Air Toxins: Second Leading Cause Of Cancer

Air pollution is the second leading cause of lung cancer, after smoking. Fine particles in the air, known as particulate matter (PM2.5), can enter deep into the lungs and even enter the bloodstream, causing lung cancer. These particles are a mix of solid particles and liquid droplets, including soil, dust, soot, and smoke, and come from various sources, such as coal- and natural gas-fired plants, cars, agriculture, wildfires, and construction sites. While air pollution levels in the US are well below those in China, lower levels of particle pollution in the US have also been linked to lung cancer. The World Health Organization (WHO) estimates that 99% of the world's population breathes unhealthy air, and air pollution is estimated to cause nearly seven million deaths per year.

Particle pollution from vehicles, power plants, and industries

Air pollution is a significant and far-reaching threat to public health, with 99% of the world's population breathing unhealthy air, according to the World Health Organization (WHO). Exposure to air pollution can lead to cancer, stroke, respiratory and cardiovascular diseases, and other health issues.

Particle pollution, a mixture of solid particles and liquid droplets, is a major contributor to air pollution. It is released into the air through vehicle exhaust, coal-fired power plants, and other industrial sources. While individual car emissions are generally small, the large number of vehicles on the road and traffic congestion in urban areas result in significant air pollution. The burning of fuel in car engines releases pollutants such as carbon monoxide, nitrogen dioxide, and particulate matter. These fine particles can penetrate deep into the lungs and enter the bloodstream, causing serious health issues, including lung cancer.

Power plants, particularly those burning fossil fuels such as coal and natural gas, also contribute to particle pollution. The production of electricity by coal-fired power plants can cause more pollution than most cars. Additionally, motor vehicles and power plants burning sulfur-containing fuels, especially diesel and coal, release sulfur dioxide, which can form fine particles in the atmosphere.

Industries, including coal-fired power plants, contribute to particle pollution through the emission of pollutants such as volatile organic compounds (VOCs), nitrogen oxides, and particulate matter. These pollutants have adverse effects on human health, impacting nearly every organ system in the body.

Reducing particle pollution from vehicles, power plants, and industries is crucial for mitigating the risk of developing lung cancer and improving overall public health. This can be achieved through the adoption of cleaner energy sources, increased use of electric vehicles, and the implementation of policies and standards to reduce emissions.

Outdoor air pollution and lung cancer

Outdoor air pollution is a significant cause of lung cancer, with particle pollution from vehicle exhaust, coal-fired power plants, and other industrial sources posing the greatest risk. These particles, a mix of tiny solid and liquid particles, contain harmful components such as acids, organic chemicals, metals, soil, and dust. They can penetrate deep into the lungs, increasing the risk of early death, heart disease, asthma attacks, and interference with lung growth and function.

In 2013, the World Health Organization (WHO) concluded that particulate matter in outdoor air pollution causes lung cancer. This conclusion was supported by the case of an 8-year-old girl in China, the country's youngest lung cancer patient at the time, whose doctor attributed her illness to air pollution exposure. While air pollution levels in the United States have decreased due to the Clean Air Act, they have increased significantly in some parts of the world, particularly low- and middle-income countries with large populations.

The effects of outdoor air pollution on lung cancer vary geographically and demographically. For example, a study in China found spatial and gender heterogeneities in the association between outdoor air pollution and lung cancer incidence, with SO2 having the greatest influence on lung cancer in females in northern China. Similarly, a review of lung cancer risk models in Canada revealed spatial variations in the relationship between air pollution and lung cancer incidence.

Outdoor air pollution interacts with other risk factors, such as smoking, to increase the likelihood of lung cancer. In China, the combination of smoking and air pollution significantly elevated the risk of lung cancer in males. Additionally, certain populations are more vulnerable to the harmful effects of air pollution, including children, the elderly, people with lung and heart disease, and individuals with low incomes or those who work or exercise outdoors.

Reducing air pollution is crucial for mitigating the risk of lung cancer and improving overall health. Actions such as increasing green spaces, transitioning to cleaner energy sources, and promoting active transportation have the dual benefit of reducing air pollution and improving health outcomes, including lower rates of other non-communicable diseases.

Air pollution and cancer beyond the lungs

Air pollution is a significant and far-reaching threat to public health, with 99% of the world's population breathing unhealthy air, according to the World Health Organization (WHO). The risks associated with air pollution are similar to those caused by smoking tobacco. Indeed, exposure to air pollution can lead to cancer, stroke, respiratory, and cardiovascular diseases and other health issues. Air pollution is now estimated to cause nearly seven million deaths per year. This figure is comparable to the excess mortality caused by COVID-19 in 2020 and 2021.

Air pollution is caused by fine particulate matter – tiny airborne particles known as PM2.5 that are 2.5 micrometres in diameter or smaller – which is a mix of solid particles and liquid droplets that can penetrate deep into the lungs and even enter the bloodstream. This particulate matter includes soil, dust, soot, and smoke. It comes from various sources, such as coal- and natural gas-fired plants, cars, agriculture, wildfires, wood-burning stoves, unpaved roads, and construction sites.

In 2013, the World Health Organization (WHO) International Agency for Research on Cancer looked at all the available science and concluded that particulate matter causes lung cancer. That same year, an 8-year-old girl in China was diagnosed with lung cancer, becoming China's youngest lung cancer patient. Her doctor attributed her lung cancer to air pollution. Levels of exposure to air pollution have increased significantly in some parts of the world, mostly in low- and middle-income countries with large populations, according to the WHO. Unlike many industrialized and industrializing countries, air pollution levels in the United States have been decreasing, thanks mainly to the success of steps taken under the Clean Air Act.

While the focus has been on tobacco smoking, air pollution is a major cause of lung cancer, and the number of estimated lung cancer deaths has increased by nearly 30% since 2007 as smoking rates have decreased and air pollution has increased. Lung cancer risk models do not include air pollution, and estimation of cumulative exposure to air pollution is complex, which poses major challenges for accurately collecting long-term exposure data for incorporation into risk prediction models in clinical practice. Nevertheless, as smoking-related lung cancers decrease, the proportion of lung cancers in people who have never smoked will continue to increase. Increasing evidence indicates that air pollution is a major cause of lung cancer.

Reducing air pollution prevents lung cancer and promotes overall health with more green spaces, increased physical activity, and reduced disease rates. However, air pollution is threatening progress in reducing the burden of cancer worldwide by contributing to the rise in the number of cancer diagnoses each year. While reducing air pollution directly mitigates the risk of developing lung cancer, the actions to do so – such as increased green spaces, cleaner energy sources, and active transportation (walking and cycling) – also lead to a range of health benefits that can reduce the likelihood of developing other cancers.

Air pollution's impact on cancer treatment

Air pollution is a mix of tiny solid and liquid particles in the air, such as acids, organic chemicals, metals, soil, and dust particles. It is caused by human activities such as transportation and power generation. These particles can enter deep into the lungs and even enter the bloodstream. In 2013, the World Health Organization (WHO) reported that air pollution levels in the United States have been decreasing thanks to the Clean Air Act. However, the WHO also stated that air pollution levels have increased significantly in some parts of the world, especially in low- and middle-income countries with large populations.

Air pollution has been linked to an increased risk of various types of cancer, including lung cancer, breast, liver, and pancreatic cancer. It is estimated that nearly half of lung cancer cases in people who have never smoked are related to air pollution. In addition to lung cancer, air pollution has been associated with an increased risk of mortality for several types of cancer. For example, a study found that for every 10 micrograms per cubic meter (µg/m3) of increased exposure to PM2.5, the risk of dying from any cancer rose by 22 percent. The same study also reported even higher mortality risks for specific types of cancer, such as cancers of the upper digestive tract (42% higher risk), accessory digestive organs (35% higher risk), breast cancer (80% higher risk), and lung cancer (36% higher risk).

Air pollution can negatively impact the quality of life for people living with cancer. It can exacerbate respiratory symptoms, increase fatigue, reduce physical activity, and worsen treatment side effects. Additionally, air pollution may interfere with cancer treatments, reducing the effectiveness of chemotherapy drugs, increasing surgical complications, and potentially interacting with targeted therapies and immunotherapies.

While the impact of air pollution on cancer treatment is a global concern, low- and middle-income countries bear the heaviest toll, with nearly 90% of premature deaths related to air pollution occurring in these regions. This disparity is due to limited access to early detection and treatment options in these countries.

To address the impact of air pollution on cancer treatment, global efforts are being made to raise awareness, advocate for clean air action, and encourage governments to take more aggressive action to reduce air pollution. These include initiatives by organizations such as the UICC, which applied for a grant from the Clean Air Fund to fund a two-year project aimed at raising awareness about air pollution as a preventable cancer risk factor.

Reducing air pollution to prevent cancer

Air pollution is a significant and far-reaching threat to public health, with 99% of the world's population breathing unhealthy air. It is the second leading cause of lung cancer, and exposure to it increases the risk of developing lung cancer and other serious illnesses.

Reducing Air Pollution

As individuals, we can take steps to reduce our contribution to air pollution. We can make more journeys by walking, cycling, or using public transport, which lowers emissions compared to driving. We can also reduce the amount of heating and cooling in our homes by ensuring proper insulation and ventilation. Switching from a coal or wood-burning heat source to an electric, natural gas, or oil heat source can also help improve indoor air quality.

Government Action

Governments also have a crucial role in reducing air pollution. The World Health Organization (WHO) has developed tools such as AirQ+ and the Carbon Reduction Benefits on Health (CaRBonH) calculation tool to assist governments in taking action. These tools help assess health risks and quantify the economic benefits of improving air quality. Additionally, individuals can advocate for stronger air pollution regulations and support initiatives like the Clean Air Act in the United States, which has successfully reduced air pollution levels.

Health Benefits of Reducing Air Pollution

Reducing air pollution has direct health benefits, including the mitigation of lung cancer risk. It also promotes overall health by providing more green spaces, encouraging increased physical activity, and reducing disease rates. Lowering air pollution can lead to a healthier diet, reduced respiratory symptoms, and decreased interference with cancer treatments.

Preventative Measures

While we cannot avoid air pollution entirely, we can take preventative measures to reduce our risk of cancer. These include not smoking, maintaining a healthy weight, practising sun safety, and consuming alcohol in moderation. By combining individual actions with government initiatives, we can effectively reduce air pollution and mitigate the risk of cancer and other health issues.

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