The escalating levels of air pollution in major Indian cities significantly impact the respiratory health of citizens, smokers, and non-smokers alike. This has led to a rapid surge in lung cancer cases, especially among young people. This results from chronic exposure to the harmful fumes that emanate from exhaust pipes, surface dust of tarred roads, burning of fossil fuels in factories and industries, and agricultural and household wastes. The most dangerous component of this noxious fume is the delicate particulate matter (PM2.5), which has been proven to cause lung cancer, heart disease, and respiratory problems like asthma flare-ups and bronchitis.
A recent study published in Nature Medicine shows that short-term exposure to ambient PM2.5 aggravates asthma and exacerbates COPD symptoms. The researchers also found that this pollutant causes oxidative stress and inflammation in the lungs, which in turn increases a person’s susceptibility to respiratory infections. Moreover, it also increases the rate of hospitalizations for acute respiratory exacerbation in patients with chronic obstructive pulmonary disease (COPD).
According to the GLOBOCAN 2018 report, tobacco smoking accounts for about 90 percent of all lung cancer deaths worldwide. The other major cause is environmental & occupational exposure to hazardous substances, particularly particulate matter (PM) and radon.
Exposure to air pollutants like PM2.5, ozone, and sulfur dioxide can increase the risk of lung cancer by causing oxidative stress and inflammation and increasing the number of free radicals in the body, which is an essential factor for carcinogenesis. This is why the IARC has listed air pollution as a Group 1 carcinogen, tobacco smoke, and ionizing radiation such as ultraviolet and ionizing radiation.
Particulate matter is a complex mixture of tiny solid and liquid particles in the air. These can be inhaled into the lungs and cause harm by damaging the lungs’ normal cells, and may also affect the DNA of these cells. Long-term exposure to air pollution can lead to mutations in the EGFR and KRAS genes, which increases the likelihood of developing NSCLC (non-small cell lung cancer).
These carcinogens are released mainly by coal- and gas-fired power plants, factories, vehicles, unpaved roads, agriculture, domestic cooking, and household smoke. It has been estimated that exposure to PM2.5 is responsible for around 265,267 lung cancer deaths globally, which is second only to tobacco smoke as the leading cause of lung cancer.
The WHO has recommended reducing outdoor PM2.5 exposure to reduce the risks of lung cancer and other diseases related to exposure to air pollution. The best way to do this is by living a healthy lifestyle and regulating daily activities based on the local air quality reports. It is also essential to take precautionary measures while traveling, as this can reduce the chances of exposure and help protect against adverse effects from air pollution; for those with chronic respiratory conditions such as COPD or asthma, regular treatments under physician guidance are required to prevent exacerbations.