in the air. These particles can include acids, organic chemicals, metals, and soil or dust particles. The composition of PM varies depending on the source of the pollution and the surrounding environment. For example, PM from industrial sources may contain heavy metals and toxic chemicals, while PM from wildfires may contain high levels of organic carbon and black carbon.

The health effects of particulate matter depend on the size of the particles. Smaller particles, such as PM2.5, can penetrate deeper into the respiratory system and have more severe health impacts. Larger particles, such as PM10, are more likely to be filtered out by the nose and upper respiratory tract, but can still cause respiratory irritation and other health issues.

Reducing exposure to particulate matter can be achieved through a variety of measures, including wearing masks, using air purifiers, and reducing outdoor activities during periods of high pollution. Additionally, reducing the emission of particulate matter through the use of cleaner energy sources and more efficient industrial processes can help improve air quality and reduce the risk of cancer and other health issues associated with particulate matter pollution.

Sulphur oxides

The International Agency for Research on Cancer (IARC) classifies types of air pollutants based on their link with cancer. If an air pollutant is a known carcinogen, it can increase the risk of developing certain cancers by disrupting the way cells are produced in the body and mutating their DNA. These cancerous cells can then crowd out healthy cells, causing a cascade of effects.

One example of an air pollutant that has been linked to cancer is particulate matter (PM), which is associated with the risk of NSCLC. However, a direct cause and mechanism remain unknown.

Carbon monoxide

Air pollution has been linked to a variety of cancers, with outdoor air pollution being a particular cause for concern. A 2013 review by the International Agency for Research on Cancer (IARC) determined that there is enough evidence to say that outdoor air pollution can cause cancer in people.

One such air pollutant is carbon monoxide. Carbon monoxide (CO) is a colourless, odourless gas produced by the incomplete combustion of carbonaceous fuels such as wood, petrol, coal, natural gas and kerosene in simple stoves, open fires, wick lamps, furnaces, and fireplaces. The predominant source of carbon monoxide in the air is from motor vehicles.

Chronic exposure to carbon monoxide has been linked to shorter survival rates in glioblastoma patients. Glioblastoma is one of the most devastating primary brain tumours, with a median survival rate of 11 to 30 months. A retrospective observational study found that chronic exposure to carbon monoxide was associated with a 2-3 month reduction in survival rates.

While carbon monoxide is a harmful air pollutant, it is important to note that it is not the only one. Other air pollutants linked to cancer include particulate matter (PM), radon, sulphur oxides, nitrogen oxides, volatile organic compounds (VOCs), benzene, and polycyclic aromatic hydrocarbons (PAHs).

Nitrogen oxides

Additionally, nitrogen oxides can contribute to the formation of ground-level ozone, which is a major component of smog. Ozone is a powerful oxidant and can damage the cells in the respiratory system, further increasing the risk of cancer.

It is important to note that the risk of developing cancer from nitrogen oxide exposure depends on various factors, including the level of exposure, individual genetic factors, and other environmental influences. Reducing exposure to air pollutants, including nitrogen oxides, is crucial for lowering the risk of cancer and other serious health issues.

Volatile organic compounds (VOCs)

Air pollution has been linked to a variety of cancers. Regulators and scientists use the term "air toxics" to describe chemicals that can cause cancer or other serious health issues such as asthma and heart disease. The International Agency for Research on Cancer (IARC) classifies types of air pollutants based on their link with cancer.

VOCs can have both short- and long-term adverse health effects. Some VOCs can cause cancer in animals and are suspected or known to cause cancer in humans. Benzene, for example, is a known carcinogen. If you are exposed to a known carcinogen, it can increase your risk of developing certain cancers by disrupting the way cells are produced in your body and mutating their DNA. These cancerous cells can then crowd out healthy cells, causing a cascade of effects.

VOCs can also have short-term adverse health effects. Concentrations of VOCs are usually higher indoors than outdoors, and can be up to ten times higher than outdoor concentrations. Symptoms of exposure to VOCs include:

• Eye, nose, and throat irritation
• Headaches, loss of coordination, and nausea
• Damage to the liver, kidney, and central nervous system
• Allergic skin reactions

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